ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Traditional Poster Session • Neuro 2
2140 -2163 Stroke & Neurovascular: Animal Studies
2164 -2195 Stroke & Neurovascular: Human Studies
2196 -2214 Mechanisms of Neural Degeneration & Damage
2215 -2234 Alzheimer's Disease
2235 -2246 Brain Tumour Spectroscopy
2247 -2257 Brain Tumour Multiparametic Assessment
2258 -2267 Brain Tumour Diffusion
2268 -2278 Brain Tumour Perfusion & DCE
2279 -2282 Brain Tumours & fMRI
2283 -2288 Novel Brain & Eye
2289 -2321 Head & Neck & Beyond

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2140.   Time-Dependent Influence of Hypoxic Ischemic Encephalopathy in Cerebral Metabolite Changes in Neonatal Rats Detected by In vivo 1H MR Spectroscopy at 9.4 T
Do-Wan Lee1,2, Dong-Cheol Woo2, Minyoung Lee2,3, Chul-Woong Woo2, Sang-Tae Kim2, Choong Gon Choi4, Bo-Young Choe1, and Byong Sop Lee3
1Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Seoul, Korea, 2Asan Institute for Life Sciences, Asan Medical Center, Seoul, Seoul, Korea, 3Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea,4Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

The purpose of this study was to quantitatively determine the influence of the time-dependent effects of hypoxic-ischemic-encephalopathy (HIE) on cerebral metabolite changes in a neonatal rat model of severe HIE. Our results exhibited that a total of 16 metabolite signals in HIE rats were significantly altered with increased periods of development (at PD7, PD14, and PD28), compared to the CNTL. The present study is unique in that we discovered not only the usefulness of traditional markers (NAA, Cr, and choline-containing-compounds) but also several new results (Ala, Asp, Glu, Gln, and GSH, etc.) from a neonatal rat model of severe HIE.

2141.   Marked perturbations in CBF and CO2 reactivity in subarachnoid hemorrhage
Yuhao Sun1,2, Qiang Shen1, Shiliang Huang1, and Timothy Q. Duong1
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China

Subarachnoid hemorrhage (SAH) is a medical emergency. Vasospasm is widely reported. However, its effects on cerebral blood flow (CBF) and cerebrovascular reactivity are seldom studied. We found SAH induced marked perturbations of basal CBF and cerebrovascular reactivity in an established animal of SAH from day 0 to 7. CBF and cerebrovascular reactivity recovered gradually by day 7. This study investigated the effects of SAH on CBF and CO2 reactivity in an established rat model. We concluded that hemodynamic disturbance in the brain after subarachnoid hemorrhage could contribute to progressive neurological deficits.

2142.   Chronic cerebral hypoperfusion induces cerebral hemodynamics and angiogenesis
Shi Chang-Zheng1, Jing Zhen1, Ruan Yiwen1, and Huang Li¡¯an1
1Jinan University, Guangzhou, Guangdong, China

Most pathological changes were elicited when BCCAO was induced simultaneously at both the left and right CCAs. Another model was later introduced where BCCAO was induced with one week interval between the first and second CCA occlusions . The latter allows gradual development of CCH within the brain. Although the pathological mechanisms of these models have been widely studied, dynamic changes in CBF and angiogenesis are not completely understood.

2143.   Time-to-Peak of T2*-Weighted Signal Change of Oxygen Challenge Improves the Identification of Penumbra in Ischemic Stroke
Qiang Shen1, Shiliang Huang1, and Timothy Q Duong1
1Research Imaging Institute, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States

Percent change of T2*-weighted signal following oxygen challenge (OC) has been used as a biomarker of penumbra. However, T2*-weighted MRI of OC challenge in delineating tissue at risk has low contrast-to-noise sensitivity and there are significant false positive and negative pixels, particular from pixels that contain large vessels. In order for this biomarker to be practical, it is necessary to improve its specificity and sensitivity. The goal of this study was to explore the use of the time-to-peak of OC response to further improve the identification of at-risk tissue in ischemic stroke.

2144.   Diffusion-weighted Spatiotemporal Encoding Schemes in the Assessment of SPIO-labeled Cell Therapy for Ischemic Stroke
Jens T Rosenberg1,2, Avigdor Leftin3, Eddy Soloman3, Lucio Frydman1,3, and Samuel C Grant1,2
1National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, United States, 2Chemical & Biomedical Engineering, Florida State University, Tallahassee, FL, United States, 3Chemical Physics, Weizmann Institute of Science, Rehovot, Israel

Diffusion-weighted spatiotemporal encoding (DW-SPEN) was used to evaluate a pre-clinical in vivo model of ischemic stroke under treatment with super-paramagnetic iron-oxide labeled human mesenchymal stem cells at 21.1 T. In the presence of the induced background susceptibility gradient, this work demonstrates more robust quantification of in vivo diffusion parameters in DW-SPEN to DW-EPI and DW spin-echo acquisition methods.

2145.   Detection of subtle hypoxic-ischemic injury by oscillating gradient diffusion MRI in neonatal mouse brain
Dan Wu1, Frances J Northington2, Lee J Martin3, and Jiangyang Zhang4
1Biomedical Engineering, Johns Hopkins University School of Medicine, BALTIMORE, Maryland, United States, 2Pediatrics, Johns Hopkins University School of Medicine, Maryland, United States, 3Neuroscience, Johns Hopkins University School of Medicine, Maryland, United States, 4Radiology, Johns Hopkins University School of Medicine, Maryland, United States

The oscillating gradient diffusion MRI (OGSE) is useful in probing restricted diffusion in short-diffusion time, and thus is sensitive to microstructural changes in small scales. We used OGSE (50-200Hz) to examine hypoxic-ischemic (HI) injury in neonatal mouse brains at 3hrs and 24hrs after injury. Compared to PGSE, OGSE results revealed elevated ADC in external capsule in mild injury mice at 3hrs post-HI, and expanded lesion areas around the external capsule at 24hrs post-HI. The enhanced edema contrast in OGSE-ADC maps may correlate with microstructural pathology in astrocytes as shown in histology.

2146.   Assessment of Blood Brain Barrier Permeability in the Rat Brain with Ischemic Occlusion Using DSC-MRI
Ramesh Paudyal1, Silun Wang1, Yonggang Li2, Byron D Ford2, and Xiaodong Zhang1
1Yerkes Imaging Center, Yerkes Regional Primate Research Center, Emory University, Atlanta, GA, United States, 2Neurobiology, Neurosciences Institute, Morehouse School of Medicine, Atlanta, GA, United States

The aim of this study was to assess the blood brain barrier permeability in a rat stroke model induced by a permanent middle cerebral artery occlusion (i.e., pMCAo) using dynamic susceptibility contrast-MRI at 48 hr. Our findings demonstrated that a leakage corrected blood volume indicated the disruption of BBB in ischemic injury at 48 hr.

2147.   Combine Diffusion Tensor Imaging and RGMa Immunohistochemical Analysis to Evaluate the Crossed Cerebellar Diaschisis in Rats after Middle Cerebral Artery Occlusion
Yong Zhang1, Jiangliang Cheng1, Yanan Lin1, Lu Yang1, Shanshan Zhao1, and Dandan Zheng2
1Dept. of MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China, 2GE Healthcare, China, Beijing, China

The mechanism of cerebral infarction might be related to the theory of crossed cerebral-cerebellar diaschisis which pointed out that supratentorial focal brain damage could cause short functional changes in its fiber linked distant areas. In this study, we detected FA and the RGMa protein expression in remote regions of the infarct core in rats after MCAO at a continuous time point. The two values were analyzed to reveal the diffusion condition and pathological changes of the bilateral cerebellar hemispheres and hope to give more evidences about the relevant mechanism of crossed cerebellar diaschisis.

2148.   The Role of Collateral Circulation in Perfusion and Diffusion MRI after Stroke
Yu-Chieh Jill Kao1,2, Esteban A Oyarzabal1, Hua Zhang3, James E Faber3, and Yen-Yu Ian Shih1
1Neurology and BRIC, University of North Carolina, Chapel Hill, NC, United States, 2Imaging Research Center, Taipei Medical University, Taipei, Taipei, Taiwan, 3Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, United States

By using two genetically engineered mouse strains that differ in collateral extent, the present study demonstrated that collateral circulation significantly suppresses the expansion of ischemic core, restores area with cerebral blood flow deficit and reduces final infarct size.

2149.   Monitoring Response to Neuregulin-1 in a Rat Model of Stroke Using Perfusion- and Diffusion Weighted MRI
Ramesh Paudyal1, Yonggang Li2, Silun Wang1, Byron D. Ford2, and Xiaodong Zhang1
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Neurobiology, Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States

Neuregulin-1 (NRG-1) has shown the neuroprotective effects in ischemic brain injury by reducing infarct volume and protecting neurons from ischemic damage. This study evaluates the neuroprotective effect of NRG-1 in a rat stroke model induced by permanent middle cerebral artery occlusion (pMCAo) using perfusion-and diffusion weighted magnetic resonance imaging (MRI) at 3hr and 48 hr and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and cresyl violet staining (CV) at 48 hr. Results showed that the vehicle treated group has a significantly greater ischemic lesion volume and mismatch region at 3hr than NRG-1 treated group. Our finding showed that NRG-1 served as a potent neuroprotectants in ischemic injury.

2150.   Absolute T1 and T2 Relaxation Times; Proxies for Onset Time and Tissue Status Assessment in Acute Ischaemic Stroke
Harriet J Rogers1, Bryony L McGarry1, Kimmo T Jokivarsi2, Michael J Knight1, Alejandra Sierra Lopez2, Olli HJ Gröhn2, and Risto A Kauppinen1
1School of Experimental Psychology and CRIC, University of Bristol, Bristol, United Kingdom, 2Department of Neurobiology, University of Eastern Finland, Kuopio, Finland

Thrombolytic therapy for acute ischaemic stroke requires known symptom onset time, however for many patients this is unknown. We determined time-dependent changes of T1and T2 in ischaemic rat brain. Both T1 and T2 relaxation times increased linearly in the ischaemic lesion for the observation time of 5 hours. T1and T2 prolongation occurred in different regions in early moments and overlapped at later time-points. Volume of overlap increased linearly with time, thus combining these parameters provides a further proxy for stroke onset time and assessment of tissue status. Quantitative relaxometry bears potentials for acute stroke patient stratification.

2151.   Effect of motor cortex lesions on brain connectivity of rhesus monkeys
Bang-Bon Koo1, Mary Orczykowski1,2, Kevin Arndt1, Yansong Zhao3, Tara Moore1, and Ron J. Killiany1
1Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, United States, 2Boston University School of Medicine, MA, United States, 3Philips Healthcare, Cleveland, OH, United States

In this work, we investigated causal relationships on the lesions on both cognitive and brain structural and resting-functional network changes in rhesus monkeys.

2152.   Chronic methylene blue treatment decreases ischemic stroke volume and improves functional behavioral recovery
Pavel Rodriguez1, Jiang (John) Zhao1,2, and Timothy Q. Duong1
1Research Imaging Institute, The University of Texas Health Science Center, San Antonio, Texas, United States, 2Department of Anatomy and Embryology, Peking University Health Science Center, Beijing, United States

We previously reported that a single-dose methylene blue (MB), an energy-enhancing drug, given hyperacutely reduced infarct volume in permanent and transient MCAO in rats using MRI up to 2 days. This study investigated the effect of chronic MB therapy on ischemic stroke volume along with behavioral score correlations 28 days after stroke. We administered MB at day 0, 2, 7, 14 and obtained stroke volume and functional behavioral measurements out to 28 days. We also used a new more aggressive treatment paradigm that involves doubling MB dose over permanent ischemia and after reperfusion. We hypothesized that this new MB treatment paradigm is safe, decreases final stroke volumes and functional sensorimotor deficit.

2153.   ADC correlates of CBF and Tissue PO2 in global cerebral ischemia
Yash Vardhan Tiwari1,2 and Timothy Duong1
1Research Imaging Institute, UT Health Science Center, San Antonio, Texas, United States, 2Biomedical Engineering, UT, San Antonio, Texas, United States

Apparent diffusion coefficient is a highly sensitive marker for ischemic insult, but lacks desired specificity in distinguishing salvageable versus non-salvageable tissue. There is an ever urgent need to define ADC threshold correlates of cerebral blood flow (CBF) and tissue deoxygenation in ischemia. This study incorporated simultaneous tPO2 measurement with interleaved perfusion and diffusion MRI at high temporal resolution to measure patterns of ADC changes in correlation to CBF and tPO2 response immediately following global cerebral ischemia.

2154.   Assessment of Experimental Stroke Lesion Size Using 1T Benchtop MRI
Jed Wingrove*1, Daniel Stcukey*1, Valerie Taylor1, Thomas Roberts1, Rajiv Ramasawmy1, Bernard Siow+1, and Mark Lythgoe+1
1Centre for Advanced Biomedical Imaging, Department of Medicine, University College London, London, United Kingdom

Small animal stroke research commonly uses histological analysis for the evaluation of pathological severity, however, histology precludes longitudinal studies of stroke evolution. Non-invasive, in vivo MRI has become increasingly prominent in pre-clinical settings, hugely benefiting the prediction of long-term pharmacological outcomes. However, most pre-clinical MRI systems operate at high field (≥ 4.7T), requiring cryogen cooling and are expensive to purchase and maintain. Recently, low-field (1T) “benchtop” MRI scanners have emerged which may be a cost-effective alternative. In this study, we demonstrate that a 1T benchtop MRI scanner is well suited to assessing stroke lesions in a rodent model of stroke.

2155.   Age Dependent Differences in Photothrombotic Ischemic Injury Detected Using Quantitative MR Imaging
Ursula Tuor1, Min Qiao2, Manasi Sule2, Qinbo Deng2, Melissa Morgunov2, David Rushforth2, and Tadeusz Foniok2
1Physiology and Pharmacology, Cl Neurosciences and Radiology, University of Calgary, Calgary, AB, Canada, 2University of Calgary, Calgary, AB, Canada

We investigated whether differing severities of photothrombotic insults could be produced in immature brain as observed in adult rats previously. Mild lesions in neonatal cortex consisted of small hyperintense DW regions corresponding to marked increases in T2. In contrast, adults had hyperintense DW regions corresponding to marked T2 increases but also modest T2 increases beyond the DW lesion border. In contrast to neonatal brain, T2 is more sensitive for detecting ischemic injury than DW in adult brain. The results indicate a promising approach to study thrombotic occlusion and reperfusion injury and its MR diagnosis using quantitative T2, DW and ADC.

2156.   Cerebrovascular damage after stroke in type two diabetic rats measured by MRI
Guangliang Ding1, Tao Yan1, Jieli Chen1, Michael Chopp1,2, Lian Li1, Qingjiang Li1, Chengcheng Cui1, Ruizhuo Ning1, and Quan Jiang1
1Neurology, Henry Ford Hospital, Detroit, Michigan, United States, 2Physics, Oakland University, Rochester, Michigan, United States

Using a suture 2h occlusion and reperfusion stroke model and a low dose Streptozotocin injection combined with a high fat food diet diabetic model of young adult Wistar rats, Gd-DTPA leakage measured by CE-T1WI indicates that T2DM rats suffered more severe BBB disruption from 1 to 5 weeks after stroke (p<0.005), and SWI identified significant larger hemorrhagic volumes in T2DM rats throughout 5w after stroke (p<0.05), compared with WT rats. FA values of ischemic boundary in the striatum were consistently lower in the T2DM rats than in the WT controls, which suggest that T2DM hampers axonal density increase.

2157.   Development of a Porcine Middle Cerebral Artery Occlusion Stroke Model and Stroke Characterization with Quantitative MRI Techniques.
Shannon P. Holmes1, Simon R. Platt2, Liya Wang3, Vivian Lau2, Grace Harrison2, Hui Mao3, and Franklin West2
1Veterinary Biosciences & Diagnostic Imaging, University of Georgia, Athens, GA, United States, 2University of Georgia, GA, United States, 3Emory University, GA, United States

Large animal models of stroke are needed for improved translation of novel therapeutics. The pig has been proposed as ideal, because of similar gyrification, gray-white matter composition and size to the human brain. This study developed a Landrace pig middle cerebral artery occlusion (MCAO) model. Anatomic and quantitative MRI techniques were used to evaluate the stroke, including DWI, spectroscopy, DTI and PWI. Anatomic studies, with DWI/ADC, measured the penumbra and ischemic zone. Significant differences were detected in neural metabolites and fractional anistrophy of white matter. Therefore, the Landrace pig MCAO model is feasible and produces in vivo quantifiable changes.

2158.   Assessment of neuroprotective effects of Neuregulin-1 on in acute stroke using diffusion MRI
Silun Wang1, Yonggang Li2, Ramesh Paudyal1, Byron D. Ford2, and Xiaodong Zhang1,3
1YERKES IMAGING CENTER, Emory University, Atlanta, GA, United States, 2Department of Neurobiology, Morehouse School of Medicine, GA, United States, 3Division of Neuropharmacology and Neurologic Diseases, Emory University, GA, United States

We evaluated the NRG-1 treatment response in a rat model of ischemic stroke using DTI. Results indicated that significantly lower infraction volume in the treatment group than in control group. Especially, it is shown the neuroprotective efficacy of NRG-1 is more evident in stroke rats with mild CBF reduction (<70% reduction). Significantly lower FA values were found in the vehicle group compared to NRG-1 treatment group, indicating less ischemic injury after NRG-1 administration. Our results support the use of DTI as a biomarker to non-invasively monitor the NRG-1 treatment response in ischemia induced brain injury.

2159.   Assessment of pharmacologically induced hypothermia in a rodent model of focal cerebral ischemia using diffusion tensor imaging
Silun Wang1, Xiaohuan Gu2, Ramesh Paudyal1, Shan Ping Yu2, and Xiaodong Zhang1,3
1YERKES IMAGING CENTER, Emory University, Atlanta, GA, United States, 2Department of Anesthesiology and Department of Neurology, Emory University School of Medicine, GA, United States, 3Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, GA, United States

We evaluated the pharmacologically induced hypothermia treatment response in focal cerebral ischemia induced brain injury in a mice model using DTI. Results indicated that significantly lower infraction volume in the treatment group than control group. Less reduction of ADC values were found in the hypothermia treatment group. Our results support the use of DTI as a biomarker to non-invasively monitor the hypothermia treatment response in ischemia induced brain injury.

2160.   Identification of 4-vessel occlusion in rat using MR angiography and 1H MRS at 14.1T
Mario G Lepore1, Corina Berset1, Rolf Gruetter2,3, and Hongxia Lei1,4
1AIT, Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 2Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 3University of Lausanne, Lausanne, Vaud, Switzerland, 4University of Geneva, Geneva, Geneva, Switzerland

We illustrated that MR angiography and 1H MRS can be applied to identity 4-vessel-occlusion in rat.

2161.   Absolute and Relative Blood Volume Measurements by dual T1 and T2 MRI acquisitions with single contrast agent in Acute Phase of Ischemic Brain
Ji-Yeon Suh1, Hoesu Jung2, Hyung Joon Cho2, Young Ro Kim3, Jeong Kon Kim4, and Gyunggoo Cho1
1Magnetic Resonance Research, Korea Basic Science Institute, Cheongju, Chungbuk, Korea, 2Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, Korea, 3Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Massachusetts, United States, 4Asan Medical Center University of Ulsan college of Medicine, Seoul, Korea

To study the altered cerebrovascular tones following focal or global cerebral ischemia, infrequently measuring changes in T2(*)-driven relative blood volumes have been performed. In the current study, using the concurrent T1-T2 effects of the exogenous contrast agent, dual contrasts acquisitions were established in the acute phase of rat ischemia model. Co-acquisitions of positive (T1) and negative (T2(*)) contrasts provide complementary information on neurovascular traits such as absolute and relative cerebral blood volume and microvascular volume. This work may supply an important basis for understanding the impaired cerebrovascular changes involved with ischemic damage.

2162.   MRI of a distal MCAO ischemic stroke lesion model in mice
Tom Dresselaers1, Annelies Quaegebeur2,3, Kristof Govaerts1, Inmaculada Segura2,3, Robin Lemmens4, Peter Carmeliet2,3, and Uwe Himmelreich1
1Dept. of Imaging and Pathology, KU Leuven, Leuven, Belgium, 2Vesalius Research Center, VIB, Belgium, 3KU Leuven, Leuven, Belgium, 4VIB, Belgium

In this study we characterized the stroke lesion in mice resulting from a permanent distal MCAO. At 2, 24h and 1 week post occlusion quantitative perfusion data based on pulsed ASL and ADC, T1 and T2 maps were recorded. Images were analyzed using either manual delineation or a threshold based approach with the contra-lateral cortex as a reference region. We demonstrate that lesion characterization via MRI in this distal MCAO mouse stroke model is feasible thereby opening up the possibility to non-invasively monitor stroke development in different transgenic animal models related to for example oxygen sensors or hypoxia.

2163.   Characterization of the ischemic penumbra using diffusion tensor MR imaging in a rat model of ischemic stroke treated with neuregulin-1
Silun Wang1, Yonggang Li2, Ramesh Paudyal1, Byron D. Ford2, and Xiaodong Zhang1
1YERKES IMAGING CENTER, Emory University, Atlanta, GA, United States, 2Department of Neurobiology, Morehouse School of Medicine, GA, United States

We have demonstrated that DTI indices could provide promise diagnostic information to evaluate white matter and grey matter injury in an rat model of ischemic stroke treated by Neuregulin 1 as well as to characterize the penumbra evolution after stroke onset. The severity of white matter and cortex injury are highly associated with the location of infarct and vascular territory. In addition, the neuroprotective effects could be in vivo monitored using DTI . NRG-1 seems to have significant neuroprotective effects to white matter and cortex especially in acute stroke.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2164.   Identifying Infarct Lesion using Diffusion Kurtosis Model with Multi-band EPI Sequence in Acute Ischemic Stroke Patients
Huan He1, Tianyi Qian2, Ni Liu1, Xingli Liu1, Zhongyan Wang1, Lu Su1, and Peiyi Gao1
1Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, Beijing, China, 2MR Collaborations NE Asia, Siemens Healthcare, Beijing, China

The key to thrombolytic therapy in acute ischemic stroke is identifying the areas of infarct lesion in acute stage. By using a prototype simultaneous multi-slice accelerated (SMS) EPI sequence for DKI data recording, the total acquisition time could be cut down to 1/2~1/3 of standard EPI-based DKI without losing SNR. In the identification of the final infarct size in acute ischemic stroke, the volume measurements by SMS DKI in the acute-phase is more reliable than that of ADC, and the DKI data could be acquired in a reasonable time with the SMS EPI sequence.

2165.   Fast and robust lesion detection and assessment in acute ischaemic stroke patients from ADC and quantitative T2 mapping
Michael John Knight1, Bryony McGarry1, Harriet Rogers1, Joanne Robson2, Rose Bosnell3, Philip Clatworthy1, and Risto Kauppinen1
1School of experimental psychology, University of Bristol, Bristol, avon, United Kingdom, 2Southmead Hospital, Bristol, avon, United Kingdom, 3School of clinical sciences, University of bristol, Bristol, avon, United Kingdom

This work presents a simple, yet robust means for identifying regions of acutely ischaemic tissue, with minimal human intervention, from ADC mapping, and for the assessment of that tissue based on quantitative T2 mapping in ischaemic stroke patients. Having identified ADC lesions(s), we show using T2 mapping that within ischaemia distinct tissue signatures with different relaxation charateristics are separated. In particular, whereas ADC and T2 are positively correlated in healthy tissue, this is not the case in in the ischaemia, which can act as a further restraint for distinguishing between different tissue states and lesion types.

2166.   Can diffusion weighted MR spectroscopy be used in differentiating acute MELAS and acute stroke?
Dandan Zheng1, Bing Wu1, Jiangxi Xiao2, Zhenghua Liu2, and Zhenyu Zhou1
1GE Healthcare China, Beijing, Beijing, China, 2Radiology Department, Peking University First Hospital, Beijing, China

The underlying mechanism of neurological symptoms in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is still controversial. Signal abnormalities in conventional MR contrast are indistinguishable from those observed in stroke, especially in the acute stage. In this study, diffusion weighted MR spectroscopy was used to differentiate acute MELAS from acute stroke and also to probe the mechanisms underlying the pathogenesis of MELAS.

2167.   Optimal T1-weighted MR plaque imaging for cervical carotid artery stenosis in predicting development of microembolic signals during carotid dissection in endarterectomy.
Yuiko Sato1, Kuniaki Ogasawara1, Shinsuke Narumi2, Makoto Sasaki3, Ayumi Saito2, Takamasa Namba1, Masakazu Kobayasi1, Kenji Yoshida1, Yasuo Terayama2, and Akira Ogawa1
1Department of Neurosurgery, Iwate Medical Univercity, Morioka, Iwate, Japan, 2Department of Neurology and Gerontology, Iwate Medical Univercity, Morioka, Iwate, Japan,3Division of Ultra-High Field MRI and Department of Radiology, Iwate Medical Univercity, Mrioka, Iwate, Japan

The purpose of the present study was to determine which plaque imaging technique predicts more accurately development of microembolic signals (MES) during carotid dissection in carotid endarterectomy (CEA). Our results demonstrated that non cardiac-gated spin echo (SE) T1-weighted plaque imaging, which discriminated the intraplaque characteristics with the contrast ratio of the plaque signal to the sternomastoid muscle signal and with the three component color-coded map, could predict more accurately development of MES during carotid dissection in CEA than other MR plaque imaging techniques (black-blood fast SE, MPRAGE, the source image of 3D-TOF MRA).

2168.   Regional quantifying normal-appearing white matter perfusion in mild to moderate hypertension using 3D pseudo-continous arterial spin labeling
Ting Wang1, Yanhua Li2, Xinhong Guo2, Diandian Huang1, Lin Ma1, and Xin Lou1
1Department of Radiology, Chinese PLA General Hospital, Beijing, Beijing, China, 2Department of Cardiology, Chinese PLA General Hospital, Beijing, Beijing, China

White matter (WM) is the predilection area of lacunar infarction in hypertensive patients. It was hypothesized that abnormal CBF in WM appeared at early stage of hypertension, hence, we recruited thirty hypertensive patients and thirty healthy controls of an appropriate age to detect their CBF modifications of normal-appearing WM using 3D pcASL technique. As expected, compare to healthy volunteers, CBF values in various WM regions were observed to be lower in hypertensive patients. This proves that 3D pCASL has ability to detect the subtle hemodynamic abnormalities even at the early stage of hypertension.

2169.   Small network properity changes in MCI with lacunar infraction
Wu Wenbo1, Yin Zhenyu1, Zhang Xin2, Zhou Fei2, Liu Renyuan1, Wang Huiting2, Zhu Bin2, Zhang Bing2, and Xu Yun1
1Neurology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China, 2Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu, China

In this abstract, we compared the small-world properties among the MCI patients with or without lacunar infraction and normal aging elderly by applying graph-theoretical analyses.

2170.   Validity of Three Dimensional Pseudo-Continuous Arterial Spin Labeling in Leptomeaningeal Collaterals Assessement for Patients with Unilateral Middle Cerebral Artery Stenosis
Jinhao Lyu1, Ning Ma2, Zhongrong Miao2, Lin Ma1, and Xin Lou1
1Department of Radiology, Chinese PLA General Hospital, Beijing, Beijing, China, 2Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, Beijing, China

Three dimensional pseudo-continuous arterial spin labeling(3D pCASL) is able to differentiate delay arrived blood flow form leptomeaningeal collaterals in patients with middle cerebral artery stenosis by applying multiple post labeling delay(PLD). We compared multi-PLD 3D pCASL with conventional angiography capillary index score(CIS) system in leptomeaningeal collaterals assessment.

2171.   Interstudy and intraobserver reproducibility of high-resolution MRI in evaluating basilar atherosclerotic plaque at 3Tesla
Luguang Chen1, Xia Tian1, Qi Liu1, Chao Ma1, Qian Zhan1, Xuefeng Zhang1, Yuanliang Jiang1, and Jianping Lu1
1Department of Radiology,Changhai Hospital of Shanghai, The Second Military Medical University, Shanghai, Shanghai, China

Intracranial artery atherosclerosis is increasingly being recognized as a major cause of stroke worldwide, and patients with intracranial steno-occlusive disease have an augmented risk of vascular events. Several imaging modalities, including digital subtraction angiography, computed tomography angiography, and magnetic resonance imaging (MRI), are used to assess intracranial atherosclerosis. However, dark blood high-resolution MRI (HRMRI) superiors to other techniques in delineating the wall of the basilar artery (BA) because it is noninvasive and radiation-free.To our knowledge, the scan and rescan reproducibility of quantification of BA plaque has not reported. Therefore, the purpose of the present study is to evaluate of the interscan and intraobserver reproducibility of BA plaque employing dark blood HRMRI at 3Tesla.

2172.   Plaque characteristics, burden and distribution assessment with high-resolution intracranial vessel wall imaging at 3 tesla MRI
Nikki Dieleman1, Wenjie Yang2, Jill Abrigo3, Ka Lok Lee3, Chiu Wing Chu3, Anja G. van der Kolk1, Jeroen C.W. Siero1, Ka Sing Wong2, Jeroen Hendrikse1, and Xiang Yan Chen2
1Department of Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Department of Medicine, Chinese University of Hong Kong, Shatin, Hong Kong, China, 3Department of Imaging and Interventional Radiology, Chinese University of Hong Kong, Shatin, Hong Kong, China

In this study we qualitatively evaluated intracranial plaque characteristics (contrast enhancement, thickening and configuration), total plaque burden and distribution in patients with an MCA stenosis using a 3D T1-weighted volumetric isotropic turbo spin-echo acquisition (VISTA) vessel wall sequence at 3 tesla. The sequence was able to identify basic intracranial plaque characteristics and assess total plaque burden and distribution. We demonstrate that intracranial atherosclerotic plaques are mainly associated with an eccentric configuration and a focal thickening pattern. Most of the lesions were found in the anterior circulation, corresponding to similar distributions found for ischemic strokes.

2173.   Prevalence of cerebrovascular reserve impairment in patients with severe intracranial arterial stenosis
Alexandre Krainik1, Olivier Heck2, Arnaud Attyé2, Naila Boudiaf3, Florence Tahon2, Kamel Boubagra2, Johan Pietras2, and Olivier Detante2
1Neuroradiology and MRI, University hospital of Grenoble, Grenoble, France, 2University hospital of Grenoble, France, 3LPNC, France

Management of patients with Severe Intracranial Arterial Stenosis (SIAS) at risk of stroke events recurrence remains controversial. A better characterization of these patients might be helpful to define therapeutic strategy. BOLD fMRI to hypercapnic challenge has been proposed to identify impaired cerebrovascular reserve (CVR BOLD fMRI). We conducted a prospective study in 35 patients referred for a SIAS to estimate CVR BOLD fMRI, and compared their data a 100 volunteers’ dataset. Eighteen patients out of 35 had significantly impaired CVR. Thus, CVR BOLD fMRI could be helpful to better select patients with SIAS for more invasive treatment.

2174.   Reduced visual cortex perfusion without volume loss in mild to moderate hypertension
Diandian Huang1, Xin Lou1, Lin Ma1, and Zhengyu Zhou2
1radiology, Chinese PLA General Hospital, Beijing, Beijing, China, 2MR Research Center, GE Health care, Beijing, China

Hypertensive group without retinopathy and control group were recruited from the primary care and had a MR scan with the three-dimensional pseudo-continuous arterial spin labeling (3D pCASL) and routine sequences. Compared to the control group, hypertensive patients implied the reduced CBF values on visual cortex without the statistical volume loss which may implicated there is a variety of the hemodynamics prior to the change of the morphology in the visual cortex in hypertension. Future studies in larger cohorts and longitudinal follow-up are needed to investigate the functional and prognostic significance of the early visual cortex perfusion deficits observed.

2175.   Cerebral Hemodynamics after Reduction of Blood Pressure in Hypertension Measured with 3D pCASL
Xin Lou1, Ning Ma2, Yanhua Li3, Diandian Huang1, Ting Wang1, Zhenyu Zhou4, Bing Wu4, and Lin Ma1
1Department of Radiology, Chinese PLA General Hospital, Beijing, China, 2Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China, 3Department of Cardiology, Chinese PLA General Hospital, Beijing, China, 4MR Research Center, GE Healthcare, Beijing, China

The treatment of hypertension with acute ischemic stroke is controversial due to decrease mean arterial pressure may reduce cerebral blood flow to already ischemic regions and result in further ischemic injury after intake of antihypertensive drugs. Our findings suggested that there is a rapid adaptation of the cerebral hemisphere and brain stem to antihypertensive therapy in order to protect those areas of the brain from hypoperfusion; however, an acute reduction in BP may compromise cerebellar perfusion at the initial stage of antihypertensive therapy in patients with hypertension. 3D pCASL can be used for monitoring cerebral blood flow during antihypertensive therapy.

2176.   Quantifying the effects of lesions with the Tractography-based Lesion Assessment Standard (TractLAS)
Christopher J. Steele1, Leonie Lampe1, Alexander Schaefer1,2, Alfred Anwander1, Bernhard Sehm1, and Arno Villringer1
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Sachsen, Germany, 2Department of Electrical and Computer Engineering, Clinical Imaging Research Centre & Singapore Insitu, Singapore, Singapore, Singapore

Current MRI techniques for assessing the impact of brain lesions consider only lesion location, type, and extent, while ignoring how the lesioned region was previously connected to the rest of the brain. To address this, we created a tractography-based network model describing normal white-matter connectivity in the human brain: the TractLAS. Individual patient lesions can be introduced into the model to quantify the effects of disconnection on the network, and relate them to behaviour and functional outcomes. This model helps to advance a network-based understanding of the functional effects of focal brain lesions.

2177.   Identification of neurovascular changes in cerebral amyloid angiopathy by modeling subject-specific hemodynamic response functions
Rebecca J Williams1,2, Bradley Goodyear1,2, Stefano Peca3, Cheryl R McCreary1,2, Richard Frayne1,2, Eric E Smith1,2, and G Bruce Pike1,2
1Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada, 2Seaman Family MR Research Centre, Alberta Health Services, Calgary, Alberta, Canada, 3Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta, Canada

Cerebral amyloid angiopathy (CAA) is an age-related disease affecting the small blood vessels. Vascular changes resulting from CAA have been detected using fMRI, however modelling the hemodynamic response function (HRF) may provide further information than BOLD signal amplitude alone. Here we characterized the HRF in CAA patients and healthy controls. Subject-specific HRFs were estimated using the sum of two gamma functions model. The time-to-peak (TTP) and full-width at half-maximum (FWHM) of the positive response were calculated from each subject's HRF and quantitatively compared between groups. We found that the FWHM may be a sensitive marker of CAA-related neurovascular changes.

2178.   Identifying Perfusion Deficits with Simultaneous Multi Slice Acceleration EPI Technique: A Non-Invasive Method
Tianyi Qian1, Zhigang Qi2, Mo Zhang2, Kun Zhou3, and Kuncheng Li2
1MR Collaborations NE Asia, Siemens Healthcare, Beijing, Beijing, China, 2Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China, 3Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China

Simultaneous Multi slice acceleration (SMS) EPI technique provides a new tool for measuring the DSC-MR and BOLD signal with higher spatial and/or temporal resolution. In this study, we applied an iterative algorithm to extract the global pattern by averaging the time series of each voxel after re-alignment based on its time-shift. In addition, by using SMS EPI sequence for rs-fMRI data acquisition, higher temporal resolution (TR = 1000 ms) and higher spatial resolution can be achieved to provide more accurate results.

2179.   Quantitative Evaluation of Collateral Perfusion Using Multi-delay 3D pCASL in Patients with Middle Cerebral Artery Stenosis
Xin Lou1, Ning Ma2, Jinghao Lyv1, Yang Xu1, Zhenyu Zhou3, Bing Wu3, and Lin Ma1
1Department of Radiology, Chinese PLA General Hospital, Beijing, China, 2Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China, 3MR Research Center, GE Healthcare, Beijing, China

DSA remains the method that can best evaluate collateral extents, but it is relatively time-consuming, invasive, costly, and cannot provide quantitative measurement. Determining the presence and adequacy of collateral blood flow is important in patients with severe intracranial stenosis or occlusion due to collateral flow can maintain cerebral circulation and may be another potential therapeutic target in acute ischemic stroke. Our study suggests that multi-post labeling delay time 3D pCASL technique may be a useful tool to quantitative the collateral perfusion in patients with intracranial arterial stenosis.

2180.   Monitoring pH and energy metabolim in subacute stroke using 31P and 1H MRSI
Ulrich Pilatus1, Johann-Philipp Zöllner2, Elke Hattingen1, and Oliver Singer2
1Neuroradiology, Goethe-University Frankfurt, Frankfurt, Germany, 2Neurology, Goethe-University Frankfurt, Germany

31P and 1H Magnetic resonance spectroscopic imaging (MRSI) was used to measure pH and energy metabolism in subacute stroke (mean of 6 days after stroke). We found two inorganic phosphate signals in stroke tissue, which indicates a fraction at alcalotic pH (7.38) and one at regular pH (7.03). High energy metabolites were decreased but not totally depleted.

2181.   Assessments of Oxygen Extraction Fraction in Canines with Internal Carotid Arteries Ligated on Both Sides
Peng Wu1, Feiyan Chang2, Sheng Xie2, and Hua Guo1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Department of Radiology, China–Japan Friendship Hospital, Beijing, China

Measurements of oxygen extraction fraction are of great importance in the study of brain metabolism. There are several MRI-based methods, this study shows the feasibility of the model proposed by Haccke and Yablonskiy. Six canines with internal carotid arteries ligated on both sides were studied. The data were acquired with ASE-EPI sequence and used to estimate OEF by fitting to the model proposed by Haccke and Yablonskiy. The results showed that the OEF values of these canines increased significantly (p=0.004) after the ligation. DWI images and triphenyl tetrazolium chloride stained sections were consistent with the estimated OEF maps.

2182.   Utility of Bi- and Stretched-Exponential Diffusion-Weighted MR Imaging Models Using High b-Values in Assessment of Stroke
Shiteng Suo1, Zengai Chen1, and Jianrong Xu1
1Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, China

The current study demonstrated the utility of bi- and stretched-exponential diffusion models in characterize the non-Gaussian diffusion behavior in acute/subacute stroke. The preliminary results suggest that the bi- and stretched -exponential model can help better describe the complex behavior of water diffusion in acute/subacute stroke, and may provide more detailed and useful metrics for lesion assessment and prognosis.

2183.   Prediction of the onset day using by T2*-weighted magnetic resonance imaging in patients with subarachnoid hemorrhage
Takashi Inoue1, Miki Fujimura2, Kuniyasu Niizuma2, and Teiji Tominaga2
1Neurosurgery, Sendai Medical Center, Sendai, Miyagi, Japan, 2Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan

Timing of the onset of subarachnoid hemorrhage (SAH) is important for treatment decision making, especially as some patients visit hospital several weeks after the onset of SAH. T2*-weighted (T2*W) magnetic resonance (MR) imaging is regarded as a sensitive method for the detection of deoxyhemoglobin or hemosiderin deposits. The abnormal low intensity on T2*W imaging gradually decreased until 90 days from the onset of SAH, but persisted 16 years after the onset. We could predict the day of onset with pure error }10 days in patients with SAH within 90 days of onset, using our grading system for T2*W images.

2184.   DKI manifestation in patients with acute ischemic stroke
Gang Guo1 and Liuhong Zhu1
1Radiology, Xiamen Second Hospital, Xiamen, Fujian, China

The performance of diffusion kurtosis imaging (DKI) in the analysis of micro-structural changes of brain tissue affected by acute ischemic stroke was explored. Seventy-two lesions in common affected locations were outlined in fifty-nine patients. Four types of DKI manifestation in acute ischemic stroke lesions were classified according to the changes of DKI signal intensity. Multiple comparisons among types indicated that DKI could stratify heterogeneous and microstructure changes within acute stroke DWI lesions.

2185.   The Influence of Clinical Confounders on Imaging Biomarkers of Lesion Age in Acute Stroke
Vince I Madai1, Carla N Wood1, Ivana Galinovic1, Ulrike Grittner1, Gajanan S Revankar1, Steve Z Martin1, Olivier Zaro Weber2, Walter Möller-Hartmann3, Federico C von Samson-Himmelstjerna1,4, Wolf-Dieter Heiss2, Martin Ebinger5, Jochen B Fiebach1, and Jan Sobesky1
1Center for Stroke Research Berlin, Charité Universitätsmedizin Berlin, Berlin, Berlin, Germany, 2Max Planck Institute for Metabolism Research, Cologne, Germany,3Department of Radiology, Ludmillenstift Meppen, Meppen, Germany, 4Fraunhofer MEVIS, Bremen, Germany, 5Centre for Stroke Research Berlin, Charité Universitätsmedizin Berlin, Berlin, Germany

In acute stroke of unknown onset, the DWI-FLAIR mismatch allows for the identification of patients presenting within the thrombolysis time window (<4.5h). FLAIR lesions, however, are difficult to analyze visually. Relative-signal-intensity (rSI) biomarkers derived from MRI sequences, namely DWI or FLAIR, constitute an increasingly investigated observer-independent alternative. In the present work we demonstrate that clinical confounders (e.g. age, NIHSS) significantly influence performance of FLAIR imaging biomarkers in contrast to DWI biomarkers, which are independent of this influence and offer high performance. These results might partly explain heteregenous results for FLAIR biomarkers in the past and support the use of DWI biomarkers.

2186.   Quantification of the local dynamic of the cerebrovascular autoregulation
Marco Piccirelli1, Bas van Niftrik2, Oliver Bozinov2, Athina Pangalu1, Antonios Valavanis1, Luca Regli2, and Jorn Fierstra2
1Neuroradiology University Hospital, Zurich, ZH, Switzerland, 2Neurosurgery University Hospital, Zurich, ZH, Switzerland

To quantify the local cerebrovascular autoregulation in function of the partial pressure of CO2 (PaCO2), we combined quantitative cerebral flow measurements obtained with ASL and cerebrovascular reactivity (CVR) with BOLD fMRI. To control for PaCO2, a prospective end tidal gas blender was used. This unique combination during a capnic challenge in healthy subjects and steno occlusive patients allows for the assessment of a quantitative CVR curve and deliver a multi-parametric map including cerebrovascular reactivity, reserve capacity and mean cerebral blood flow measurements during known hypocapnic and hypercapnic states.

2187.   Comparison of PWI, DWI, and clinical outcome for suspected stroke
Neil Chatterjee1, Shyam Prabhakaran2, Sameer Ansari1, and Timiothy Carroll1
1Radiology, Northwestern University, Chicago, IL, United States, 2Neurology, Northwestern University, Chicago, IL, United States

Fully automated methods were used to analyze perfusion weighted (PWI) and diffusion weighted (DWI) MR images in a cohort of 109 patients suspected of having a stroke or transient ischemic attack and compared to modified Rankin Scale (mRS) collected after 3 months. Compared to a referece group with an mRS of 0, we found that DWI measurements were only significantly different in patients with an mRS of 4, but PWI measurements were different across a greater range of mRS scores. This may indicate that PWI may be a better predictor for intermediate outcomes.

2188.   Susceptibility-weighted imaging of acute ischemic stroke: quantification of hypoperfusion
Hung-Wen Kao1,2, Yu-Chuan Chang3, Ching-Po Lin2,4, and Chien-Yuan Eddy Lin5,6
1Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, 2Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 3Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 4Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, 5GE Healthcare, Taipei, Taiwan, 6GE Healthcare China, Beijing, China

Susceptibility-weighted imaging (SWI) is very sensitive in detecting blood products and showing blood-oxygen-level dependent (BOLD) signal changes presumably from different concentrations of deoxygenated blood. Therefore, we hypothesize that SWI could provide oxygen metabolic information in relation to perfusion in patients with acute ischemic stroke. In our study, we compared area percentages of increased BOLD signal (IBS) in ROIs of restricted diffusion and perfusion defect. The results suggested a positive correlation between perfusion and IBS, a finding contradicting the implication of IBS as miserable perfusion and indicating a mismatch between perfusion and oxygen metabolism.

2189.   Longitudinal quantitative MRI Provides Quality Assurance Measures in Patients with Ischemic Stroke Treated with Autologous Bone Marrow Derived Mononuclear Cells.
Muhammad E Haque1, Khader M Hasan2, Benjamin A Schatz3, Sarah M Lund3, Farhaan S Vahidy4, and Sean I Savitz4
1Neurology, Unversity of Texas Health Science Center at Houston, Houston, TX, United States, 2Diagnostic and Interventional Imaging, Unversity of Texas Health Science Center at Houston, Houston, TX, United States, 3Unversity of Texas Health Science Center at Houston, TX, United States, 4Neurology, Unversity of Texas Health Science Center at Houston, TX, United States

Post stroke cell therapy may offer a promising regenerative therapy. There is a need to establish reliable neuroimaging markers to assure safety and help advance neubiological models. In this study we sought to present some quality assurance measures by testing the integrity of white matter fibers in the anterior and posterior corpus callosum regions post MCA stroke.

2190.   Amide proton transfer in detecting intracerebral hemorrhage
Xiaoyue Ma1, Panli Zuo2, Benjamin Schmitt3, Dapeng Shi4, Jinyuan Zhou5, and Meiyun Wang4
1Radiology, Zhengzhou University People¡¯s Hospital & Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China, 2Siemens Healthcare, MR Collaboration NE Asia, Beijing, China, 3Siemens Ltd Australia, Healthcare Sector, Macquarie Park, Australia, 4Radiology, Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China, 5Radiology, John Hopkins University, Baltimore, United States

Amide Proton Transfer (APT) is a kind of chemical exchange-dependent saturation transfer (CEST) imaging which can detect peptides and endogenous mobile proteins. We aimed to explore the value of non-invasive APT in early detecting intracerebral hemorrhage (ICH) at different stages by comparing it to susceptibility weighted imaging (SWI), the most sensitive tool for detecting ICH. Routine MRI, SWI and APT imaging were performed in 39 patients with ICH at different stages on a 3.0 T. The MRI findings were evaluated, the signal values of SWI and APT in the hemorrhage lesions were measured and compared with the contralateral normal brain tissue. Paired-sample t-test was used for statistical evaluation. SWI showed hypointense signal in 15 cases and heterogeneous signal intensity in the other 14 cases. However, all the ICH lesions were hyperintense on the APT-weighted images. Both the mean values of APT and SWI were higher in the hemorrhagic lesions than in the contralateral normal brain tissue (P<0.01). Routine MR imaging has limitation in detecting ICH because of the various signal intensities at the different stages. SWI is more sensitive than conventional MRIs in detecting ICH. But SWI shows heterogeneous signal intensity in half of the cases with ICH because of the T2 and T1 properties in SWI. As APT can detect endogenous mobile proteins and peptides, the ICH which contains many hemoglobins always shows hyperintensity on APT. In this way, APT imaging is sensitive to detect ICH and may provide a new MRI tool as a routine imaging technique for early detecting ICH. In this way, APT imaging is sensitive to detect ICH and may provide a new MRI tool as a routine imaging technique for early detecting ICH.

2191.   Characteristics of the Carotid Atherosclerotic Plaque Classified by NIHSS in Ischemic Stroke
Xiao Gao1, Shengzhang Ji1, Jinyu Song1, Xihai Zhao2, Haiman Bian1, Yu Zhang3, Yingyin Feng1, and Shengli Chen1
1The 4th center hospital of TianJin, TianJin, TianJin, China, 2Tsinghua University School of Medicine, Beijing, China, 3Philips Healthcare, Beijing, China

Investigate the relativity between vulnerable components and cerebral function by analyzing the plaque characteristics according to NIHSS score.

2192.   
An automated post-processing pipeline for the separation of intracranial and extracranial vessels in 7T TOF-MRA
Zihao Zhang1,2, Dehe Weng3, Jing An3, Zhentao Zuo1, Bo Wang1, Qingle Kong1, Ning Wei1,2, Yan Zhuo1, Xiaohong Joe Zhou4, and Rong Xue1
1State Key Lab of Brain and Cognitive Science, Beijing MR Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, Beijing, China, 2Graduate School, University of Chinese Academy of Sciences, Beijing, Beijing, China, 3Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong, China, 4Dept. of Radiology, Center for MR Research, University of Illinois, Chicago, Illinois, United States

An automated post-processing pipeline of TOF-MRA is proposed to separate intracranial and extracranial vessels, without the aid of T1w structural images. The post-processing uses nonlinear registration to produce ROIs in individual space. The pipeline was verified to provide clear MIP images of intracranial and extracranial vessels, respectively, which is useful in extra-intracranial bypass surgery.

2193.   
Semi-automated visualization and segmentation of cerebral veins from QSM
Suheyla Cetin1, Berkin Bilgic2, Audrey Peiwen Fan3, Kawin Setsompop2, and Gozde Unal1
1Faculty of Natural Sciences and Engineering, Sabanci University, Istanbul, Istanbul, Turkey, 2Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 3Department of Radiology, Stanford University, CA, United States

Susceptibility MRI provides contrast of the brain’s venous vasculature due to the presence of paramagnetic deoxyhemoglobin molecules in cerebral veins. Although susceptibility-weighted imaging has gained popularity to image veins in clinical applications such as stroke and traumatic brain injury, this method suffers from non-local and orientation-dependent effects that may prevent accurate identification of brain vessels. The purpose of our study is to demonstrate visualization and segmentation of cerebral veins from quantitative susceptibility maps (QSMs), a new MRI contrast reconstructed from phase images.

2194.   EPT - Measurement of Brain Conductivity for Non-oncologic Applications
Monika Huhndorf1, Christian Stehning2, Axel Rohr1, Michael Helle2, Thomas Stehle2, Ulrich Katscher2, and Olav Jansen1
1Clinic for Radiology and Neuroradiology, Kiel, Germany, 2Philips Research Europe, Hamburg, Germany

Imaging electric conductivity of tissue with Electric Properties Tomography (EPT) has been introduced first in 2009. Since then it has been used in several studies characterising brain tumors, especially gliomas, showing that EPT is able to distinguish between WHO grade IV gliomas and grade I-III. In this study we tested EPT on different neuroradiologic diagnoses to get an idea which other central nervous system diseases might benefit using conductivity as additional diagnostic parameter. It turned out that EPT has also potential to detect changes in brain tissue due to, e.g., microangiopathy, stroke, and multiple sclerosis.

2195.   Measuring the Timing Information of Blood Flow in Acute Stroke with the "Background Noise" of BOLD Signal
Tianyi Qian1, Zhongyan Wang2, and Peiyi Gao2
1MR Collaborations NE Asia, Siemens Healthcare, Beijing, Beijing, China, 2Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, Beijing, China

Low-frequencie fluctuation in the range of 0.01¨C0.1 Hz is commonly observed in BOLD signal and has been widely used for analyzing brain functional activation patterns. In this study, an iterative algorithm was used to extract the time-shift-corrected time series pattern of whole-brain BOLD signal. The iterative algorithm for computing the global template of the time series pattern is able to increase the estimation performance significantly while reducing the amount of required rs-fMRI data; shortening the examination time, which is of great importance for potential future clinical applications.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2196.   High-resolution Neurite Orientation Dispersion and Density Imaging in the substantia nigra of de novo Parkinson disease
Koji Kamagata1, Masaaki Hori1, Akira Nishikori2, Kohei Tsuruta2, Ayami Okuzumi3, Taku Hatano3, Kouhei Kamiya4, Nobutaka Hattori3, and Shigeki Aoki1
1Department of Radiology, Juntendo University, Tokyo, Bunkyo-ku, Japan, 2Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Hachioji-shi, Japan,3Department of Neurology, Juntendo University, Tokyo, Bunkyo-ku, Japan, 4Department of Radiology, the University of Tokyo, Tokyo, Bunkyo-ku, Japan

High-resolution NODDI analysis provides a result that likely reflects a decrease of dendritic length and loss of dendritic spines in the SNpc, consistent with prior pathological research. Because Vic and OD were significantly correlated with disease duration and UPDRS-3, NODDI could become a useful tool for assessing disease progression of PD.

2197.   Brain iron accumulation in Wilson disease: a pilot 7T MR-histopathology correlation study
Petr Dusek1,2, Erik Bahn3, Tomasz Litwin4, Christiane Wegner3, Vince Istvan Madai5, Matthias Dieringer6,7, Till Huelnhagen6, Michael Knauth1, Thoralf Niendorf6,7, Jan Sobesky5,7, Anna Czlonkowska4,8, Wolfgang Brueck3, Friedemann Paul9, Susanne A Schneider10, and Jens Wuerfel1,9
1Institute of Neuroradiology, University Medicine Goettingen, Goettingen, Germany, 2Department of Neurology and Center of Clinical Neuroscience, 1st Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic, 3Institute of Neuropathology, University Medicine Goettingen, Goettingen, Germany, 42nd Department of Neurology, Institute Psychiatry and Neurology, Warsaw, Poland, 5Department of Neurology and Center for Stroke Research Berlin (CSB), Charité-Universitaetsmedizin, Berlin, Germany, 6Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, 7Experimental and Clinical Research Center (ECRC), Charité-Universitaetsmedizin and Max Delbrueck Center for Molecular Medicine (MDC), Berlin, Germany, 8Department of Experimental and Clinical Pharmacology, Medical University, Warsaw, Poland, 9NeuroCure Clinical Research Center, Charité-Universitaetsmedizin, Berlin, Germany, 10Neurology Department, University of Kiel, Kiel, Germany

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2198.   Diffusion kurtosis imaging detects microstructural alterations in brain of α-synuclein overexpressing transgenic mouse model of Parkinson’s disease: a pilot study
Peter Latta1, Amit Khairnar1, Eva Drazanova2, Jana Kucerova1, Anas Arab1, Birgit Hutter-Paier3, Daniel Havas3, Manfred Windisch4, Zenon Starcuk Jr.2, Boguslaw Tomanek1,5, and Irena Rektorova1
1Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 2Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Brno, Czech Republic, 3QPS Austria GmbH, Graz, Austria, 4NeuroScios GmbH, Graz, Austria, 5University of Alberta, Edmonton, Alberta, Canada

Background: Accumulation and aggregation of α-synuclein contribute to the pathogenesis of Parkinson’s disease (PD). Our aim was to evaluate whether diffusion kurtosis imaging (DKI) will help to differentiate between α-synuclein overexpressing transgenic mouse model of PD (TNWT-61) and wild-type (WT) littermates. Methods: TNWT-61 mice and WT littermates (9 month) underwent behavioral tests and MRI scanning using 9.4 Tesla system in vivo. Results: TNWT-61 mice showed significant motor impairment. Mean and radial diffusion kurtosis were significantly elevated in the TNWT-61 compared to WT Conclusions: The current study provides evidence that DKI might become a candidate diagnostic biomarker with translational potential.

2199.   Application of GluCEST MRI in Detection of Epileptogenic Foci in Temporal Lobe Epilepsy
Ravi Prakash Reddy Nanga1, Kathryn A. Davis2, Sandhitsu Das3, Stephanie H. Chen2, Peter Hadar2, Timothy H. Lucas4, Brian Litt2, John A. Detre2, Hari Hariharan1, Mark A. Elliott1, and Ravinder Reddy1
1Radiology, University of Pennsylvania Health Systems, Philadelphia, Pennsylvania, United States, 2Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 3Penn Image Computing & Science Lab, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 4Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, United States

Glutamate is widely thought to be central to epileptogenesis. Here we apply a novel noninvasive glutamate imaging technique, GluCEST (Glutamate Chemical Exchange Saturation Transfer) MRI at 7T with an aim to identify seizure foci with finer precision and higher sensitivity than currently used imaging modalities in subjects with Temporal Lobe Epilepsy (TLE).

2200.   Reduced Neurite Density in Pre-manifest Huntington’s Disease Population detected by NODDI
Jiaying Zhang1, Rachael I Scahill2, Alexandra Durr3, Blair Leavitt4, Raymund Roos5, Sarah J Tabrizi2, and Hui Zhang1
1Department of Computer Science and Centre for Medical Image Computing, UCL, London, United Kingdom, 2Institute of Neurology, UCL, London, United Kingdom, 3Department of Genetics and Cytogenetics, INSERM UMR S679, APHP Hôpital de la Salpêtrière, Paris, France, 4Department of Medical Genetics, University of British Columbia, British Columbia, Canada, 5Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands

The early detection of microstructural abnormalities in pre-manifest Huntington’s disease (pre-HD) population is important for the development of suitable biomarkers for clinical trials as well as inform future therapeutic strategy. Although tissue microstructure has traditionally been quantified with DTI, more advanced techniques such as NODDI are now available which may provide more specific measures. This study tests this hypothesis in pre-HD. We find that, compared to DTI, NODDI findings are not only more specific, revealing widespread reductions in neurite density, but also more sensitive, detecting more extensive and more statistically significant differences.

2201.   The abnormality of functional connectivity in Parkinson’s in dopaminergic regions
Yue Xing1, Stefan Schwarz1, Nin Bajaj2, Penny Gowland3, and Dorothee Auer1
1Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Division of Neurology, Nottingham University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom, 3Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

Differential functional connectivity patterns of anterior substantial nigra and posterior substantial nigra in Parkinson’s were identified by comparing with age- and sex-matched healthy volunteers with seed-based analysis on cross-scanner resting state fMRI data. This abnormal functional connectivity reduction of the anterior and posterior substantial nigra in Parkinson’s may suggest a link between posterior default-mode network impairment and dopaminergic deficit.

2202.   Diffusion Changes in the Medulla Oblongata in Parkinson Disease
Nadya Pyatigorskaya1,2, Romain Valabregue1,3, Cyril Poupon4, Marie Vidailhet3,5, and Stephane Lehericy1,2
1Centre de NeuroImagerie de Recherche – CENIR, Institut du Cerveau et de la Moelle épinière – ICM, Paris, France, 2Department of Neuroradiology, Hôpital Pitie-Salpetriere, Paris, France, 3Université Pierre et Marie Curie and Inserm UMR-S1127; CNRS, UMR 7225, Institut du Cerveau et de la Moelle épinière – ICM, Paris, France, 4NeuroSpin, CEA, Saclay, France, 5Federation de Neurologie, Hôpital Pitie-Salpetriere, Paris, France

 
According to Braak's model, the medulla oblongata and posterior pontine region may be affected early in the course of Parkinson Disease. Therefore, the aim of the present study was to characterize medulla oblongata damage using diffusion tensor imaging (DTI) in PD patients as compared with healthy volunteers. Increased diffusivity was observed in both medulla oblongata and pontine tegmentum. Longitudinal progression of diffusion changes in the medulla oblongata of PD patients and correlations with measures of autonomic dysfunction are currently being investigated

2203.   Odor-related Functional Deficits in the Primary Olfactory Cortex in Early-stage Parkinson's Disease
Jianli Wang1, Thyagarajan Subramanian2,3, Zachary Mosher1, Jeffrey Vesek1, and Qing X Yang1,4
1Radiology, Penn State College of Medicine, Hershey, Pennsylvania, United States, 2Neurology, Penn State College of Medicine, Hershey, Pennsylvania, United States, 3Neural & Behavioral Sciences, Penn State College of Medicine, Hershey, Pennsylvania, United States, 4Neurosurgery, Penn State College of Medicine, Hershey, Pennsylvania, United States

The central olfactory system is highly affected by PD pathology and olfactory dysfunction is prevalent in Parkinson's disease (PD). With a sniffing-odor stimulation fMRI paradigm, we demonstrated significant reduced odor-induced activation in the primary and secondary olfactory cortex of early-stage PD patients compared to the healthy controls. The observed POC dysfunction was consistent with the impairment of smell identification function detected by the psychophysical test. Conversely, the sniffing function in the POC was less affected at the early stage of disease. In conclusion, olfactory deficits in the early-stage PD are dominantly odor-related.

2204.   Abnormalities in the Visual System of Streptozotocin-induced Type 1 Diabetic Rats-A Diffusion Tensor Imaging Study
Lifeng Gao1, Mingming Huang2, Fuchun Lin1, and Hao Lei1
1State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, China, 2Department of Radiology Affiliated Hospital of Guiyang Medical University, Guiyang, Guizhou, China

Type 1 diabetes was induced in rats by a single injection of streptozotocin (STZ). Diffusion tensor imaging on the visual system were performed at 12 weeks on a 7 T scanner to monitor the microstructure abnormalities induced by diabetes. Fractional anisotropy (FA), axial diffusivity (ADC||) and radial diffusivity (ADC¡Í) in the optic tracts and visual cortex were measured. Compared to the control animals, the STZ-treated rats showed significantly reduced FA in both the optic tracts and visual cortex at 12 weeks after diabetes induction. Correspondingly, significantly decreased ADC|| and significantly increased ADC¡Í were associated with hyperglycemia. The VC in the diabetic rats had a slight decline in ADC||, and a slight increase in ADC¡Í relative to those in controls.

2205.   Diffusion MRI of the spinal cord allows in vivo early detection and monitoring of GM and WM degeneration in a murine ALS model
Ileana Zucca1, Matteo Figini1, Alessandro Scotti1, Stefania Marcuzzo2, Silvia Bonanno2, Victoria Moreno Manzano3, José Manuel Garcia Verdugo4, Pia Bernasconi2, Renato Mantegazza2, and Maria Grazia Bruzzone5
1Scientific Direction, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Milan, Italy, 2Neurology IV - Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy, 3Neuronal and Tissue Regeneration laboratory, Centro de Investigación Príncipe Felipe, Valencia, Spain, 4Unidad de Neurobiología comparada, Universidad de Valencia, Valencia, Spain, 5Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy

The aim of this work was to investigate the potential of in vivo DTI parameters to detect WM and GM degeneration in the G93A-SOD1 mouse model of Amyotrophic lateral sclerosis (ALS). 7 G93A-SOD1 mice and 7 WT-SOD1 mice were followed at multiple time points (9, 10, 12, 15 and 17 weeks of age) with a DTI protocol on a 7T MRI scanner. DTI parameters, in particular AD in WM and MD in GM, highlighted very early alterations especially in ventral regions, confirmed by histology and electron microscopy. DTI parameters may therefore be early in vivo biomarkers of neurodegeneration in ALS.

2206.   Imaging dopamine autoreceptor activity using functional MRI as a novel technique in Parkinson¡¦s disease
Chiao-Chi V Chen1, Yi-Hua Hsu1, Chien-Yuan E Lin2,3, and Chen Chang1
1Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, 2GE Healthcare, Taipei, Taiwan, 3MR Advanced Application and Research Center, GE Healthcare, China

Imaging of dopamine autoreceptor activity is a brand new concept. We took advantage of our recently established noxiousness-evoked functional magnetic resonance imaging (fMRI) paradigm for developing such technique. This enables us to gain understanding about how D2 autoreceptor is affected in PD.

2207.   Microstructural Changes of Short Association Fibers in Parkinson's Disease and Normal Aging Assessed by Diffusion Tensor Imaging.
Jan Sedlacik1, Jan-Rüdiger Schüre1,2, Kai Boelmans3, and Jens Fiehler1
1University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 2Technical University of Ilmenau, Thüringen, Germany, 3University Hospital of Würzburg, Bayern, Germany

Frontal and central short association fibers (U-fibers) were investigated by Diffusion Tensor Imaging (DTI) in Parkinson's disease (PD) and healthy subjects. Healthy age-related DTI changes were found in control subjects. In detail, axial (AD), radial (RD) and mean diffusivity (MD) increased in frontal and central fibers and fractional anisotropy (FA) decreased in frontal but increased in central fibers. Age matched healthy controls showed slightly lower AD/RD/MD and higher FA as compared to PD patients, which may suggest only a marginal microstructural degeneration of U-fibers in PD patients.

2208.   Pathological Differences in Neuromyelitis Optica Reflected Differently by Two Myelin Water Imaging Techniques
Shannon Kolind1, Praveena Manogaran1, Irene Vavasour2, Bretta Russell-Schulz2, Katrina McMullen1, Jing Zhang2, Cornelia Laule2,3, Alexander MacKay2,4, Alexander Rauscher2, David Li2, and Anthony Traboulsee1
1Medicine, University of British Columbia, Vancouver, BC, Canada, 2Radiology, University of British Columbia, Vancouver, BC, Canada, 3Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, 4Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada

Neuromyelitis optica (NMO), while similar to multiple sclerosis (MS), has a different mechanism for demyelination and primarily affects the optic nerve and spinal cord. We measured myelin water fraction using a multi-echo GRASE approach (MWF) as well as mcDESPOT (fM) in the optic radiations and corticospinal tract (hypothesized to be demyelinated due to NMO’s primary optic nerve and spinal cord involvement), and the corpus callosum (hypothesized to be unaffected). MWF was reduced in NMO optic radiations and corticospinal tract but not corpus callosum. Contrary to MS findings, fM was not reduced in any region. This finding highlights how differences in pathology are reflected by each approach.

2209.   MRS of Basal-Ganglia in Parkinson’s Disease Reveals Higher GABA Levels
Shalmali Dharmadhikari1,2, Ruoyun Ma1,2, Chien- Lin Yeh1,2, Sandy Snyder1, S E Zauber3, and Ulrike Dydak1,2
1School of Health Sciences, Purdue University, W Lafayette, IN, United States, 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, United States

Gamma-aminobutyric acid (GABA) is an important inhibitory neurotransmitter of the basal ganglia, which is hypothesized to be altered in Parkinson’s disease (PD). Our aim was to evaluate the use of GABA MRS for understanding these alterations and their relation to disease severity, while reducing influence of PD medicines. GABA MRS in PD patients, who were temporarily withheld medication, revealed elevated GABA levels in the thalamus, which were also associated with disease severity as measured clinically by motor scores. Thus GABA MRS confirms the role of GABA in PD and has a potential to be used a non-invasive biomarker of PD.

2210.   Comparative study of anatomical connectivity of prelemniscal radiations in healthy subjects and Parkinson´s disease patients
Maria Guadalupe García-Gomar1, Francisco Velasco2, and Luis Concha1
1Universidad Nacional Autonoma de Mexico, Santiago de Queretaro, Queretaro, Mexico, 2Hospital General de Mexico, Distrito Federal, Mexico

Synopsis: Prelemniscal radiations (Raprl) are an exquisite neurosurgical target for treatment of tremor and rigidity. Despite its clinical relevance nowadays it remains unknown the anatomical connectivity of this area. Using diffusion MRI and probabilistic tractography we reconstructed different pathways passing trough the Raprl in healthy subjects and Parkinson´s disease patients. We compared the number of streamlines of both groups. Raprl tractography showed connections with motor and premotor cortex, globus pallidus (GP), thalamus, cerebellum and brainstem, having statistical differences between groups in tracts associated to GP and thalamus. Our findings provide new insights into subthalamic anatomic connectivity useful for neurosurgical procedures.

2211.   High resolution MR elastography reveals retrograde thalamic tissue degradation in Neuromyelitis optica
Kaspar-Josche Streitberger1,2, Andreas Fehlner1, Friedemann Paul3,4, Jens Würfel3,5, Jing Guo1, Jürgen Braun6, and Ingolf Sack1
1Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 2Department of Neurology with experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 3NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany, 4Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 5Institute of Neuroradiology, Universitätsmedizin Göttingen, Göttingen, Germany, 6Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany

High resolution multifrequency MR elastography was applied to patients with Neuromyelitis optica (NMO) – a disease which is characterized by recurrent inflammation and demyelination of the spinal cord and the optical nerves. Our hypothesis was based on reports on the sensitivity of viscoelastic parameters to neuroinflammation and neurodegradation. Consistently, high-resolution maps of the magnitude of the complex shear modulus revealed disseminated softening of cerebral tissue with marked effects on thalamus and white matter. The present study supports the hypothesis of a widespread cerebral neurodegeneraration in NMO and provides further details about regional effects of the disease.

2212.   Maximizing Tissue Contrast For MRI Evaluation of Parkinson’s Disease
Silvia Mangia1, Philip Burton1, Igor Nestrail1, Mikko Nissi1,2, Alejandra Sierra3, Karin Shmueli4, Michael Howell5, Paul Tuite5, and Shalom Michaeli1
1CMRR, University of Minnesota, Minneapolis, Minnesota, United States, 2University of Oulu, Oulu, Finland, 3A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland, 4University College London, London, United Kingdom, 5Department of Neurology, University of Minnesota, Minneapolis, Minnesota, United States

The findings of this preliminary study support the use of advanced MRI methods based on adiabatic T1ρ, T2ρ RAFF4, QSM, DTI and rsfMRI to characterize the microstructural integrity and functional connectivity of Parkinson’s disease (PD) subjects compared to healthy controls. Ultimately these methods may prove useful as a means to track the course of PD and potentially monitor the response to therapies.

2213.   Decreased Apparent Fibre Density in the optic pathways correlates with Glaucoma disease severity
David Raffelt1, Farnoosh Sadeghian1, Heather Connor2, and Alan Connelly1,3
1Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia, 2Department of Optometry, Deakin University, Melbourne, VIC, Australia, 3The Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia

Glaucoma is the second leading cause of blindness worldwide with 8.4 million bilaterally blind people. White matter abnormalities have been reported previously in Glaucoma using the diffusion tensor, however these results are difficult to interpret in regions with crossing fibres. In this study we investigate Glaucoma disease using Apparent Fibre Density (AFD), a quantitative measure that is tract specific, even in voxels with multiple fibres. When compared to healthy controls, we observed a decrease in AFD in the optic tract and radiation. Within these tracts we also observed significant AFD correlations with clinical measures of disease severity.

2214.   Whole-Brain Metabolic Profiling of Patients with Parkinson's Disease Using High-Resolution MR Spectroscopic Imaging
Mohammad Sabati, PhD1 and Sasha Raju, MBBS2
1Radiology, University of Miami, Miami, Florida, United States, 2Public Health Program, University of Miami, Miami, Florida, United States

Metabolite concentrations in 47 atlas-defined brain structures of 12 PD patients and 24 age- and gender-matched normal subjects were measured by using a sub-milliliter high-resolution whole-brain MR spectroscopic imaging (MRSI). The distributions as well as the statistically significant alterations of the measured metabolites NAA, Cho, and Cre were regional dependent. The results also indicate that the severity of PD, as measured by motor score, is correlated with the NAA and Cho/NAA in a number of the atlas-defined regions.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2215.   Gadolinium-enhanced magnetic susceptibility contrast is reduced in the corpus callosum of a mouse model of Tauopathy
James O'Callaghan1, Holly Holmes1, Nicholas Powell1, Ozama Ismail1, Niall Colgan1, Jack Wells1, Bernard Siow1, Michael O'Neill2, Emily Collins3, Karin Shmueli4, and Mark Lythgoe1
1Centre for Advanced Biomedical Imaging, University College London, London, Greater London, United Kingdom, 2Eli Lilly & Co. Ltd, Windlesham, Surrey, United Kingdom, 3Eli Lilly and Company, Indianapolis, United States, 4Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom

Alterations to white matter have been implicated in a number of neurodegenerative diseases. In this work we investigate the sensitivity of MRI magnetic susceptibility mapping to these changes using a mouse model of Tauopathy. A non-rigid registration of contrast enhanced, high resolution ex vivo mouse brain images is used to transform susceptibility maps into a common space and a voxel-wise group comparison is performed. Significant differences were observed that may indicate disruption to the tissue of the corpus callosum.

2216.   
Longitudinal whole-brain atrophy measurement in a mouse model of tauopathy using the Generalised Boundary Shift Integral
Nick M Powell1,2, Da Ma1,2, Ferran Prados1, Marc Modat1, Jorge Cardoso1, Holly E Holmes2, Ozama Ismail2, Niall Colgan2, Michael O'Neill3, Emily Collins4, Mark F Lythgoe2, and Sebastien Ourselin1
1Centre for Medical Image Computing, University College London, London, England, United Kingdom, 2Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 3Eli Lilly & Co. Ltd, Windlesham, Surrey, United Kingdom, 4Eli Lilly and Company, Indianapolis, IN, United States

We have for the first time applied the Boundary Shift Integral (BSI), a sensitive measure of atrophy, to structural MR images of a non-human animal: the rTG4510 mouse model of tauopathy. We measured rates of longitudinal atrophy equivalent to over 1% brain volume loss in just 30 days, and compared this to rates of brain volume change in wild-type littermate controls. The measure will be applied to a large cohort of over 200 scans, and shows promise as an early outcome measure for preclinical drug trials.

2217.   Quantitative magnetization transfer characteristics of white matter tracts correlates with DTI indices in predicting the conversion from mild cognitive impairment to Alzheimer’s disease
Elena Makovac1, Barbara Spano'1, Giovanni Giulietti1, Laura Serra1, Carlo Caltagirone2,3, Marco Bozzali1, and Mara Cercignani1,4
1Neuroimaging laboratory, IRCCS Santa Lucia Foundation, Roma, Italy, Italy, 2Department of Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, Roma, Italy, Italy, 3Department of Neuroscience, University of Rome ‘Tor Vergata’, Roma, Italy, Italy, 4Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, Sussex, United Kingdom

Patients with amnestic mild cognitive impairment (aMCI) have a higher risk of conversion to AD than healthy elderly subjects. We used probabilistic tractography to perform a multiparametric comparison of diffusion tensor imaging (DTI) and quantitative magnetization transfer (qMT) indices of the principal WM tracts involved by AD pathology between aMCI converting to AD and those who did not. Subtle changes in brain structure associated were more evident in aMCI converters than MCI non converters. RMB0 values correlated with of RDif of in almost all tracts suggesting that the two parameters might reflect similar properties of WM.

2218.   Divergent episodic memory networks among APOE alleles in cognitively normal elderly
Hao Shu1,2, Yongmei Shi1, Gang Chen2, Zan Wang1, Duan Liu1, Chunxian Yue1, B.Douglas Ward2, Wenjun Li2, Zhan Xu2, Guangyu Chen2, Qihao Guo3, Jun Xu4, Shi-Jiang Li2, and Zhijun Zhang1
1Department of Neurology, Affiliated ZhongDa Hospital, Neuropsychiatric Institute and Medical School of Southeast University, Nanjing, Jiangsu, China, 2Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States, 3Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China, 4Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, China

The apoliprotein E (APOE) ε4 allele is a risk factor and the ε2 allele is a protective factor for elderly episodic memory (EM) deterioration. However, neural bases linking APOE alleles and EM function remain unclear. This study voxelwisely correlated the hippocampal functional connectivity strength and EM score. It demonstrated the divergence of hippocampal-related network among the three APOE alleles in the cognitively normal elderly subjects, which may contribute to the APOE polymorphism effects on brain activation and associated with their different AD risks.

2219.   Evaluation of Two Susceptibility-Weighted Sequences for Detection of Cerebral Microbleeds
Cheryl R McCreary1,2, M Louis Lauzon1,2, Saima Batool1,2, Eric E Smith1,2, and Richard Frayne1,2
1Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada, 2Seaman Family MR Centre, Foothills Medical Centre, Calgary, Alberta, Canada

Quantitative susceptibility mapping (QSM) is a method that can be used to identify iron accumulation in the brain, which is a potential marker of neurodegeneration in aging. In an ongoing longitudinal study, susceptibility weighted imaging (SWI) is used for the identification of cerebral microbleeds (CMBs). In this study, we evaluate cerebral microbleed (CMB) detection on susceptibility-weighted images and images from single-echo data (SWI6e) collected from a multi-echo spoiled gradient echo sequence that can be used for quantitative susceptibility mapping. The CMB contrast was lower and the number of CMBs detected was underestimated in SWI6e images compared to SWI.

2220.   Brain plasticity in mild Alzheimer’s Disease. Effects of a computer-based cognitive training on functional connectivity
Francesco Barban1, Laura Serra2, Roberta Perri3, Roberta Annicchiarico3, Giovanni Augusto Carlesimo3,4, Matteo Mancini5, Fulvia Adriano3, Claudia Ricci3, Maria Giovanna Lombardi3, Mara Cercignani6, Lucia Fadda3,4, Carlo Caltagirone3,4, and Marco Bozzali2
1Clinical and Behavioral Neurology Laboratory; Neuroimaging Laboratory, IRCCS S Lucia Foundation, Rome, Rome, Italy, 2Neuroimaging Laboratory, IRCCS S Lucia Foundation, Rome, Rome, Italy, 3Clinical and Behavioral Neurology Laboratory, IRCCS S Lucia Foundation, Rome, Rome, Italy, 4Department of Neuroscience, University of Rome "Tor Vergata", Rome, Rome, Italy, 5Department of Engineering, University of Rome “Roma Tre”, Rome, Rome, Italy, 6Brighton & Sussex Medical School, Clinical Imaging Sciences Centre, University of Sussex, Brighton, Sussex, United Kingdom

The aim of this study was to investigate, with resting state-fMRI, the effects of a computerized cognitive training vs. an active placebo condition on brain networks of 19 mild Alzheimer’s Disease (mAD) patients with a cross-over design. Comparing pre-post training and placebo connectivity matrices, based on the Automated Anatomical Labelling atlas, with Network-Based Statistics, we found no placebo-related changes, whereas during training emerged a significant increased connectivity in brain regions crucial for memory and decreased connectivity in regions probably mediating compensational processes. We show for the first time a of functional connectivity reorganization in mAD after cognitive training.

2221.   A multi-scale MRI approach to investigate novel drug treatment strategies in mouse models of Alzheimer's disease
Holly Elizabeth Holmes1, Niall Colgan1, Ozama Ismail1, Da Ma2,3, Jack Wells1, Nicholas Powell1,3, James O'Callaghan1, Ian Harrison1, Manuel Jorge Cardoso3, Marc Modat2, Elizabeth MC Fisher4, Sebastian Ourselin3, Michael O'Neill5, Emily Catherine Collins6, and Mark F Lythgoe2
1Centre for Advanced Biomedical Imaging, University College London, London, Greater London, United Kingdom, 2University College London, London, Greater London, United Kingdom, 3Centre for Medical Image Computing, University College London, London, Greater London, United Kingdom, 4Department of Neurodegenerative Diseases, University College London, London, Greater London, United Kingdom, 5Eli Lilly & Co. Ltd, Windlesham, Surrey, United Kingdom, 6Eli Lilly & Company, Indianapolis, United States

A multi-scale MRI approach has been employed to characterise the rTg4510 mouse model of Alzheimer's disease, following early- and late-stage therapeutic intervention

2222.   For measuring hippocampal atrophy rates the boundary shift integral algorithm is substantially more accurate than FreeSurfer, manual, AdaBoost and FSL/First
Keith S Cover1, Ronald A van Schijndel1, Adriaan Versteeg1, Kelvin K Leung2, Emma R Mulder1, Remko A de Jong1, Peter J Visser1, Alberto Redolfi3, Jerome Revillard4, Baptiste Grenier4, David Manset4, Soheil Damangir5, Hugo Vrenken1, Bob W van Dijk1, Nick C Fox2, Giovanni Frisoni3, and Frederik Barkhof1
1VU University Medical Center, Amsterdam, North Holland, Netherlands, 2University College London, London, United Kingdom, 3IRCCS San Giovanni di Dio Fatebenefratelli, Italy, 4MAAT, Archamps, France, 5Karolinska Institutet, Sweden

To double check a recent reproducibility study that showed the boundary shift algorithm (BSI) is at least 70% more reproducible than the FreeSurfer/ReconAll, manual, AdaBoost and FSL/FIRST methods for measuring hippocampal atrophy rates. A novel statistical test of accuracy was employed based on the accepted hypothesis that, in older subjects, the hippocampus shrinks over time. The 4 other algorithms were found to require sample sizes at least 50% larger than BSI to reject the null hypothesis. The novel statistical test employed provides double check of superior reproducibility of BSI.

2223.   Statistical Phase Noise Elimination for Amyloid Plaque Detection
Tetsuya Yoneda1, Koji Hashimoto1, Akihiko Kuniyasu2, Toshinori Hirai1, Mika Kitajima1, Mamoru Hashimoto1, Nan Kurehana1, Michiya Iwata1, Motohira Mio3, Sosuke Yoshinaga1, Hiroaki Terasawa1, Manabu Ikeda1, and Yasuyuki Yamashita1
1Kumamoto University, Kumamoto, Kumamoto, Japan, 2Sojo University, Kumamoto, Japan, 3Fukuoka University Chikushi Hospital, Fukuoka, Japan

In this study, we suggested statistical method to effectively distinguish the signal of AP from phase noise on MR-phase image resulting in reducing scan duration for clinical application of diagnosis of AD. Phase Difference Enhanced Imaging-image of human brain showed dark rim sign expected as AP deposition but did not show background phase noise containing iron deposition due to aging by statistical noise elimination. Our method may be applicable for clinical image diagnosis for AD with reasonable scan duration less than 4 min.

2224.   Ex-vivo brain MR morphometric-pathologic investigation in a community cohort of older adults.
Junxiao Yu1, Aikaterini Kotrotsou1, Arnold M. Evia1, Julie A. Schneider2, Sue E. Leurgans2, David A. Bennett2, and Konstantinos Arfanakis1
1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, 2Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States

Alzheimer's disease (AD) pathology commonly coexists with other age-related neuropathologies in the brain of older persons. Although brain atrophy is considered a biomarker of AD pathology, other neuropathologies may also lead to brain atrophy, and only a handful of studies with a number of limitations have combined brain MR volumetry/morphometry with measures of neuropathology obtained after death. Thus, the relation between brain atrophy and age-related neuropathology is not well-established. The purpose of this investigation was to assess the neuropathologic correlates of brain macrostructure by combining ex-vivo MRI RAVENS maps and pathology information on a large community cohort of older persons.

2225.   Is the Superficial White Matter Important in Alzheimer’s Disease?
Owen R. Phillips1,2, Shantanu H. Joshi3, Fabrizio Piras4, Maria D. Orfei4, Mariangela Iorio4, Katherine L. Narr3, David W. Shattuck3, Carlo Caltagirone1,2, Gianfranco Spalletta4, and Margherita Di Paola1,5
1Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, roma, Lazio, Italy, 2Neuroscience, University of Rome “Tor Vergata”, Rome, Roma, Italy, 3Neurology, Ahmanson Lovelace Brain Mapping Center, Los Angeles, CA, United States, 4Neuropsychiatry Laboratory, Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, Rome, Roma, Italy, 5Human Studies, LUMSA University, Rome, Italy

The late myelinating superficial white matter (SWM) comprised of intracortical myelin and short-range association fibers has not received much attention in Alzheimer’s disease (AD) research. As the SWM is vulnerable to the normal effects of age, we hypothesized that it would be impaired in AD. We used a combined cortical pattern matching and DTI approach to measure mean diffusivity. We found significant increases in mean diffusivity across most of the brain in AD patients, which suggest the tissue is impaired. Given the unique cellular makeup and its importance in neuronal synchrony, the SWM may play an important role in AD.

2226.   Nano-antioxidants improve axonal transport deficits in a mouse model of Alzheimer’s disease
Kelly Ann Moore1, Errol Loïc Samuel2, James Tour2, and Robia G Pautler1
1Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States, 2Department of Chemistry, Rice University, Houston, Texas, United States

Studies have shown in multiple models of Alzheimer’s disease that deficits in fast axonal transport develop before amyloid-beta plaque and tau deposition, with oxidative stress being implicated in the process. Using an APP/PSEN1 model of Alzheimer’s disease we demonstrate via manganese enhanced MRI a deficit in the axonal transport of this model. Additionally we show that these deficits can be reversed with the administration of nano-antioxidant PEG-ylated-hydrophilic carbon clusters.

2227.   Comparison of Relaxation, Magnetization Transfer, and Diffusion Tensor Measurements in the Hippocampal Formation between APP, PS1, and Control Mice
Sheryl L Herrera1, Heather Whittaker2, Shenghua Zhu3, Vanessa L Palmer4, Richard Buist5, Xin-Min Li6, Jonathan D Thiessen7,8, and Melanie Martin9,10
1Physics & Astronomy, University of Mantioba, Winnipeg, Manitoba, Canada, 2Biopsychology program, University of Winnipeg, Winnipeg, Manitoba, Canada, 3Pharmacology & Therapeutics, University of Mantioba, Winnipeg, Manitoba, Canada, 4Biomedical Engineering, University of Mantioba, Winnipeg, Manitoba, Canada, 5Radiology, University of Mantioba, Winnipeg, Manitoba, Canada, 6Psychiatry, University of Alberta, Edmonton, Alberta, Canada, 7Imaging Program, Lawson Health Research Institute, London, Ontario, Canada, 8Medical Biophysics, Western University, London, Ontario, Canada, 9Physics, University of Winnipeg, Winnipeg, Manitoba, Canada, 10Biomedical Engineering, Physics &Astronomy, Pharmacology &Therapeutics, Radiology, University of Mantioba, Winnipeg, Manitoba, Canada

Quantifying structural changes in the hippocampal formation (HF) and surrounding white matter with MRI can improve both the diagnosis and understanding of AD. In this study, anatomical details visible only in DEC maps allowed ROIs to be defined and applied to all quantitative MRI maps. Many significant differences were found in MRI metrics between the transgenic mice when compared with controls and in some cases between transgenic strains themselves. Quantitative MRI methods are useful for determining changes in tissue structure and content within the HF and surrounding WM tracts mouse models of AD. This is the first step toward longitudinal in vivo studies correlated with histopathology.

2228.   Improved Correlation of Iron to R2 and R2* in Alzheimer’s Disease-Affected White Matter
Christos Michaelides1, David J Lythgoe1, Harold G Parkes2, Claire Troakes3, Istvan Bodi4, Tina Geraki5, Amy H Herlihy6, and Po-Wah So1
1IOPPN, King's College London, London, United Kingdom, 2CR-UK Clinical MR Research Group, Institute of Cancer Research, Sutton, London, United Kingdom, 3MRC London Neurodegenerative Diseases Brain Bank, Department of Clinical Neuroscience, IOPPN, King's College London, London, United Kingdom, 4Clinical Neuropathology & London Neurodegenerative Diseases Brain Bank, King's College London, London, United Kingdom, 5Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom, 6Agilent Technologies, Yarnton, Oxfordshire, United Kingdom

Iron dysregulation may be a contributing factor to neuronal cell death in Alzheimer’s disease. MR relaxometry and MT measurements, in fixed post-mortem human AD and control samples, were correlated with direct iron assessment, using synchrotron radiation X-ray fluorescence mapping. The correlation of iron against MT or luxol fast blue staining were significantly different between control and AD samples, indicating a change in the relationship of iron and myelin in AD. R2 and R2* values demonstrated greater correlation to iron in AD-affected white matter than control, potentially impacting the clinical relevance for R2 and R2* relaxometry to assess iron in vivo.

2229.   Inter and intra network connectivity predicts the evolution of MCI over time and the conversion from MCI to AD
Elena Makovac1, Laura Serra1, Chiara Mastropasqua1, Mario Torso1, Barbara Spano'1, Giovanni Giulietti1, Carlo Caltagirone2,3, Mara Cercignani1,4, and Marco Bozzali1
1Neuroimaging laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, Italy, 2Department of Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, Roma, Italy, Italy, 3Department of Neuroscience, University of Rome ‘Tor Vergata’, Rome, Italy, Italy, 4Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, Sussex, United Kingdom

Altered functional characteristics have been reported in amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD). Patients with amnestic mild cognitive impairment (aMCI) have higher probability to convert to AD than elderly controls. Different RS-fMRI networks (i.e., the inter-network connectivity) interact with each other in determining higher level functions and dysfunctions. Here, we report that both intra- and inter-network connectivity can predict in MCI patients the conversion to AD at follow-up. Our results demonstrate that AD is associated with widespread loss of both intranetwork and internetwork correlations and this alteration can be observed already in preclinical stage of the disease.

2230.   The Background Brain Network Plays a Compensatory Role in Patients with Amnestic Mild Cognitive Impairment
Wutao Lou1, Lin Shi2, Defeng Wang1, Winnie CW Chu1, Vincent CT Mok2, Sheung-Tak Cheng3,4, and Linda CW Lam5
1Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 2Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 3Department of Psychological Studies, Hong Kong Institute of Education, Shatin, Hong Kong, 4Center for Psychosocial Health and Aging, Hong Kong Institute of Education, Shatin, Hong Kong, 5Department of Psychiatry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong

The background brain activity was considered to reflect the cognitive state of participants maintained the task. In this study, the background network efficiency of the working memory network of 17 aMCI patients and 19 controls were analyzed by using fMRI during a visuospatial working memory task. The aMCI patients showed increased local efficiency compared to normal controls and suggested aMCI patients have to pay more effort to complete the task due to memory impairment and suggest the compensatory property of the background network.

2231.   Simultaneous ASL/FDG-PET Imaging of Frontotemporal Dementia
Jing Zhang1,2, Elizabeth Finger1,2, Udunna Anazodo2,3, Julia MacKinley2, John Butler2, Frank Prato2,3, and Keith St Lawrence2,3
1Department of Clinical Neurological Sciences, University of Western Ontario, London, Ontario, Canada, 2Lawson Health Research Institute, London, Ontario, Canada,3Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada

This study compared the ability of ASL and FDG-PET to distinguish FTD patients from controls. ASL and FDG-PET images of 11 FTD patients and 10 age- and gender-matched controls were acquired simultaneously. Cerebral blood flow (CBF) and FDG-PET were positively correlated on the normalized mean values across the gray matter (GM), white matter, frontal and temporal lobes. Significant group differences in both CBF and FDG uptake were found in the GM and the frontal lobe. The results suggest that ASL may be a promising alternative to FDG-PET for detecting regional functional dysfunction associated with FTD.

2232.   Whole-Brain Correlation between Microstructural Alterations and Cognitive Performance of Alzheimer Disease Studied by Diffusion Kurtosis Imaging
Hongyan Ni1, Lixiang Yuan2, Yuanyuan Chen3, Man Sun2, Jianzhong Yin1, and Xu Yan4
1Tianjin First Central Hospital, Tianjin, China, 2First Central Clinical College, Tianjin Medical University, Tianjin, China, 3Tianjin University, Tianjin, China, 4MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China

To evaluate the correlation between the whole brain non-Gaussian diffusion changes and cognitive performance in Alzheimer¡¯s disease (AD) patients, voxel-wise multiple regression analyses were performed between the diffusion kurtosis imaging (DKI) indices (MK, FA and MD) and the Mini-Mental Status Examination (MMSE) scores respectively. Results shown that indices of DKI, especially MK detected more regions correlated between the indices and the MMSE scores. Thus DKI may be a more powerful compensatory technique in diagnosing and monitoring the AD progression than conventional diffusion tensor imaging (DTI).

2233.   Effect of Antiepileptic Treatment on Hippocampal Activity in Alzheimer’s Disease measured by ASL
Weiying Dai1, David C. Alsop1, and Daniel Z. Press2
1Radiology, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, United States, 2Neurology, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, United States

Increased hippocampal perfusion in early AD has been reported, but the underlying mechanism is still not clear. We hypothesized that epileptiform activity occurs in the hippocampus with AD and causes increased perfusion. Here, we designed a placebo-controlled study using an antiepileptic drug, Levetiracetam to modulate epileptic activity of the hippocampus. Nine subjects with AD were scanned following drug or placebo. We observed increased rather than decreased hippocampal perfusion with Levetiracetam. These findings suggest a more complex behavior of drug and epileptic activity effects in AD.

2234.   Tensor-Based Morphometry reveals structural differences between Down syndrome and Alzheimer’s disease mouse model brains
Nick M Powell1,2, Holly E Holmes2, Da Ma1,2, Marc Modat1, Jorge Cardoso1, Frances K Wiseman3, Victor LJ Tybulewicz4, Elizabeth MC Fisher3, Mark F Lythgoe2, and Sebastien Ourselin1
1Centre for Medical Image Computing, University College London, London, England, United Kingdom, 2Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 3Department of Neurodegenerative Disease, Institute of Neurology, University College London, London, United Kingdom, 4MRC National Institute for Medical Research, London, United Kingdom

We applied optimised protocols for high-resolution ex vivo MRI phenotyping of mouse brains, together with a fully automated image processing software pipeline, to perform tensor-based morphometry (TBM) on individual mouse models of Down syndrome and Alzheimer’s disease (the Tc1 and J20 models, respectively), as well as Tc1/J20 double mutants. In a comparison between Tc1/J20 and J20 brains, our analysis revealed significant differences in local morphology (volume) throughout the brain, including within the thalamus, olfactory bulbs and cerebellum. Our analysis highlights potential regions for later histology, and may inform behavioural investigations.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2235.   Intracellular pH measured by 31P MR-Spectroscopy predicts site of progression in recurrent glioblastoma under antiangiogenic therapy with bevacizumab.
Katharina Johanna Wenger1, Oliver Bähr1, Elke Hattingen2, and Ulrich Pilatus2
1Neurooncology, Goethe-University Frankfurt, Frankfurt, Hessen, Germany, 2Neuroradiology, Goethe-University Frankfurt, Frankfurt, Hessen, Germany

In solid tumors, major changes in the expression and/or activity of plasma membrane ion pumps and transporters facilitate proton efflux and enable tumor cells to maintain a higher intracellular pH (pHi), while the microenvironment (pHe) is commonly more acidic compared to normal differentiated adult cells. An alkaline pHi supports various mechanisms involved in cellular proliferation and limits apoptosis, therefore promoting cell survival. We proposed that these early changes in pH take place before an MR-detectable recurrence occurs. To prove our hypothesis, we employed in-vivo 31P MR spectroscopic imaging (MRSI) in patients with recurrent glioblastoma (rGBM) before and under antiangiogenetic therapy (bevacizumab, BEV) until tumor progression. According to the predefined criteria by Pope et al. for distant or diffuse tumor progression, 14 patients of our institution were selected based on their tumor progression patterns at time of on-study progression (subsequent tumor). An area of interest for voxel selection on baseline MRSI data was defined retrospectively at the site of the subsequent tumor. The area of interest showed no detectable lesions before BEV on standard MRI sequences. The pHi in the area of interest (subsequent tumor) was significantly higher than the pHi of the contralateral normal appearing tissue (control) (p < 0.001) and similar to the pHi of the existing tumor. Elevated pHi in radiographically normal appearing tissue at baseline can predict the site of subsequent progression in patients with recurrent glioblastoma treated with BEV.

2236.   The Improved Detection of 2-Hydroxyglutarate In Gliomas at 7 T Using High-Bandwidth Adiabatic Refocusing Pulses
Uzay E Emir1, Sarah Larkin2, Nick de Pennington2, Natalie Voets1, Puneet Plaha3, Richard Stacey3, James Mccullagh4, Stuart Clare1, Peter Jezzard1, Christopher Schofield4, Olaf Ansorge2, and Tom Cadoux-Hudson3
1FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom, 2Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, United Kingdom, 3Department of Neurosurgery, John Radcliffe Hospital, Oxford University Hospitals NHS Trust, Oxford, Oxfordshire, United Kingdom, 4Department of Chemistry, University of Oxford, Oxford, Oxfordshire, United Kingdom

Mutations in IDH1 and IDH2 occur in up to 80% of a variety of glioma sub-types and lead to the production of MR detectable metabolite, 2-hydroxyglutarate (2-HG). In this abstract, we report results from a new acquisition protocol at 7T to detect 2-HG and the rest of the brain chemical profile in mutant IDH1/2 glioma patient with a higher sensitivity than has previously been achieved at clinical field. The new method at 7T is not only expected to increase diagnostic accuracy but also shorten the duration of the scan.

2237.   Characterizing regional heterogeneity of glioblastoma: regions representing metabolic aggression in enhancing and non-enhancing components
Natalie Rosella Boonzaier1,2, Timothy J Larkin2,3, Sarah Leir3, Laila A Mohsen4, Adam Young3, Victoria C Lupson2, and Stephen J Price2,3
1Department of Clinical Neurosciences, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom, 2Wolfson Brain Imaging Centre, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 3Division of Neurosurgery, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom, 4Department of Radiology, University of Cambridge, Cambridge, United Kingdom

Glioblastomas are the most aggressive of the primary brain tumours in adults. The intratumoral heterogeneity that these lesions demonstrate is most likely the reason behind treatment failure. Characterizing regional heterogeneity, focusing on regions of combined diffusion and perfusion properties with associated metabolically aggressive profiles that go beyond the contrast-enhancing lesion, and into the less-understood non-enhancing component, may aid in understanding treatment failure and inevitable recurrence, a phenomenon that locally begins within the non-enhancing component of the tumor.

2238.   Longitudinal MRS imaging of 2-hydroxyglutarate in brain tumors in vivo
Sandeep Ganji1, Zhongxu An1, Dianne Mendelsohn1, Marco Pinho1, Edward Pan1, Kevin Choe1, Elizabeth Maher1, and Changho Choi1
1University of Texas Southwestern Medical Center, Dallas, TX, United States

The present work reports first longitudinal MRS imaging of 2-hydroxyglutarate (2HG) measures in brain tumors using optimized PRESS TE = 97 ms at 3T. Metabolites measures were measured in six clinically stable brain tumors, over a period of 8 – 18 months. The coefficient of variance (CoV) of 2HG was 1.1% over six subjects and 22 scans. The CoV of tCho, Glu and Gln were 3.5%, 11.1% and 10.3%, respectively. The mean 2HG levels over the tumor region remained within 0.2 to 0.8 mM across the time points.

2239.   Volumetric MRSI as a tool to guide and monitor radiotherapy treatment in patients with glioma
Anouk Marsman1, Sulaiman Sheriff2, Doris D. Lin1, Andrew A. Maudsley2, Lawrence Kleinberg3, and Peter B. Barker1
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States, 2Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida, United States, 3Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States

Volumetric echo-planar spectroscopic imaging (EPSI) is a promising technique for mapping human brain tumors, based on elevated lesion choline (Cho) signals. This abstract reports the results of an interim analysis of an on-going project to determine if post-surgical EPSI has a role in radiotherapy planning in subjects with high-grade glioma, as well as to investigate the effects of treatment on tumor metabolism.

2240.   Pilocytic astrocytoma: NAA is not NAA
Benita Tamrazi1, Ashok Panigrahy2, and Stefan Bluml1,3
1Children's Hospital Los Angeles/USC, Los Angeles, CA, United States, 2Children's Hospital of Pittsburgh, Pittsburgh, PA, United States, 3Rudi Schulte Research Institute, Santa Barbara, CA, United States

MRS spectra of pediatric pilocytic astrocytoma generally show low creatine and prominent choline. Perplexingly, most spectra, including those acquired from large lesions with no partial volume of surrounding tissue, also show residual signal that appears to be consistent with N-acetyl-aspartate. In this study we analyze the precise chemical shift of the peak and demonstrate that the signal is indeed not consistent with NAA. We also show that the precise position of this peak improves the separation of regular grade II and grade III astrocytomas from pilocytic astrocytomas.

2241.   Molecular subgroups of medulloblastoma identification by MR Spectroscopy
Stefan Bluml1,2, Ashley Margol3,4, Ashok Panigrahy5, Richard Sposto3,6, Rebekah Kennedy3, Marvin D Nelson1, and Shahab Asgharzadeh3,4
1Children's Hospital Los Angeles/USC, Los Angeles, CA, United States, 2Rudi Schulte Research Institute, Santa Barbara, CA, United States, 3Children's Hospital Los Angeles and Saban Research Institute, Los Angeles, CA, United States, 4Department of Pediatrics, Keck School of Medicine, University of Southern California, CA, United States, 5Children's Hospital of Pittsburgh, Pittsburgh, PA, United States, 6Department of Preventive Medicine, Keck School of Medicine, University of Southern California, CA, United States

Medulloblastomas are the single most prevalent pediatric brain tumor. Recently, analysis of tumor specimen identified four molecular subtypes, with “sonic hedgehog (SHH)” and “WNT” subtypes carrying significantly lower risk for disease dissemination and poor outcome than “Group 3” or “Group 4”. In this retrospective study we show that in vivo MR spectroscopy (MRS) can be used to predict the molecular subtypes.

2242.   Early Tumor Response to Radiochemotherapy using 1D PRESS and 2D Correlated Spectroscopy
Xi Long1,2, Daniel Ramirez-Gordillo1, Huijun Liao1, Ben Rowland1, Jong-Woo Lee3, Nils Arvold4, Patrick Wen4, Srinivasan Mukundan1, Raymond Huang1, and Alexander P Lin1
1Center for Clinical Spectroscopy, Brigham and Women’s Hospital, Boston, MA, United States, 2Radiology Department, Union Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, Hubei, China, 3Department of Neurology, Brigham and Women’s Hospital, Boston, MA, United States, 4Division of Neuro-Oncology, Brigham and Women’s Hospital, Boston, MA, United States

Non-invasive and quantitative, magnetic resonance spectroscopy is ideally suited for treatment monitoring in brain gliomas. Recent studies have demonstrated the use of two-dimensional correlated spectroscopy (2D-COSY) for the evaluation of multiple metabolites. The goal of this study was to examine the efficacy of 2D-COSY compared to conventional MRS for the evaluation of brain tumors before and after radiochemotherapy. Our results demonstrate that 2D-COSY method provides similar results as 1D-MRS and can potentially provide additional metabolic information that may impact therapy.

2243.   MRS changes in diffuse intrinsic pontine gliomas correlate with survival
Stefan Bluml1,2 and Ashok Panigrahy3
1Children's Hospital Los Angeles/USC, Los Angeles, CA, United States, 2Rudi Schulte Research Institute, Santa Barbara, CA, United States, 3Children's Hospital of Pittsburgh/UPMC, Pittsburgh, PA, United States

Diffuse intrinsic pontine glioma (DIPG) carry the worst prognosis in pediatric neurooncology, with the majority of patients dying within six to 18 months after diagnosis. Due to the lack of tissue samples, small patient numbers, and the challenges of clinical research in the pediatric population, there has been no improvement in outcomes for decades. This study demonstrates that serial MRS identifies subgroups of “longer survival” vs. “shorter survival” survival at an early stage of the disease. This finding demonstrates that MRS could be used to adjust therapies in individual patients but also to evaluate the effectiveness of new treatment strategies in a timely fashion.

2244.   Glycine is a potential biomarker for malignant transformation in brain tumors
Changho Choi1, Sandeep Ganji1, Zhongxu An1, Dianne Mendelsohn1, Marco Pinho1, Edward Pan1, Kevin Choe1, and Elizabeth Maher1
1University of Texas Southwestern Medical Center, Dallas, Texas, United States

We report Gly elevation in brain tumors. Gly was measured, with PRESS TE=97ms at 3T, in five subjects with gliomas in vivo. In a WHO grade 3 oligodendroglioma patient, the Gly level was substantially higher in the tumor than in the contralateral. In three patients with glioblastomas, Gly was elevated by 10 fold or more. A longitudinal study in an oligoastrocytoma patient indicated that Gly increases with tumor progression. Our data suggest that Gly may be not only a useful biomarker for evaluating the tumor malignancy but also a noninvasive tool for monitoring the malignant transformation.

2245.   Evaluating brain metabolites in patients with glioma using short and long TE MRSI at 3T and 7T
Yan Li1, Marisa Lafontaine1, Susan Chang2, and Sarah J Nelson1,3
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, United States, 2Deparmenf of Neurological Surgery, University of California, San Francisco, California, United States, 3Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California, United States

The purpose of this study was to compare the metabolite profiles that were acquired using conventional long echo time MRSI at 3T with short echo time MRSI at 3T and 7T in patients with glioma. The differences in Cho, Cr and NAA between acquisitions define the critical role of relaxation times in defining the observed signals. With improved quantification and metabolite detection using short echo time MRSI sequence at 7T, it would be possible to examine heterogeneity in T2 but the acquisition is limited in terms of tumor coverage compared to MRSI at 3T.

2246.   Molecular MRI Differentiation between Primary Central Nervous System Lymphoma (PCNSL) and High-grade Glioma (HGG) Using Endogenous Protein-based Amide Proton Transfer (APT) Signals
Shanshan Jiang1,2, Hao Yu1, Xianlong Wang1, Shilong Lu1, Yi Zhang2, Doon-Hoon Lee2, Hye-Young Heo2, Jinyuan Zhou2, and Zhibo Wen1
1Department of Radiology, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, China, 2Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States

We explored the imaging features of PCNSL using APT imaging of endogenous mobile proteins and peptides at 3 Tesla. Results showed that the PCNSL tumor core had significantly higher APTW signal intensities, compared to adjacent peritumoral edema and normal-appearing white matter. The PCNSL tumor core had significantly lower APTW signal intensities, intensity distribution, and total CEST signal intensities, as well as significantly higher MTR than the HGG core. APT imaging could provide additional diagnostic information to differentiate PCNSL from HGG non-invasively.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2247.   Dual-modality evaluation of tumour vasculature, morphology and metabolism via Dynamic Susceptibility Contrast MRI and FluoroEthyl Choline-PET using simultaneous PET/MR
Maria Liljeroth1, Kjell Erlandsson2, Francesco Fraioli2, David Thomas3, Enrico De Vita4, Brian Hutton2, Anna Barnes5, Simon Arridge6, Sebastien Ourselin7, and David Atkinson8
1Institute of Nuclear Medicine, Metabolism & Experimental Therapeutics, London, London, United Kingdom, 2Institute of Nuclear Medicine, Metabolism & Experimental Therapeutics, London, United Kingdom, 3Institute of Neurology, Faculty of Brain Sciences, Brain Repair & Rehabilitation, London, United Kingdom, 4National Hospital for Neurology and Neurosurgery, Lysholm Department of Neuroradiology, London, United Kingdom, 5Institute of Nuclear Medicine, Clinical Physics, London, United Kingdom,6Faculty of Engineering Science, Dept of Computer Science, London, United Kingdom, 7Dept of Med Phys & Biomedical Eng, London, United Kingdom, 8Faculty of Medical Sciences, Div of Medicine, London, United Kingdom

Simultaneous 18FFECho PET and Dynamic Susceptibility Contrast (DSC)/ Dynamic Contrast Enhanced (DCE) MRI has the potential for providing valuable information regarding tumour morphology and aggressiveness, essential for tumour staging. We present data from a conventional EPI perfusion acquisition strategy as well as a dual-echo GRE approach which allows separation of T1 and T2* effects of Gadolinium thus providing inherent rCBV correction and tracer kinetics. Results show elevated rCBV in astrocytoma relative to pineal germinoma. The specificity of 18FFE Cho provides clear outlining of tumourous regions for kinetic evaluation. PET and MRI images are also inherently coregistered using this technique.

2248.   
Prediction of progression free survival at 6 months in high grade gliomas using pre-chemoradiotherapy MRI
Lawrence Kenning1, Martin Lowry1, Martin Pickles1, Chris Rowland-Hill2, Shailendra Achawal2, Chittoor Rajaraman2, and Lindsay Turnbull1
1Centre for MR Investigations, Hull York Medical School at University of Hull, Hull, United Kingdom, 2Hull and East Yorkshire Hospitals NHS Trust, United Kingdom

We investigated whether MR parameters measured post-surgery prior to chemoradiotherapy could predict progression free survival in high grade gliomas. DTI, DSC and DCE data was acquired from 33 glioma patients prior to chemoradiotherapy. Mean and standard deviations were calculated for each parameter. Kaplan-Meier survival analysis was calculated using dichotomised parameter values. Results suggest that PK parameters derived from DCE-MRI and diffusion tensor metrics prior to adjuvant therapy predict progression-free survival. Elevated values of Ktrans, ve and vb were all significantly associated with a shorter progression-free survival interval. Blood products may prevent DSC from being clinically significant at this scan interval.

2249.   Validation of the RANO criteria for quantifying therapeutic response of human brain tumors using computer assisted medical diagnosis (CAMD) technology
Simon Salinas1, Steve Lau2, Kate Drummond3, Christen Barras2, Pramit Phal1,2, Patricia Desmond1,2, and Bradford Moffat1
1The University of Melbourne, Melbourne, Victoria, Australia, 2Radiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia, 3Neurosurgery, The University of Melbourne, Melbourne, Victoria, Australia

We evaluated the feasibility of automatic computer assisted RANO classification of glioblastoma response to therapy. We investigated the validity of the RANO criteria in 31 patients undergoing chemo and radiation therapy. It was found that the RANO assessment could be reliably performed in less than 10 minutes per patient, using a dedicated graphical user interface. RANO classification was found to significantly correlate with patient survival with stable disease patients having a significant survival advantage (41 weeks p=0.04) compared to progressive disease patients. This graphical user interface and the validation of the criteria could pave the way for clinical translation.

2250.   Novel Method for Automatic Segmentation of Infiltrative Glioblastoma
Kelvin Wong1,2 and Stephen Wong1,2
1Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Houston, TX, United States, 2Department of Radiology, Weill Cornell Medical College, New York, NY, United States

Glioblastoma Multiforme (GBM) is the most lethal and common brain cancer in adult. Our goal is to quantitatively extract the infiltrating tumor information from imaging. Infiltrative tumor is with low Gd-enhancement and is difficult to identify. To investigate the prevalence and extent of low Gd-enhancement tumor in GBM, we developed an algorithm to automatically segment the low Gd-enhancement region. The method is applied to the GBM collection in The Cancer Imaging Archive (TCIA). The proposed algorithm can robustly segment different components of the tumor including low Gd-enhancement region.

2251.   Characterising the Transition Zone from Tumor to Normal Brain in Glioblastomas using Multimodal MRI
Sarah A Leir1, Timothy J Larkin1,2, Natalie R Boonzaier2,3, Victoria Lupson2, Laila A Mohsen4, Adam Young1, and Stephen J Price1,3
1Division of Neurosurgery, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 2Wolfson Brain Imaging Centre, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 3Department of Clinical Neurosciences, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom, 4University Department of Radiology, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom

Glioblastomas are one of the most lethal cancers to affect humans. The efficacy of surgical resection and radiotherapy, the mainstays of treatment, is limited by our ability to accurately determine tumor margins. Histological evidence suggests that there is a transition zone from tumor to normal brain extending for several centimeters beyond the T1 enhancing lesion. Diffusion-based MR is a promising new imaging technique to study tumor invasion. Using multimodal MR (DTI, perfusion and spectroscopy), we identify, for the first time, that biomarkers of tumor cell presence extend up to 3 centimeters beyond the conventionally determined and subsequently treated tumor margins.

2252.   Metabolic activity of the invasive microenvironment of glioblastomas determines time to progression: a multimodal MR study
Stephen J. Price1,2, Adam MH Young1, William J Scotton1, Natalie R Boonzaier1, Victoria C Lupson2, Mary A McLean3, and Timothy J Larkin1,2
1Academic Neurosurgery Division, Dept. Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, 2Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 3Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom

Most patients with glioblastomas will die from disease progressing adjacent to the resected tumor. This invasive margin is a cardinal feature of glioblastomas and cannot be seen on conventional imaging but can be identified with diffusion tensor imaging. By outlining the DTI-defined region of tumour invasion we can use perfusion and MR spectroscopy to explore the microenvironment. This study shows that patients with more metabolically active invasive margins (defined as Cho/NAA > 0.6) have a significantly longer progression free survival. This suggests that cytotoxic therapies have increased efficacy with more proliferative and metabolically active invasive margins.

2253.   Tumour relapse prediction using multi-parametric MR data recorded during follow-up of GBM patients
Adrian Ion-Margineanu1,2, Sofie Van Cauter3, Diana M Sima1,2, Frederik Maes2,4, Stefaan W Van Gool5, Stefaan Sunaert3, Uwe Himmelreich6, and Sabine Van Huffel1,2
1STADIUS, KU Leuven - ESAT, Leuven, Belgium, Belgium, 2iMinds Medical IT, Leuven, Belgium, 3Department of Radiology, University Hospitals of Leuven, Leuven, Belgium,4PSI, KU Leuven - ESAT, Belgium, 5Department of Pedriatic Neuro-oncology, University Hospitals of Leuven, Belgium, 6Department of Imaging and Pathology - Biomedical MRI/ MoSAIC, KU Leuven, Belgium

Our study is trying to find a relation between multi-parametric MR data (T1 post contrast - MRI, T2* - MRI, FLAIR, Perfusion MRI, Diffusion MRI, MR Spectroscopy) acquired during the follow-up of 29 glioblastoma multiforme (GBM) patients and the relapse of the brain tumour after surgery, as described by the clinically accepted RANO criteria. We find that ensemble classifiers can accurately predict the outcome of the therapy with approximately one month in advance before doctors. The same results were found also when using just perfusion features.

2254.   Quantitative Brain Tumor Mapping Using Magnetic Resonance Fingerprinting
Chaitra Badve1, Matthew Rogers2, Alice Yu2, Dan Ma3, Shivani Pahwa4, Andrew Sloan5, Jeffrey Sunshine1,4, Vikas Gulani1,4, and Mark Griswold3,4
1Radiology, University Hospitals, Cleveland, Ohio, United States, 2School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States, 3Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, 4Radiology, Case Western Reserve University, Cleveland, Ohio, United States, 5Neurosurgery, University Hospitals, Cleveland, Ohio, United States

Magnetic resonance fingerprinting was used to develop quantitative relaxometry maps of brain tumors (glioblastoma, metastases, and oligodendrogliomas). The relaxometry values were compared among the different tumors within the solid tumor and peritumoral regions. This study found significant differences in the relaxometry values between each tumor in both regions studied. These findings may aid in future diagnosis and grading of brain tumors, and may serve as quantitative imaging biomarkers by which early treatment can be optimized.

2255.   MR-PET based Diagnosis of Gliomas – A Prospective Comparison of 3D MRSI and 18FET PET
Jörg Mauler1, Karl-Josef Langen1, Andrew A. Maudsley2, Omid Nikoubashman3, Christian Filss1, Gabriele Stoffels1, and N. Jon Shah1
1Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Jülich, Germany, 2Miller School of Medicine, University of Miami, FL, United States, 3Department of Neuroradiology, RWTH Aachen University, Germany

The association of spatially resolved FET uptake and MRS measures was investigated in high- and low-grade gliomas using a hybrid PET-MR scanner. This is intended to increase the sensitivity of the detection of FET negative low-grade tumours in the future. The MR spectral analysis was carried through with respect to choline, N-acetyl-aspartate, myo-inositol and lactate. 9 low-grade and 9 high-grade gliomas showed no clear association between FET uptake und the pattern of altered metabolite levels. Further investigations on a larger number of subjects are required.

2256.   Tumor classification and prediction using robust multivariate clustering of multiparametric MRI
Alexis Arnaud1,2, Florence Forbes1,2, Nicolas Coquery3,4, Emmanuel L Barbier3,4, and Benjamin Lemasson3,4
1INRIA, Grenoble, -, France, 2LJK, University Grenoble Alpes, Grenoble, -, France, 3U836, INSERM, Grenoble, -, France, 4GIN, University Grenoble Alpes, Grenoble, -, France

Multiparametric MRI combined with multidimensional advanced statistical analysis methods may allow a more efficient brain tumor characterization. We used an Expectation-Maximization algorithm and Bayesian model selection on small animal data collected at 4.7T and using four glioma models (n=37). We first detected and excluded outlier animals (n=1). Then, we built a dictionary of tumor signatures. This dictionary discriminated four tumor models.

2257.   Advanced MR Image Biomarkers and Updated Genomic Biomarkers for Brain Gliomas: Technical Point and Clinical Application
Kyung Mi Lee1, Eui Jong Kim2, Ji Hye Jang2, and Woo Suk Choi2
1Kyung Hee University Hospital, Seoul, Seoul, Korea, 2Kyung Hee University Hospital, Seoul, Korea

The DWI, MR spectroscopy, DSC, DCE of brain tumors are now widely used in the diagnosis and post-treatment evaluation of brain tumors. In the clinical setting, functional, quantitative and qualitative approaches with genomic biomarkers (IDH, MGMT, EGFR, PTEN, 1p/19q) are being applied in practice, but there are several pitfalls with all of these approaches. Understanding and applying the different imaging techniques and genomic biomarkers in a multiparametric algorithmic fashion in the clinical and research settings can be shown to increase diagnostic specificity and confidence.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2258.   Characterising patterns of tumour invasion in glioblastoma
Timothy J Larkin1, Natalie R Boonzaier1, Laila A Mohsen2, and Stephen J Price1
1Division of Neurosurgery, University of Cambridge, Cambridge, United Kingdom, 2Department of Radiology, University of Cambridge, United Kingdom

Diffusion tensor imaging (DTI) can be used to identify different patterns of tumour invasion in glioblastoma. These patterns of invasion from minimally to locally to diffusely invasive have been shown to correlate with progression free survival in these tumours. We aimed to develop an automated method of classifying patterns of invasion by measuring the distance between the edges of the bulk tumour and the invasive margin defined using DTI. Using our method we are able to distinguish different patterns of invasion.

2259.   Differentiating Tumor Progression from Pseudo-progression in Patients with Glioblastomas using DTI and DSC-MRI
Sumei Wang1, Maria Martinez-Lage2, Yu Sakai1, Sanjeev Chawla3, Sungheon G Kim3, Michelle Alonso-Basanta4, Robert A Lustig4, Steven Brem5, Suyash Mohan1, Ronald L Wolf1, Arati Desai6, and Harish Poptani1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States,3Radiology, New York University School of Medicine, New York, NY, United States, 4Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States, 5Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States, 6Hematology-Oncology, University of Pennsylvania, Philadelphia, PA, United States

The purpose of this study was to determine whether DTI and DSC MRI can help in differentiating true progression (TP) from pseudo-progression (PsP) and mixed response in glioblastoma patients demonstrating enhancing lesions within six months post chemo-radiation therapy. Nine PsP, 12 mixed response and 21 TP patients underwent DTI and DSC-MRI. Significantly elevated maximum rCBV (rCBVmax), FA, CL, CP and decreased CS were observed in TP compared to PsP. The best logistic regression model to distinguish TP from non-TP (PsP+mixed) consisted of FA, CL and rCBVmax (AUC 0.905). DTI and DSC may be helpful in differentiating PsP from TP.

2260.   IVIM-MRI Reproducibility for Functional Parametric Mapping of Treatment Response in High-Grade Glioma
Jack T Skinner1,2, Paul L Moots3, Adrienne N Dula1,2, and C Chad Quarles1,2
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 3Neurology, Vanderbilt University Medical Center, Nashville, TN, United States

Intravoxel incoherent motion (IVIM)-MRI has been shown to measure brain tumor perfusion. The effect of longitudinal treatment on IVIM estimates in glioma, however, is unknown. To elucidate these effects, functional IVIM mapping was performed. To implement this technique, IVIM reproducibility was first established in healthy subjects. f and Dwere found to be reproducible (wCV < 10%) while D* was less reproducible (wCV approximately equal16%). In patients, functional maps revealed a predominate increase in f with treatment. Though a robust decrease in D was observed, ADC remained relatively unchanged. Functional IVIM mapping may, therefore, help identify local regions of tumor progression or treatment effect.

2261.   Differentiation of High-Grade Astrocytomas from Solitary Brain Metastases: Comparing Diffusion Kurtosis Imaging and Diffusion Tensor Imaging
Yan Tan1, Hui Zhang2, Xiao-chun Wang2, Jiang-bo Qin2, Xiao-feng Wu2, Lei Zhang2, and Le Wang2
1Department of Radiology, First Clinical Medical College, Shanxi Medical University, Taiyuan, Shanxi, China, 2Department of Radiology, First Clinical Medical College, Shanxi Medical University, Taiyuan 030001, Shanxi, China

 
Preoperative differentiation between high-grade astrocytomas (HGA) and solitary brain metastasis (SBM) may contribute to more appropriate treatment plans. Diffusion kurtosis imaging (DKI) is the extension of diffusion tensor imaging (DTI), which is an MRI technique depicting the non-Gaussian water molecule diffusion 1. DKI can be of particular interest for noninvasively differentiating HGA from SBM.

2262.   Computer Aided Radiological Diagnostics: Random Forest Classification of Glioma Tumor Progression using Image Texture Parameters derived from ADC-Maps.
Johannes Slotboom1, Nuno Pedrosa de Barros1, Stefan Bauer2, Urspeter Knecht1, Nicole Porz3, Philippe Schucht3, Pica Pica4, Andreas Raabe3, Roland Wiest5, and Beate Sick6
1DRNN, Institute of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Bern, Switzerland, 2Institute of Surgical Technology and Biomechanics, University Bern, Bern, Switzerland, 3DKNS-Neurosurgery, University Hospital Bern, Bern, Switzerland, 4DOLS-Radiooncology, University Hospital Bern, Bern, Switzerland, 51DRNN, Institute of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Bern, Switzerland, 6Division of Biostatistics, ISPM, University Zürich, Zürich, Switzerland

Despite the huge amount of information provided by an MR-examination, the initial diagnosis and grading of frequently extremely heterogeneous brain tumors by visual inspection remains a difficult task. A diagnostic text often lists a number of most likely diagnoses, e.g. anaplastic astrocytoma or glioblastoma multiforme. Here we discuss a method for computer aided radiologic diagnostics on how texture parameter analysis in combination with the advanced statistical classification random forest algorithm can be used to solve important differential diagnosis problem for individual diagnostics.

2263.   Comparison of Introvoxel Incoherent Motion diffusion-weighted MR imaging and Arterial Spin labeling MR imaging in gliomas
Yuankai Lin1, Jianrui yuan Li1, Zhiqiang Zhang1, Qiang Xu1, and Zongjun Zhang1
1Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China

This abstract describes the value of intravoxel incoherent motion (IVIM) diffusion-weighted imaging(DWI) in finding characteristics of glioma and comparison between IVIM and Arterial Spin labeling(ASL) was made. IVIM has capability for detecting differences of diffusion and perfusion properties between low-grade and high-grade gliomas, and has potential as a non-invasive tool for assessment of brain glioma.

2264.   Diffusion Tensor Imaging and Pathologic Correlates of Meningiomas
Sumei Wang1, Sungheon G Kim2, Maria Martinez-Lage3, Edward B Lee3, Laurie A Loevner1, Harish Poptani1, John YK Lee4, and Suyash Mohan1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Radiology, New York University School of Medicine, New York, NY, United States, 3Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States, 4Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States

The purpose of this study was to correlate DTI metrics with the histologic findings including collagen content and Ki-67 labeling index in meningiomas. Forty-five meningiomas underwent DTI studies. High collagen was observed in fibroblastic meningiomas. Atypical meningiomas showed high Ki-67. There was a significant positive correlation between FA and collagen content (r=0.43, p<0.05), and between CP and collagen content (r=0.35, p<0.05). There was a significant negative correlation between MD and Ki67 (r=0.36, p<0.05). DTI can be helpful in predicting tumor consistency and patient outcome.

2265.   Neurite Density and Diffusion Kurtosis Characterization of Brain Tumors with Accelerated DSI
Ek T Tan1, Robert J Young2, Xiaofeng Liu1, Marcel Prastawa1, Kyung K Peck2,3, Jennifer B Rubel2, Jonathan I Sperl4, and Luca Marinelli1
1GE Global Research, Niskayuna, NY, United States, 2Radiology, MSKCC, New York, NY, United States, 3Medical Physics, MSKCC, New York, NY, United States, 4GE Global Research, Garching, Munich, Germany

Recent diffusion models such as neurite orientation dispersion and density imaging (NODDI) provide new means to characterize brain tumor tissue, but may require long scan times as multiple b-values and diffusion directionalities are also required. A compressed-sensing (CS)-accelerated diffusion spectrum imaging (DSI) approach was used to provide the data for modeling with NODDI and diffusion kurtosis for whole-brain imaging within 15 minutes. Fifteen subjects with primary brain tumors were imaged with CS-DSI with a conventional 3T scanner and 8-channel brain coil. The results suggest that the NODDI and kurtosis maps may provide improved segmentation and classification of tumor types.

2266.   Cranio-spinal radiation produces long term compromise of white matter tracts in childhood brain tumour survivors.
Logan Richard1,2, Eric Bouffet1,2, Suzanne Laughlin1, Normand Laperriere3, Kamila Szulc1, Douglas Strother4, Juliette Hukin5, Christopher Fryer5, Dina McConnell5, Fang Liu1, Jovanka Skocic1, Alexandra Mogadam1, and Donald Mabbott1,2
1The Hospital for Sick Children, Toronto, Ontario, Canada, 2University of Toronto, Toronto, Ontario, Canada, 3Princess Margaret Hospital, Toronto, Ontario, Canada, 4University of Calgary, Calgary, Alberta, Canada, 5British Columbia Children's Hospital, Vancouver, British Columbia, Canada

Investigating the longitudinal effects of cancer therapy on childhood brain tumour survivors is important in understanding their quality of life post-treatment. Our study investigates the effects of brain tumour treatment on several white matter (WM) tracts within the brain of childhood cancer survivors. We used diffusion tensor imaging to delineate specific WM tracts in brain tumour patients treated with different therapies and in healthy children. Survivors treated with craniospinal radiation exhibit compromised WM within multiple tracts including the optic radiation and inferior longitudinal fasciculus. This study provides evidence for the long-term effects of craniospinal radiation on the developing brain.

2267.   An Analysis of Variability in Diffusion Tractography of Language Fascicles
Kesshi Marin Jordan1, Eduardo Caverzasi2,3, Valentina Panara1,4, Bagrat Amirbekian1, Anisha Keshavan1, Nico Papinutto2,5, Mitchel Berger6, and Roland Henry2
1Bioengineering, University of California San Francisco & Berkeley, San Francisco, CA, United States, 2Neurology, University of California San Francisco, San Francisco, CA, United States, 3University of Toronto, Toronto, Canada, 4Institute of Advanced Biomedical Technologies, University “G. D'Annunzio", Chieti, Italy, 5Bioengineering, University of California San Francisco & Berkeley, CA, United States, 6Neurosurgery, University of California San Francisco, San Francisco, United States

Diffusion tractography remains the only method of mapping white matter noninvasively. Fascicle volume definition depends heavily on tractography implementation choices. Safe clinical deployment of these technologies requires methodological variability to be characterized and minimized. This study investigates inter- and intra- operator variability of language fascicle reconstructions in both control subjects and tumor patients, and their dependence on #streamlines/voxel threshold choice. These results indicate that probabilistic tractography methods tend to have an optimal threshold for maximum percent overlap, but reliability varies by fascicle. The analysis of average diffusion metrics show striking average FA changes between commonly used thresholds.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2268.   in a Rat Model of Cerebral Tumor, Exudate Flux is Controlled by Peritumoral Compression
James R. Ewing1, Stephen L. Brown2, Madhava P. Aryal1, Kelly Ann Keenan3, Rasha M. Elmghirbi4, Swayamprav Panda1, Hassan Bagher-Ebadian1, and Tavarekere N. Nagaraja3
1Neurology, Henry Ford Health System, Detroit, MI, United States, 2Radiation Oncology, Henry Ford Health System, Detroit, MI, United States, 3Anesthesiology, Henry Ford Health System, Detroit, MI, United States, 4Physics, Oakland University, Rochester, MI, United States

In a U251 rat model of cerebral tumor, extracellular volume was measured in the tumor, and in the normal tissue surround of the tumor via an innovative application of the Logan plot. Similarly, tumor exudate flux through the boundary of the tumor was measure via an application of a Patlak plot. Extracellular volume in the normal rim of the tumor was strongly decreased, implying compression in the tumor periphery. In 18 animals, tumor exudate flux was strongly dependent (R2=0.9) on compression of peritumoral tissue.

2269.   Study of contrast-enhanced T1-w MRI markers of cerebral radiation necrosis manifested in head-and-neck cancers, primary, and metastatic brain tumors: Preliminary findings
Prateek Prasanna1, Pallavi Tiwari1, Archana Siddalingappa2, Leo Wolansky2, Lisa Rogers2, Tai-Chung Lam3, Victoria To3, and Anant Madabhushi1
1Case Western Reserve University, Cleveland, OH, United States, 2University Hospitals, Cleveland, OH, United States, 3Tuen Mun Hospital, Hong Kong, China

In this work, we present the initial results of studying imaging differences of cerebral radiation necrosis on Gadolinium contrast-enhanced (Gd-C) T1-w MRI obtained from a unique cohort of patients treated for (a) nasopharyngeal carcinoma, (b) Glioblastoma Multiforme (GBM), and (c) metastatic brain tumors. Ability to identify changes in imaging characteristics on “pure” Radiation Necrosis (RN) with no cancer presence as observed in nasopharyngeal carcinoma, may allow for improved understanding of the changes in imaging characteristics on “mixed” RN on account of cancer presence in primary and metastatic brain tumors

2270.   DCE-MRI reveals increased peritumoral fluid flow in brain metastases after SRS
Tord Hompland1, Catherine Coolens1, Brandon Driscoll1, Warren Foltz1, Cynthia Menard1, David A. Jaffray1,2, and Caroline Chung1
1Princess Margaret Cancer Centre, Toronto, Ontario, Canada, 2TECHNA Institute/University Health Network, ontario, Canada

Here we communicate a method for measuring interstitial fluid flow in brain metastases, a potential tool to noninvasively measure changes in IFP. With this method we were able to show an increased peritumoral fluid flow 2 days following stereotactic surgery, most likely caused by an increase in tumor vasculature permeability and subsequent increase in IFP. Interstitial fluid flow also correlated with peritumoral edema. Interestingly, we also show that the fluid flow induced contrast agent transport can lead to misinterpretations of tumor volume measured by DCE-MRI depending on the time interval between injection and contrast-enhanced image acquisition.

2271.   Glioma grading using standardized rCBV depends on tumor type
Mona M Al-Gizawiy1, Melissa A Prah1, Wade M Mueller2, and Kathleen M Schmainda1,3
1Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States, 2Neurosurgery, Medical College of Wisconsin, Wisconsin, United States, 3Biophysics, Medical College of Wisconsin, Wisconsin, United States

Histopathology remains the gold standard for the diagnosis of brain tumors, even though MR imaging provides invaluable additional information on tumor behavior. Histopathological findings of 157 brain tissue specimens from 34 adult patients were matched to intraoperative surgical navigation snapshots of tissue collection sites. Preoperative leakage-corrected sRCBV differentiated between astrocytoma and oligodendroglioma grades, but this ability to distinguish between the grades was lost when different glioma types were combined for analysis. We present evidence that histologically different gliomas are also biologically distinct, characterized by significant differences in perfusion and diffusion measures, reinforcing the important role of sRCBV in glioma characterization.

2272.   Design of a 3D-Phantom to evaluate optimized imaging parameters for Time-of-Flight Angiography in mouse glioblastoma models
Carly Warren1, Michael Bock1, Jochen Leupold1, and Wilfried Reichardt1,2
1Department of Radiology Medical Physics, Universitiy Medical Center Freiburg, Freiburg, Germany, 2German Cancer Consortium (DKTK), German Cancer Center (DKFZ), Heidelberg, Germany

Glioblastomas are very heterogeneous and diffusely growing brain tumors. They initiate and maintain angiogenesis during their growth. To assess whether a novel therapeutic drug changes the vascular architecture, non-invasive imaging methods to study changes of the neo-angiogenic vasculature are urgently needed. Time-of-Flight (TOF) is an imaging technique used in Magnetic Resonance Angiography (MRA) that is able to depict pathologic vasculature based on the flow of blood. In this study a 3D-phantom is constructed to simulate the vascular tree in a mouse to analyze the effects of TOF-MRA sequence parameters on the signal intensity in the vicinity of a glioblastoma.

2273.   Minimum sample size requirements for rCBV measures in patient glioblastoma trials
Melissa A Prah1, Steven M Stufflebeam2, Eric S Paulson1,3, Jayashree Kalpathy-Cramer2, Elizabeth R Gerstner4, Tracy T Batchelor4, Daniel P Barboriak5, Bruce Rosen2, and Kathleen M Schmainda1,6
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 3Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States, 4Neurology, Massachusetts General Hospital, Boston, MA, United States, 5Radiology, Duke University Medical Center, Durham, NC, United States, 6Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States

Measures of relative cerebral blood volume (rCBV) have shown to be immensely useful in assessing brain tumor vascularity. This has led to increased interest in the use of rCBV as a biomarker of clinical outcome or in research. This work provides an estimate of the minimum sample-size requirements to power a clinical imaging trial involving glioblastoma patients for six of the most commonly used rCBV estimation methods in order to detect a parameter change of 10% or 20%. Using these results, the efficiency of clinical trials may be improved with methods requiring considerably fewer participants to address a given hypothesis.

2274.   Pretreatment Dynamic Contrast-Enhanced MR Imaging in Glioblastoma : Correlation Study with Genetic Profiles
Yoon Seong Choi1, Tyler Hyungtaek Rim2, Mina Park1, Ho-Joon Lee1, Sung Soo Ahn1, Jinna Kim1, and Seung-Koo Lee1
1department of radiology, Yonsei university college of medicine, Seoul, Seoul, Korea, 2department of ophthalmology, Yonsei university college of medicine, Seoul, Seoul, Korea

We investigated the usefulness of preoperative DCE-MRI in predicting three major genetic profiles of glioblastomas including EGFR, p53 and Ki-67, using histogram analysis. We found that Ktrans values were higher in EGFR positive tumors than EGFR negative tumors, and that Ktrans values were negatively correlated with p53 expression, thus associated with genetic profiles implicating poor prognosis in glioblastomas. We suggest that DCE-MRI might be useful in predicting genetic profiles associated with prognosis, and determining appropriate treatment strategy in patients with glioblastoma.

2275.   Understanding the Mechanism of Contrast Enhancement in Brain Tumors and Infections Through Dynamic Contrast Enhanced MRI
Mudit Gupta1, Prativa Sahoo2, Ritu Tyagi1, Rana Patir3, Sandeep Vaishya4, Neeraj Prakash4, Indrajit Saha2, and Rakesh Kumar Gupta1
1Radiology, Fortis Institute, Gurgaon, Haryana, India, 2Philips Healthcare, Gurgaon, India, 3Neurosurgery, Fortis Institute, Gurgaon, India, 4Pathology, Fortis Institute, Gurgaon, India

While conventional post-contrast MRI demonstrates pathologies, perfusion MRI does it better. We evaluated the relative contributions of plasma volume (rPV) and extracellular, extravascular volume (rEV) to the contrast enhancement of intracranial lesions -- gliomas and neurocysticerosis (NCC). Intra-group comparison revealed significantly higher rEV than rPV in NCC and no significant difference in tumors. Inter-group comparison demonstrated significantly higher rPV in gliomas vis-à-vis higher rEV in NCC. We have demonstrated that breakdown of blood-brain barrier is the predominant pathology in enhancing NCC vis-à-vis neoangiogenesis in enhancing gliomas.

2276.   Discrepancy between arterial spin labeling images and contrast-enhanced images of brain tumors
Takashi Abe1, Saho Irahara2, Yoichi Otomi2, Yuuki Obama2, Moriaki Yamanaka2, Seiji Iwamoto2, Sonoka Hisaoka2, Mungunkhuyag Majigsuren2, Delgerdalai Khashbat2, Mungunbagana Ganbold2, and Masafumi Harada2
1Institute of Health Biosciences The Tokushima University Graduate School, Tokushima, Tokushima, Japan, 2Tokushima University Graduate School, Tokushima, Tokushima, Japan

In the imaging of intra-axial brain tumors, we sometimes found hyper-intensity areas on arterial spin labeling (ASL) outside of the enhanced tumor lesions. This study investigated the clinical significance of this finding in the differential diagnosis. Images from 38 consecutive patients who underwent ASL and CE-MRI with a 3T-MR scanner were examined (21; glioma, 8; metastasis, 9; lymphoma). About one third of cases showed this finding, but any cases with brain metastasis didn’t. This finding indicating the presence of glioma or lymphoma, not brain metastasis, and indicates a new utility for ASL images in the diagnosis of brain tumors.

2277.   The complementary value of arterial spin labeling next to contrast-enhanced MRI in the diagnosis of brain tumor invasion in mouse models
Houshang Amiri1,2, Anna C. Navis3, Tom Peeters1, William P. Leenders3, and Arend Heerschap1
1Department of Radiology, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands, 2Department of Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands, 3Department of Pathology, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands

Arterial spin labeling (ASL) provides valuable information on cerebral blood flow (CBF) by using blood water molecules as an endogenous tracer. We aimed to first evaluate ASL to diagnose diffuse infiltrative glioma in well characterized xenografts mouse models and then to combine it with the commonly used method, i.e. contrast-enhanced (CE) MRI. We showed that ASL has potentials to detect diffuse infiltrative parts of tumors and therefore could be considered as a complementary value to the CE MRI by which compact growing parts of tumors are diagnosed.

2278.   Diagnostic Performance of Dynamic Susceptibility Contrast Perfusion in Glioma Grading: Comparison of Cerebral Blood Volume among Different Analysis Software
Kohsuke Kudo1, Ikuko Uwano2, Toshinori Hirai3, Hideo Nakamura4, Noriyuki Fujima1, Fumio Yamashita2, Jonathan Goodwin2, Satomi Higuchi2, and Makoto Sasaki2
1Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, Japan, 2Ultra-High Field MRI, Iwate Medical University, Morioka, Japan, 3Radiology, Kumamoto University, Kumamoto, Japan, 4Neurosurgery, Kumamoto University, Kumamoto, Japan

The purpose of the present study was to compare rCBV value of DSC perfusion and diagnostic performance of rCBV for discriminating low grade and high grade tumor among different software packages in patients with cerebral glioma. CBV maps were generated by 11 different algorithms of four commercially available software and one academic program. Diagnostic performances of rCBV for glioma grading were not statistically significant among post-processing software. However, rCBV values and cut off values for discriminating low grade and high grade gliomas were different among algorithms.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2280.   Atlas based seed analysis of resting state fMRI for pre-surgical brain mapping
Madalina E Tivarus1,2, Alexander Teghipco2, Daniel Cole3, Michael Utz1, and Ali Hussain1
1Department of Imaging Sciences, University of Rochester, Rochester, NY, United States, 2Rochester Center for Brain Imaging, University of Rochester, Rochester, NY, United States, 3Department of Psychology, Emory University, GA, United States

Resting state fMRI (rs-fMRI) is emerging as an alternative brain mapping method that is independent of patient’s ability to comply with a task, but it has yet to enter the routine clinical practice due to the complexity of post-processing needed. We proposed an atlas based patient and operator independent seed analysis for processing rs-fMRI that meets the demands of clinical practice while reliably identifying functional networks.

2281.   Resting State Functional Connectivity of the Hippocampus in Patients Receiving Radiation Therapy for Extra-Axial Tumors
Marc C Mabray1, Igor J Barani2, Suresh E Joel3, Rakesh Mullick3, and Soonmee Cha1
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Radiation Oncology, University of California San Francisco, San Francisco, CA, United States, 3General Electric Global Research, Bangalore, Karnataka, India

We aim to study the effects of radiation therapy on resting state functional connectivity. In this study we evaluated hippocampal functional connectivity in patients with extra-axial tumors receiving focal radiation therapy. We found decreased functional connectivity of the right hippocampus to the right putamen post-radiation therapy as compared to pre-radiation therapy. Further investigation into the effects of radiation dose to the hippocampus on functional connectivity and correlation with neurocognitive function is warranted. This may have implications for radiation therapy planning and provide insight into radiation related neurocognitive dysfunction.

2282.   Functional Connectivity Changes in the Presence of Brain Tumors
Noora Pauliina Tuovinen1, Francesco de Pasquale1, and Umberto Sabatini1
1Radiology, Santa Lucia Foundation, Rome, Lazio, Italy

For studying the effects of brain tumors on functional connectivity, resting state scans were acquired on 10 post-surgical glioblastoma multiforme patients. We hypothesized that the presence of tumor would affect the overal connectivity in the brain compared to healthy subjects. We ran ICA to recognize resting state networks across patients and defined nodes that were used to run the connectivity analysis. The data was analyzed using tools provided by FSL and Matlab. The results revealed reduced connectivity in the patients.

2279.   Dynamic Functional Connectivity of Motor Network in Patients with Brain Tumor
Chen Niu1, Pan Lin2, Ming Zhang1, XiaoLong Peng2, MaoDe Wang1, Wei Wang1, Wenfei Li1, Xin Liu2, and Rana Netra1
1The First Affiliated Hospital of Medical College, Xi'an Jiaotong university, Xi'an, Shaanxi, China, 2Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China

In our study, we tested the hypothesis that the dynamic functional connectivity of the motor network would associate with the underlying motor function abnormality in tumor patients. Here, We used Wavelet transform coherence (WTC) analysis to explore the temporal dynamics of connectivity between key regions of motor networks in patients with different tumor types (Low-grade gliomas, and Meningioma) in order to achieve a better understanding of the relationship underlying brain plasticity mechanisms and dynamic functional connectivity. These results can enhance our understanding of motor network functional reorganization within different tumor type.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2283.   Optimization of sample preparation for MRI of formaldehyde-fixed brains
Yann Leprince1,2, Benoît Schmitt1, Élodie Chaillou3, Christophe Destrieux4, Laurent Barantin4, Alexandre Vignaud1, Denis Rivière1, and Cyril Poupon1
1NeuroSpin, CEA, Saclay, France, 2Université Paris-Sud, Orsay, France, 3INRA, Tours, France, 4Université François-Rabelais, Tours, France

MRI of post-mortem brain specimen is often used because it allows high-resolution imaging thanks to long acquisitions times and the absence of movement. It also allows correlation with histological examination of the tissue. However, fixation with formaldehyde modifies the relaxivity and diffusion properties of tissue. This study investigates the kinetics of these modifications, and their reversibility when free formaldehyde is washed out of the tissue by soaking in saline solution.

2284.   Morphological and Microstructural Changes in the Eye and the Brain in an Experimental Glaucoma Model Induced by Crosslinking Hydrogel Injection
Leon C. Ho1,2, Ian P. Conner3,4, Xiao-Ling Yang1,3, Yolandi van der Merwe1,4, Yu Yu5, Christopher K. Leung6,7, Ian A. Sigal3,4, Ed X. Wu2, Seong-Gi Kim1,8, Gadi Wollstein3, Joel S. Schuman3,4, and Kevin C. Chan1,3
1Neuroimaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China, 3Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, 4Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, 5Division of Biomedical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China, 6University Eye Center, Hong Kong Eye Hospital, Hong Kong, China, 7Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China, 8Center for Neuroscience Imaging Research, Institute for Basic Science, Sungkyunkwan University, Suwon, Korea

Glaucoma is the second leading cause of blindness in the world and is an irreversible neurodegenerative disease of the visual system. To date, limited models have been available to provide sustained intraocular pressure elevation while keeping a clear visual axis for normal visual input to the eye. In this study, we characterized a novel experimental glaucoma model in rats using a crosslinking hydrogel that gives sustained intraocular pressure elevation and a transparent medium after intracameral injection. In vivo anatomical MRI, magic angle-enhanced MRI and diffusion tensor imaging were employed to determine the morphological and microstructural changes in the whole eye and the brain in this model.

2285.   Retinal-Choroidal Blood Flow Decreases with Age: an MRI study
Oscar San Emeterio Nateras1,2, Joseph M Harrison3, Eric R. Muir2,3, Yi Zhang2, Qi Peng2,4, Steven Chalfin3, Juan E Gutierrez5, Daniel A Johnson3, Jeffrey W Kiel3, and Timothy Q Duong2,3
1Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas, United States, 2Research Imaging Institute, San Antonio, Texas, United States,3Ophthalmology, University of Health Science Center at San Antonio, Texas, United States, 4Radiology, Albert Einstein College of Medicine, and Montefiore Medical Center, Bronx, NY, United States, 5Radiology, University of Health Science Center at San Antonio, Texas, United States

The goals of the present study were to assess the visual fixation stability achievable with cued eye blinks for blood-flow MRI and to test the hypothesis that retinal-choroidal blood flow changes with age in humans. Cued visual fixation on a target achieved adequate stability for blood flow MRI measurement. Retinal-choroidal blood flow negatively correlated with age, declining 1.8ml/100ml/min per year. Such decrease in ocular blood flow could impair delivery of oxygen and nutrients, and removal of metabolic waste, making the retina more susceptible to diseases.

2286.   Sources and mitigation of physiological noise in brainstem fMRI studied at high resolution
Laetitia Maëlle Vionnet1, Lars Kasper1,2, Michael Wyss1, Mike Bruegger1,3, and Klaas Paul Pruessmann1
1Institute for Biomedical Engineering, ETH and University Zurich, Zurich, Switzerland, 2Translational Neuromodeling Unit, ETH and University Zurich, Zurich, Switzerland, 3Center of Dental Medicine, University of Zurich, Zurich, Switzerland

Physiological noise in the brainstem is investigated on high-resolution fMRI data. We verify that this source of confound is localized around the brainstem and that a masking procedure enable tSNR enhancement.

2287.   Automated vessel segmentation from quantitative susceptibility maps at 7 Tesla
Pierre-Louis Bazin1, Audrey Fan2, Gabriela Mianowska3, Agnieska Olbrich3, Andreas Schäfer1, Arno Villringer1, and Claudine Gauthier4
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Stanford University, California, United States, 3AGH University of Science and Technology, Cracow, Poland, 4Concordia University, Montréal, Québec, Canada

This work presents a new automated segmentation method to extract detailed brain vasculature from high-resolution quantitative susceptibility maps at high field. Comparison with human raters and susceptibility-weighted contrasts indicate the suitability of the method for measuring local oxygen extraction fraction in small cortical veins.

2288.   Effectively Improving Accuracy and Reliability in Intracranial Volume Change for MR Intracranial Pressure Measurement
Yi-Hsin Tsai1, Hung-Chieh Chen2, Hsin Tung3, Da-Chuan Cheng4, Clayton Chi-Chang Chen2, Jyh-Wen Chai1,2, Hsiao-Wen Chung5, and Wu-Chung Shen6
1College of Medicine, China Medical University, Taichung, Taichung, Taiwan, 2Department of Radiology, Taichung Veterans General Hospital, Taichung, Taichung, Taiwan,3Neurological Institute, Taichung Veterans General Hospital, Taiwan, Taiwan, 4Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taichung, Taiwan, 5Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 6College of Health Care, China Medical University, Taichung, Taichung, Taiwan

Non-invasive MR intracranial pressure measurement (MR-ICP) has limited clinical applicability due to measurement errors, a great portion of which likely comes from internal jugular vein (IJV) pulsations. Experiments on normal volunteers were conducted to evaluate how the IJV flow patterns on various measurement positions affect the peak-to-peak intracranical volume changes (ICVC), which then used to estimate the MR-ICP. Results showed strong correlations between ICVC and IJV pulsatility indexes, both increasing as slices caudally shifted, quite apparently caused by right atrial hemodynamics. With properly positioned IJV measurement, the accuracy and reliability of MR-ICP measurement can be effectively improved.

Wednesday 3 June 2015
Exhibition Hall 13:30 - 15:30

2289.   Slab-wise pulse design enhances the performance of dual source parallel RF transmission at 3T
Xiaoping Wu1, Dingxin Wang1,2, Jinfeng Tian1, Sebastian Schmitter1, Vibhas Deshpande3, Tommy Vaughan1, Kamil Ugurbil1, and Pierre-Francois Van de Moortele1
1CMRR, Radiology, University of Minnesota, Minneapolis, MN, United States, 2Siemens Medical Solutions USA, Inc., Minneapolis, MN, United States, 3Siemens Medical Solutions USA, Inc., Austin, TX, United States

Previous studies have demonstrated that the use of dual source parallel RF transmission (pTx) is advantageous over standard single source RF excitation in 3T body imaging. In these studies a single RF shim set was obtained for a multislice sequence to image the entire region of interest and therefore the resulting pulses are of suboptimal performance since the full degrees of freedom (DOF’s) available in the pulse design are not utilized. Recently, a slab-wise pulse design strategy was introduced to make maximum use of the DOF’s in pulse design and was demonstrated capable of providing enhanced RF performance when designing pTx multiband pulses. In this study, we utilize this slab-wise design strategy to evaluate the performance of a 3T birdcage body coil when operated in the dual transmit mode, and compare it to the conventional single transmit circularly polarized mode. RF shimming was conducted with local SAR control based on electromagnetic simulations of the birdcage coil.

2290.   Sound synchronization and motion compensated reconstruction for speech Cine MRI.
Pierre-André Vuissoz1,2, Freddy Odille1,2, Yves Laprie3,4, Emmanuel Vincent3,5, and Jacques Felblinger6,7
1Imagerie Adaptative Diagnostique et Interventionnelle, Université de Lorraine, Nancy, France, 2U947, INSERM, Nancy, France, 3LORIA, Université de Lorraine, Nancy, France,4LORIA, CNRS, Nancy, France, 5LORIA, INRIA, Nancy, France, 6University Hospital Nancy, Nancy, France, 7CIC-IT 1433, INSERM, Nancy, France

 
To construct an articulatory model of the vocal tract 10 sentences were pronounced and recorded at 3T using balanced-SSFP multiphase sequences with a resolution of 256x256. An optical microphone was used to record the speech during an 80 second scan. A noise reduction algorithm is applied before aligning each acoustic sentence onto a median template sentence. A cine loop of 128 images for each sentence is reconstructed using a motion compensated sliding window algorithm (80 ms) producing a reconstructed frame rate above 100 Hz. Each cine loop enables the delineation of the vocal tract with sufficient spatial and temporal resolution.

2291.   Diffusion tensor imaging of the auditory nerve in patients with long-term single-sided deafness
Sjoerd B Vos1,2, Wieke Haakma3,4, Huib Versnel1, Martijn Froeling3, Lucienne Speleman1, Pieter Dik5, Max A Viergever2, Alexander Leemans2, and Wilko Grolman1
1Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht, Netherlands, 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 3Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 4Department of Forensic Medicine & Comparative Medicine Lab, Aarhus University, Denmark, 5Department of Pediatric Urology, University Children's Hospital UMC Utrecht, Utrecht, Netherlands

The viability of the auditory nerve in deaf patients is critical in hearing recovery after cochlear implantation (CI). The nerve degenerates following cochlear hair cell loss and the amount of degeneration varies between ears. DTI may yield a measure of nerve degeneration by allowing noninvasive estimates of the nerve’s microstructure. We show the first use of DTI to image the auditory nerve using a specialized acquisition protocol on a clinical 3T scanner. Our results show a bilateral decrease in FA in unilaterally deaf patients compared to normal-hearing controls. No differences were observed between the deaf and healthy-sided nerves in patients.

2292.   Size of vestibular endolymph in patients with isolated lateral semicircular canal dysplasia
Shinji Naganawa1, Hisashi Kawai1, Michihiko Sone2, and Mitsuru Ikeda3
1Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan, 2Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Japan, 3Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan

Endolymph size in the vestibule of patients with Isolated vestibular-lateral semicircular canal dysplasia (LSCCD)is larger than those without LSCCD. The current MRI diagnostic cut-off value for significant vestibular endolymphatic hydrops (>50%) might not be appropriate for ears with LSCCD.

2293.   MR Elastography of Skull Base Tumors
John Huston III1, Arvin Arani1, Nikoo Fattahi1, Kevin J Glaser1, David S Lake1, Armando Manduca1, Joshua D Hughes2, Jamie J Van Gompel2, and Richard L Ehman1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States, 2Neurosurgery, Mayo Clinic, Rochester, Minnesota, United States

Tumors of the skull base vary in stiffness; however, stiffness cannot reliably be predicted with conventional MRI sequences. Stiff tumors can result in a difficult surgical resection with extended operative time and increased risk to the patient. In addition, with the increasing role of endoscopy, knowing tumor stiffness prior to surgery could be critical to decide between an open or endoscopic approach. The goal of this study was to determine the potential of MR Elastography to preoperatively assess the stiffness of skull base meningiomas, pituitary adenomas, and vestibular schwannomas.

2294.   The merged images with different central frequencies can reduce banding artifact of 3D-SSFP MR cisternography
Koji Matsumoto1,2, Hajime Yokota3,4, Hiroki Mukai4, Ken Motoori4, Toshiaki Miyachi2, Yoshitada Masuda1, and Takashi Uno4
1Department of Radiology, Chiba University Hospital, Chiba, Chiba, Japan, 2Division of Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan, 3Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan, 4Diagnostic Radiology and Radiation Oncology, Chiba University, Chiba, Japan

Magnetic resonance (MR) cisternography using three dimensions steady-state free precession (3D-SSFP) is widely used for visualizing the inner ear. However, local magnetic field of the inner ear is easy to be heterogeneous due to surrounding air cells. The heterogeneity causes phase shift in pixels and banding artifact on 3D-SSFP. Although addiction of changing phase cycling is used to reduce banding artifact, it is available only in advanced machines. Varying central frequency can cause phase shift and change locations of banding artifact. The merged images with different central frequencies can reduce banding artifact of 3D-SSFP.

2295.   T1lower case Greek rho weighted imaging in middle ear cholesteatoma
Koji Yamashita1, Akio Hiwatashi1, Osamu Togao1, Kazufumi Kikuchi1, Tomoyuki Okuaki2, Nozomu Matsumoto3, Koji Kobayashi4, and Hiroshi Honda1
1Clinical Radiology, Graduate School of Medical Science, Kyushu University, Fukuoka, Fukuoka, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3Otorhinolaryngology, Kyushu University, Fukuoka, Japan, 4Medical Technology, Kyushu University hospital, Fukuoka, Japan

T1ƒÏ weighted imaging is sensitive to slow spin motions in tissue, and may provide information about the macromolecular properties of tissues. Therefore clinical application of the technique is of increasing importance. The aim of our study was to investigate the feasibility of T1ƒÏ imaging in diagnosing cholesteatoma. In this study, we compared the differences of average T1ƒÏ values between cholesteatoma and non-cholesteatoma group. As a result, cholesteatoma can be distinguished from other middle ear diseases. Although the precise mechanism of pathogenesis is not fully elucidate, our results will help us for a better understanding of biological behavior in cholesteatoma.

2296.   Surgical validation of extracranial facial nerve magnetic resonance tractography
Arnaud ATTYE1,2, Alexandre KARKAS3, Irene TROPRES4, Laurent LAMALLE4, Felix RENARD5, Georges BETTEGA6, Christian RIGHINI3, and Alexandre KRAINIK5
1Neuroradiology, Grenoble University Hospital, Grenoble, Rhône Alpes, France, 2UMS IRMaGe, Grenoble, Rhône Alpes, France, 3Otolaryngology, Grenoble University Hospital, Rhône Alpes, France, 4UMS IRMaGe, Rhône Alpes, France, 5Neuroradiology, Grenoble University Hospital, Rhône Alpes, France, 6Maxillofacial Surgery, Grenoble University Hospital, Rhône Alpes, France

Magnetic resonance tractography of the cranial nerves is a promising tool. Yet, in order to validate the quality of quantitative data yielded from this technique, the course of nerve fibres must be confirmed surgically. This prospective study is the first work that assessed the feasibility and reliability of extracranial facial nerve magnetic resonance tractography using in vivo data, based on surgical photos and per-operative nerve stimulation. We successfully identified facial nerve, in relation to the parotid tumors, in all patients and performed quantitative microstructural analysis for 52 facial nerves. The outcome would be to aid future medical studies examining nerve dysfunction.

2297.   A Study of MS Based on a Fusion Quantitative Analysis Model of DTI
Heather Ting Ma1,2, Pengfei Yang1, Chenfei Ye1, Jun Wu3, Xuhui Chen3, and Jinbo Ma1
1Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, Guangdong, China, 2Radiology Department, Johns Hopkins University, Baltimore, MD, United States, 3Department of Neurology, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China

This study aimed at exploring lesion detection of multiple sclerosis (MS) which couldn¡¯t be seen on conventional MRI. The whole brain voxel-by-voxel DTI analysis was performed on clinical data with a fusion quantitative analysis model, which was based on TBSS and VBA method with an anisotropic filter. Quantitative comparison result for the fusion model demonstrated statistically significant reduction of FA values in all MS patients compared with controls. The lesions mainly located in corpus callosum, corticospinal tract, occipital lobe, and optic tract. The optic tract lesions may be the direct cause for the typical clinical symptoms of visual dysfunction in MS patients.

2298.   A Noise Suppression Approach in the Quantitative Analysis of DCE Images
Renjie He1, Yao Ding2, Clifton Fuller2, Qi Liu1, and Weiguo Zhang3
1United Imaging Healthcare America, Houston, Texas, United States, 2MDACC, Texas, United States, 3United Imaging Healthcare, Shanghai, China

Instead of averaging over multiple (repetitive) acquisitions to reduce the parameter map uncertainty caused by noise in the head and neck region, firstly we introduce a non-local means spatial filtering to reduce the noise from a single acquisition. The noise is further suppressed by incorporating model-based filtering originated from the sparse coding theory where a joint-dictionary is applied. The joint-dictionary also provide an approach to extrapolate the flip angles from the collected 6 flip angles data set to the regenerated 28 virtual flip angles. Finally, we construct another model-based full dictionary to retrieve the T1 from the reconstruction of 28 flip angles, and S0 is acquired by least square estimation from the T1 map.

2299.   Application of Two-compartmental Pharmacokinetic Analysis with and without Vascular Term for Differentiating Benign and Malignant Spinal Tumors Measured by DCE-MRI
Ning Lang1, Hon J Yu2, Huishu Yuan1, and Min-Ying Su2
1Department of Radiology, Peking University Third Hospital, Beijing, China, 2Tu&Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, United States

DCE-MRI was performed to differentiate 4 spinal lesions (9 myeloma, 85 metastatic cancer, 7 lymphoma, 24 benign tuberculosis). Two-compartmental pharmacokinetic model was used to obtain Ktrans and kep, by using the fast and medium blood curves, with and without considering the vascular term vp. The results showed that despite a rapid wash-in seen in some cases, the obtained vascular component was still low. The kep analyzed by using the medium blood curve was the best parameter to differentiate these 4 lesion groups. When the term vp was considered, it had a diagnostic value, but the kep might become less powerful.

2300.   Accurate Classification of Parotid Tumors Based on Histogram Analysis of ADC-maps
Sanam Assili1,2, Anahita Fathi Kazerooni1,3, Mahnaz Nabil1,4, Leila Agha Ghazvini5, Mojtaba Safari1, and Hamidreza Saligheh Rad1
1Quantitative MR Imaging and Spectroscopy Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran, 2Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran, 3Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran, 4Department of Statistics, Tarbiat Modares University, Tehran, Iran, 5Department of Radiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

Accurate discrimination of benign and malignant parotid tumors in morphological MR images is a challenging issue. On one hand there exist large histological variations throughout the tumor, and on the other hand anatomical MR-derived features have low sensitivity in capturing the physiological non-uniformities of parotid tumors. To overcome this problem, in this work, we have explored and compared several quantitative measures extracted from ADC map to find the best parameters in distinguishing benign and malignant parotid tumors, in an automatic classification scheme.

2301.   Clinical evaluation of ZTE skull segmentation
Gaspar Delso1, Mohammad Mehdi Khalighi1, Florian Wiesinger2, and Patrick Veit-Haibach3
1GE Healthcare, Waukesha, WI, United States, 2GE Global Research, Germany, 3University Hospital of Zurich, Switzerland

One of the main challenges of attenuation correction in hybrid PET/MR scanners is the correct identification of bone tissue. A recent development has been the publication of a new bone identification technique, based on 3D radial zero echo time (ZTE) imaging. This sequence provides high-resolution, isotropic images, suitable for bone segmentation, without the need of preparation pulses or multiple echoes, making it a very time-efficient acquisition. The goal of the present study is to compare ZTE bone images of clinical patients with the corresponding CT datasets, obtained using a tri-modality scanner setup.

2302.   K-t BLAST/k-t FOCUSS in real time imaging of the soft palate during speech
Marzena Wylezinska1, Andreia Freitas1,2, Malcolm Birch1, and Marc Miquel1,2
1Clinical Physics, Barts Health NHS Trust, London, United Kingdom, 2William Harvey Research Institute, Queen Mary University of London, London, United Kingdom

The aim of this work was to investigate the performance of k-t BLAST scheme when applied to real-time imaging of speech. We were particularly interested to determine if this method could be used clinically to visualize soft palate motion and velopharyngeal closure during speech. We have also investigated k-t FOCUSS algorithm for reconstruction of dynamic speech data and compared it with commercially available k-t BLAST reconstruction. K-t BLAST scheme is a promising tool to accelerate MRI for speech imaging. K-t FOCUSS reconstruction allowed to improve quality of the images.

2303.   Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus
Han Lv1, Zhenchang Wang1, Zhaohui Liu2, Fei Yan2, Pengfei Zhao1, and Ting Li2
1Beijing Friendship Hospital, Beijing, Beijing, China, 2Beijing Tongren Hospital, Beijing, China

Our results provide insights into the understanding of neural plasticity of PT patients and indicate that a properly chosen frequency band can be more helpful to explore PT-related neural changes.

2304.   Extra-ocular muscle fat fraction in thyroid eye disease
Tilak Das1, Andrew J Patterson1, Paul Meyer2, Rachna Murthy2, and Martin J Graves1
1Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 2Dept of Ophthalmology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom

Thyroid eye disease is an autoimmune disorder of orbital tissues that can cause extra-ocular muscle inflammation and enlargement. Fat infiltration of extra-ocular muscles occurs in patients with chronic disease. Quantification of fat in extra-ocular muscles has not been previously described. The purpose of this study was to evaluate the application of fat fraction measurements to extra-ocular muscles in healthy volunteers and patients with thyroid eye disease. Mean fat fraction was significantly greater in thyroid eye disease patients (p=0.021). This study demonstrates the feasibility of measuring fat fraction in extra-ocular muscles as well as detecting differences between groups.

2305.   Accelerated Multi-Shot Diffusion Imaging in Optic Nerve
Jr-yuan George Chiou1, Bruno Madore1, and Stephan E. Maier1
1Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States

Quantitative MRI of the human optic nerve in vivo is generally quite challenging because of its small size, its uncontrolled motion, and the presence of local field inhomogeneity. Single-shot echo-planar imaging (EPI) is employed to obtain diffusion-weighted images within hundreds of milliseconds, but images often suffer from significant artifacts. In this study, an accelerated multi-shot diffusion imaging was employed to achieve high resolution, speed and geometric fidelity in optic nerve imaging.

2306.   Measurement of the Vitreous Humour Deformation and Strain with Tagged MR Imaging
Ming Li1,2, Paul Gamlin3, Mark S. Bolding4,5, Ronald J. Beyers1, Nouha Salibi1,6, Xiaoxia Zhang1,2, and Thomas S. Denney Jr.1,2
1Auburn University MRI Research Center, Auburn University, Auburn, AL, United States, 2Electrical and Computer Engineering, Auburn University, Auburn, AL, United States,3Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, United States, 4Departments of Radiology, Vision Sciences, and Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States, 5Civitan Functional Neuroimaging Laboratory, University of Alabama at Birmingham, Birmingham, AL, United States,6MR R&D, Siemens Healthcare, Malvern, PA, United States

The vitreous humour undergoes mechanical changes that are thought to be related to a range of pathologies including retinal detachment and are reflected on the motion pattern of the vitreous humour during eye movements. We analyzed the in-vivo dynamics of the vitreous humour under smooth pursuit eye movement, using tagged MRI with a standard head coil in a 7 Tesla scanner. We also propose a method for measuring regional shear strain in the vitreous humour, which does not use assumptions on the geometry of the globe or material properties of the vitreous.

2307.   The effects of Dorzolamide on retinal and choroidal blood flow in a mouse glaucoma model
Saurav B Chandra1, Kaiwalya S Deo1, Eric R Muir1, Jeffrey W Kiel2, and Timothy Q Duong1
1Research Imaging Institute, UT Health Sc. Center, San Antonio, San Antonio, Texas, United States, 2Ophthalmology, UT Health Sc. Center, San Antonio, San Antonio, Texas, United States

Dorzolamide (DZ) is clinically used to treat glaucoma by reducing intraocular pressure, which could affect blood flow to the eye. The goal of this study was to investigate the effect of topical DZ application on retinal and choroidal blood flow in DBA/2J mice, an established mouse model of glaucoma at different stages of severity. DZ was found to induce measurable and sustained effects in choroidal BF and retinal BF at up to 2 hours post DZ application in late stage glaucoma mice.

2308.   High resolution DWI for orbital tumors: 3D turbo field echo with diffusion-sensitized driven-equilibrium (DSDE-TFE) preparation technique
Akio Hiwatashi1, Osamu Togao1, Koji Yamashita1, Kazufumi Kikuchi1, Makoto Obara2, and Hiroshi Honda1
1Radiology, Kyushu University, Fukuoka, Fukuoka, Japan, 2Philips Electronics Japan, Tokyo, Japan

With its insensitivity to field inhomogeneity and high spatial resolution, the 3D DSDE-TFE technique enabled us to discriminate solid tumors from cystic tumors without contrast material.

2309.   Reduced field-of-view imaging with 3D variable flip angle Fast Spin Echo-feasibility in MRI of orbits
Suchandrima Banerjee1, Misung Han2, Weitian Chen1, Christopher P Hess2, Roland Krug2, Ajit Shankaranarayanan1, and Yuval Zur3
1Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 2Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3GE Healthcare, Tirat Carmel, Israel

MRI is moving toward volumetric imaging, because of the flexibility it allows for reformatting a single image volume in any oblique plane and the simplified workflow. Reduced field-of-view (rFOV) capability can enable focused 3D high resolution imaging, even of deep-seated regions, within a short scan time. This work presents an rFOV 3D FSE sequence using outer volume suppression and demonstrates its utility in a challenging application area-MRI of the orbits-in comparison with an existing 2D FSE protocol.

2310.   T1-w SE-PROPELLER to overcome motion and flow artifacts in head and neck imaging
Taihra Zadi1, Mika Vogel2, Magnus Mårtensson3, Piotr A. Wielopolski1, and Aad van der Lugt1
1Department of Radiology, Erasmus University Medical Center, Rotterdam, Zuid-Holland, Netherlands, 2Healthcare Systems, General Electric Healthcare, Hoevelaken, Gelderland, Netherlands, 3Applications and Workflow, General Electric Healthcare, Stockholm, Södermanland, Sweden

Previous studies have shown that T1w SE POPELLER is helpful in the reduction of flow artefacts in the brain, especially in the T1w images post-Gd. An additional advantage of SE-PROPELLER sequence is the possibility to reduce bulk motion artefacts. In this study, the effects of the PROPELLER readout are evaluated in the neck region in patients with head and neck tumors, which is usually degraded by motion and flow artefacts. In this work we have shown that with T1w SE-PROPELLER, motion artefacts can be reduced significantly. Flow artefacts in T1w scans are also minimized in the SE PROPELLER.

2311.   Metal artifact reduction using MAVRIC in the presence of common orthodontic appliances
Jeff A. Kohlmeier1, Heidi A. Edmonson2, Joel P. Felmlee2, David W. Stanley3, Fred J. Regennitter1, and John E. Volz1
1Department of Orthodontics, Mayo Clinic, Rochester, MN, United States, 2Department of Radiology, Mayo Clinic, Rochester, MN, United States, 3GE Healthcare, Rochester, MN, United States

Orthodontic appliances are well known to produce artifact and geometric distortion in MR imaging of the head and neck. The goal of this study was the quantify the extent of susceptibility artifact induced by common orthodontic appliances and to evaluate the utility of MAVRIC for imaging near the appliances. Various appliances configurations were imaged on an anthropomorphic phantom utilizing T2FSE, T1 Cube, T1 MAVRIC and SL MAVRIC sequences. Our results show a large reduction in signal void when comparing MAVRIC to both T2 FSE and T1 Cube sequences for all appliances (51% and 83% reduction respectively). These results suggest that MAVRIC could decrease the frequency of appliance removal for MR imaging and could be used as a problem solving sequence for tissues near the appliance.

2312.   Alterations in Cortical Sensorimotor Connectivity following Complete Cervical Spinal Cord Injury: Evidence from Resting-State fMRI
Akinwunmi Oni-Orisan1, Mayank Kaushal2, Wenjun Li1, B. Doug Ward1, Aditya Vedantam3, Benjamin Kalinosky2, Dana Seslija1, Matthew Budde1, Brian Schmit2, Shi-Jiang Li1, Muqeet Vaishnavi1, and Shekar Kurpad1
1Medical College of Wisconsin, Milwaukee, Wisconsin, United States, 2Marquette University, Milwaukee, Wisconsin, United States, 3Baylor College of Medicine, Houston, Texas, United States

We performed a resting-state functional magnetic resonance imaging (rs-fMRI) study to demonstrate alterations in cortical activation maps in patients with spinal cord injury (SCI). After prepreprocessing of functional data using Analysis of Functional NeuroImages (AFNI) software, region of interest (ROI) based analysis was carried out. A general pattern of decreased functional connectivity in sensorimotor cortex and increased connectivity in thalamus was observed in SCI patients compared to controls. Our results provide evidence of abnormal spontaneous brain activations in humans with SCI suggesting a possible SCI-induced reorganization of cerebral cortex on account of ongoing neural plasticity in the central nervous system.

2313.   Short-term reproducibility of apparent diffusion coefficient and intravoxel incoherent motion parameters in normal head and neck tissues: comparisons of 4b values, 4b values with cardiac gating, and 17 b values
KOUNG MI KANG1 and Seung Hong Choi1
1Radiology, Seoul National Univ. Hospital, Seoul, Seoul, Korea

The objective of this study was to prospectively evaluate short-term test-retest reproducibility of IVIM parameters and apparent diffusion coefficient (ADC) of variable tissue in the head and neck using 4b values, 4b values with cardiac gating and 17b values, respectively. As a result, IVIM DWI using 4bvalues with gating was the most reproducible method in the head and neck in comparison with IVIM DWIs using 4b values or 17 values.

2314.   MiR-155 ablation protects spinal cord (SC) from damage in a mouse model of ischemic SC injury
Anna Bratasz1, Esmerina Tili2,3, Xiaomei Meng2, Jean-Jacques Michaille4,5, Lamia Bouhliqah6, Phillip G Popovich7, Cynthia Mcallister8, D Michele Basso9, José J Otero10, Claudia Kirsch11, Richard Burry7, Kimerly A Powell1, Peter Mohler12, Carlo M Croce4, and Hamdy Awad2
1Small Animal Imaging Core, The Ohio State University, Columbus, Ohio, United States, 2Department of Anesthesiology, The Ohio State University, Ohio, United States,3Department of Molecular Virology, The Ohio State Univeristy, Ohio, United States, 4Department of Molecular Virology, The Ohio State University, Ohio, United States, 5Université de Bourgogne, Dijon, France, 6Department of ENT, The Ohio State University, Ohio, United States, 7Department of Neuroscience, The Ohio State University, Ohio, United States,8Nationwide Children Hospital, Ohio, United States, 9School of Health and Rehabilitation Sciences, The Ohio State University, Ohio, United States, 10Department of Pathology, The Ohio State University, Ohio, United States, 11Department of Radiology, The Ohio State University, Ohio, United States, 12Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Ohio, United States

MiR-155 ablation was evaluated for its protective effect on ischemic cord injury (SC) in a mouse model of thoraco-abdominal aortic aneurysm (TAAA) repair. MR imaging was used for monitoring the paralysis event in wild type and miR-155 knockout mice. MiR-155-/- mice resulted in reduced number and delayed paralysis events. There was a strong correlation between edema volume and T2 relaxation time values of the SC grey matter in paralyzed versus non-paralyzed mice. Edema was correlated with histological observation of gray matter damage. We believe that reducing miR-155 upregulation after TAAA may be useful for reducing paralysis after surgery.

2315.   Assessment of Cervical Spinal Cord Injuries with Readout-Segmented Multi-shot (RESOLVE) Diffusion Tensor Imaging and Fiber Tractography
Chen-Te Wu1, Cheng-Chih Liao2, Chung-Lin Yang2, Jiun-Jie Wang3, Ching-Po Lin4, and Shih-Tseng Li2
1Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan, 2Departments of Neurosurgery, Chang Gung Memorial Hospital & Chang Gung University, Taiwan, 3Department of Medical Imaging and Radiological Science, Chang Gung University, Taiwan, 4Brain Connectivity Lab, Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan

RESOLVE-DTI can help to assess the severity of cervical spinal cord injuries and provide reproducible quantitative measurements with limited distortion in a clinically acceptable scan time. With RESOLVE-DTI, severe and mild grades of cervical spinal cord injuries can be discriminated against the imaging bias of spinal stenosis and spinal cord edema.

2316.   Injury alters the intrinsic functional connectivity network in spinal cord of monkeys
Li Min Chen1,2, Arabinda Mishra1,2, Feng Wang1,2, Pai-Feng Yang1,2, and John C. Gore1,2
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States

Resting state fMRI has shown that intrinsic functional connectivity networks may be detected in the spinal cord of humans and anesthetized monkeys. The functional relevance of these networks, however, remains to be determined. One way to address this question is to modulate the network and then correlate the changes with behavioral and functional outcomes. In this study we examined the effects of unilateral spinal cord injury on the inter-regional correlation strengths of resting state fMRI signals between spinal horns of gray matter in spinal segments above or below the injury level.

2317.   Robust diffusion-prepared neurography of the complete brachial plexus facilitated by an optimized shimming strategy.
Jos Oudeman1, Bram F Coolen1, Camiel Verhamme2, Mario Maas1, Andrew Webb3, Gustav J Strijkers4, and Aart J Nederveen1
1Radiology, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands, 2Neurology, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands, 3Radiology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 4Biomechanical engineering and physics, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands

New imaging methods of the brachial plexus are believed to assist in diagnosis of immune mediated diseases. In this study, we optimized a 3D diffusion prepared iMSDE sequence to include the full brachial plexus and shoulders. Although giving excellent contrast of the nerves, poor fat-suppression and a poor signal to noise ratio due to B0 inhomogeneities are often a problem. To overcome this problem we tested the use of a neck pillow filled with pineapple juice. Secondly we compared image based shimming to volume shimming. The use of the pillow in combination with IB-shimming showed the best result.

2318.   Reproducibility of resting state spinal cord networks at 7 Tesla
Robert L Barry1,2, Baxter P Rogers1,2, Seth A Smith1,2, and John C Gore1,2
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States

A recent 7 Tesla study provided evidence for the existence of resting state networks in the human spinal cord by demonstrating inter-subject reproducibility of temporal correlations between ventral (motor) gray matter horns and between dorsal (sensory) gray matter horns in healthy subjects. In this abstract we build upon these findings and present measurements of within-subject reproducibility of within-slice spinal cord functional connectivity between ventral horns and between dorsal horns. This work will be important for future studies that rely upon these measurements to gain insight into how these networks change due to aging, injury, or disease.

2319.   Endothelial nitric-oxide synthase overexpression rescues cerebral blood flow and cerebrovascular reactivity in diabetic brain
Saurav B Chandra1, Sumathy Mohan2, Preethi Janardhanan2, Kaiwalya S Deo1, Eric R Muir1, and Timothy Q Duong1
1Research Imaging Institute, UT Health Science Center, San Antonio, TX, United States, 2Pathology, UT Health Sc. Center, San Antonio, TX, United States

Reduced bioavailability of nitric oxide plays a crucial role in endothelial dysfunction in diabetes. The goal of this study was to investigate the effect of eNOS overexpression on cerebral blood flow (CBF) and cerebrovascular reactivity (CR) in diabetic mice, eNOS-overexpressed (TgeNOS) mice, Akita diabetic (Ins2 Akita) mice, and a genetic cross of TgeNOS⨂Ins2 Akita. We hypothesized that eNOS overexpression rescues CBF and CR dysfunction in the diabetic brain.

2320.   Measuring brain lactate with 1H-MRS during hypoglycemia in humans; preliminary results
Evita C. Wiegers1, Hanne M.M. Rooijackers2, Cees J. Tack2, Arend Heerschap1, Bastiaan E. de Galan2, and Marinette van der Graaf1,3
1Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands, 2Internal Medicine, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands, 3Pediatrics, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands

The effect of hypoglycemia on brain lactate content was studied with 1H-MRS. Difference spectra, acquired with an interleaved J-editing (MEGA) semi-LASER sequence, were used to determine brain lactate levels during stable euglycemic and hypoglycemic conditions. Furthermore, arterial blood samples were taken to determine arterial lactate and glucose levels. The preliminary results, obtained in healthy volunteers, suggest that increased plasma lactate levels during hypoglycemia are not accompanied by an increase in lactate content in the brain.

2321.   Diffusion tensor imaging analysis of presbycusis using voxel-based method
Fei Gao1, Guangbin Wang1, Bin Zhao1, Wen Ma2, Muwei Li3, Fuxin Ren1, Bo Liu1, and Weibo Chen4
1Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, 2The Central Hospital of Jinan City, Shandong University, Jinan, China, 3College of Electronics and Information Engineering, Sichuan University, Chengdu, China, 4Philips Healthcare, Shanghai, China

This DTI-based study revealed presbycusis-related integrity change of white matter along auditory pathway as well as several language-related areas. It is believed that our findings could be important for exploring the real imaging evidence of presbycusis and could complement to studies using different imaging modalities or different subject populations.