Alicia Cronin^1,2, Patrick Liebig³, Sarah Detombe⁴, Neil Duggal⁴, and Robert Bartha^1,2
1Medical Biophysics, University of Western Ontario, London, ON, Canada, ²Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, ON, Canada, ³Siemens Healthineers, Erlangen, Germany, ⁴Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, London, ON, Canada

Degenerative cervical myelopathy (DCM) is one of the most common forms of spinal cord dysfunction. Predicting functional recovery after surgery remains elusive. Pathophysiological mechanisms, like ischemia and hypoxia in the spinal cord, could impact recovery after surgery. Chemical Exchange Saturation Transfer (CEST) produces image contrast based on the rate of exchange of amine and amide protons. This exchange rate is dependent on tissue pH, creating a pH-weighted contrast. CEST imaging in the spinal cord incorporating respiratory correction could be used to examine tissue pathology caused by hypoxia in DCM and other spinal cord injuries.

Haimei Cao¹, Xiang Xiao¹, Jun Hua^2,3, Guanglong Huang⁴, Xiaodan Li¹, Wenle He¹, Jie Qin¹, and Yuankui Wu^1
1Department of Medical Imaging, Nanfang Hospital, Southern Medical University, Guangzhou, China, ²Neurosection, Division of MRI Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ³F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China

Glioma grading is vital for planning therapeutic approaches and assessing prognosis and response to treatment. Advanced MR imaging provides physiological information of brain tumors in microcirculation, cell and molecular levels, thus improving the preoperative prediction of glioma grade. In this study, we studied the value of combined inflow-based vascular-space-occupancy (iVASO) MR imaging and diffusion-weighted imaging (DWI) in preoperative prediction of gliomas grade. The results showed that combined iVASO and DWI improved the diagnostic performance of glioma grading. This suggests that the combined application of iVASO and DWI might be used as part of the routine brain tumor imaging protocol.

Priyanka Bhat¹, S Senthil Kumaran², Achal K Srivastava¹, and Vinay Goyal^3
1Neurology, AIIMS, Delhi, India, ²Nuclear Magnetic Resonance, AIIMS, Delhi, India, ³Neurology, Medanta, The Medicity, Gurgaon, India

Parkinson’s disease (PD) is  charcterized by progressive degenration of dopaminergic neurons in substantia nigra. This leads to motor symptoms like bradykinesia with rigidity and tremor. PD patients also experience difficulty in traversing through narrow spaces. Indicating towards altered motor execution and planning and decision making. This study was aimed thus to explore the progressively deteriorating brain connectivity in PD. Functional connectivity was observed to be altered with duration of disease.

Eun-Jung Choi¹, Koung Mi Kang², Woojin Jung¹, Jongho Lee¹, Seung Hong Choi², and Yong Hwy Kim^3
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of, ²Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, ³Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea, Republic of

We investigated the impairment in the optic radiations affected by the anterior visual pathway compression using the diffusion tensor imaging (DTI), and neurite orientation dispersion and density imaging (NODDI). The results were correlated with the visual field impairment score (VFIS), which assesses the function of posterior visual pathway. The DTI and NODDI parameters in the optic radiations were significantly correlated with postoperative visual field improvement as well as preoperative visual field impairment in patients with the compression of optic chiasm. The study demonstrated the anterior visual pathway compression influences the visual field defect of the posterior visual pathway.

Laleh Eskandarian^1,2, Safak Parlak³, Onur Afacan^4,5, Ceren Günbey⁶, Nesibe Gevher Ertuğrul⁶, Banu Anlar⁶, and Kader Karli Oguz^2,3
1Neuroscience Department, Bilkent University, Ankara, Turkey, ²National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey, ³Faculty of Medicine, Department of Radiology, Hacettepe University, Ankara, Turkey, ⁴Department of Radiology, Boston Children’s Hospital, Boston, MA, United States, ⁵Department of Radiology, Harvard Medical School, Boston, MA, United States, ⁶Department of Pediatrics, Hacettepe University, Ankara, Turkey

Metachromatic leukodystrophy (MLD) is a dysmyelinating autosomal recessive lysosomal storage disease. Conventional T2WI may not show the disease involvement accurately, especially in early phases of the disease where a bone marrow transplant can be a treatment option. Therefore we used Myelin Water Fraction (MWF) and Diffusion Tensor Imaging to investigate WM in patients with MLD. MWF and metrics derived from DTI, especially fractional anisotropy (FA), showed diffuse abnormality in WM and were significantly correlated.  These imaging techniques can better assess involvement of the cerebral WM in patients with MLD.

Shin Tai Chong¹, Xinrui Liu², Hung-Wen Kao³, Chien-Yuan Eddy Lin⁴, Sanford PC Hsu⁵, and Ching-Po Lin^1
1Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, ²Department of Neurosurgery, First Hospital of Jilin University, Jilin, China, ³Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ⁴GE Healthcare, Taipei, Taiwan, ⁵Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan

We hypothesized that the Neurite Orientation Dispersion and Density Imaging (NODDI)-based tractography could improve the reconstruction of the fiber tracts that by tracking through regions of peritumoral edema. In visual comparison with diffusion tensor imaging (DTI), we found that NODDI-based tractography of the corticospinal tract (CST) showed higher sensitivity and specificity in the region of peritumoral edema. The NODDI-based tractography was validated in two patients with tumors resected for five years. With this technique, neurosurgeons may develop better surgical planning to maximize tumor resection and minimize functional loss.

Yan Xie¹, Shihui Li¹, Nanxi Shen¹, Weiyin Vivian Liu², and Wenzhen Zhu^1
1Department of Radiology, Tongji Hospital, Tongji Medical College, HUST, Wuhan, China, ²MR Research, GE Healthcare, Beijing, China

The purpose of this study was to evaluate the efficacy of conventional diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM) imaging and diffusion kurtosis imaging (DKI) in assessing IDH1 mutation status and MGMT promoter methylation status in gliomas. In lower-grade gliomas, diffusion MRI parameters were able to significantly distinguish the mutation status of IDH1 and the methylation status of MGMT promoter, which is helpful for predicting prognosis and sensitivity to alkylating chemotherapeutic agents of patients. However, in glioblastomas, there was no significant difference between mutant and wild-type IDH1 as well as methylation and unmethylation status of the MGMT promoter.

Weike Zeng¹ and Mengzhu Wang^2
1Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China, ²MR Scientific Marketing, Siemens Healthcare, Guangzhou, China

This study aimed to demonstrate the feasibility of neurite orientation dispersion and density imaging (NODDI) for in exploring the pathological mechanism of cognitive impairment in RI compared to DTI. We evaluated the differences of all diffusion parameters between patients with and without cognitive decline confirmed by Montreal Cognitive Assessment (MoCA) scores, as well as the correlation between diffusion maps and cognitive decline. Results demonstrated that NODDI was more sensitive than DTI in detecting cognitive decline in patients with radiation-induced brain injury. Cognitive decline in radiation-induced brain injury was associated with the reduction of neurite density

Beatrice Federica Luciani¹, Francesca Saviola¹, Luca Zigiotto^2,3, Stefano Tambalo¹, Domenico Zacà¹, Lisa Novello¹, Silvio Sarubbo^2,3, and Jorge Jovicich^1
1CIMeC Center for Mind/Brain Sciences, University of Trento, Rovereto (Trento), Italy, ²Department of Neuroscience, Division of Neurosurgery, S.Chiara Hospital, APSS, Trento, Italy, ³Structural and Functional Connectivity Lab, S.Chiara Hospital, APSS, Trento, Italy

In glioma patients, tumor lateralization and grade can critically affect the underlying brain functional connectivity. Little is known about how functional connectivity changes after surgical glioma resection. We employed graph theory analysis to investigate post-surgery longitudinal reorganization of functional networks at global (network-wide) and local (nodal) level. We found that left-lateralized and/or high-grade gliomas show reduced segregation and centrality properties over time, compared to right-lateralized and low-grade gliomas. Our results suggest the importance of pre-surgical mapping of hub networks like the default mode network, in addition to visual, motor and language networks.

Augusto Lio M. Goncalves Filho^1,2, Azadeh Tabari^1,2, Chanon Ngamsombat³, Ilena George⁴, Stephen F. Cauley², Wei Liu⁵, Daniel N. Splitthoff⁶, Wei-Ching Lo⁷, Pamela W. Schaefer¹, Otto Rapalino¹, Eric C. Klawiter⁴, John Conklin^1,2, and Susie Y. Huang^1,2
1Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, ²Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ³Department of Radiology, Siriraj Hospital, Bangkok, Thailand, ⁴Department of Neurology, Massachusetts General Hospital, Boston, MA, United States, ⁵Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, ⁶Siemens Healthcare GmbH, Erlangen, Germany, ⁷Siemens Medical Solutions Inc., Boston, MA, United States

The central vein sign (CVS) and paramagnetic rims are imaging signs specific for demyelinating lesions in multiple sclerosis (MS) that can be detected using high-resolution susceptibility-weighted imaging (SWI) and FLAIR sequences. We developed an optimized protocol for fast, comprehensive evaluation of demyelinating lesions including highly accelerated Wave-CAIPI SWI and FLAIR. In 65 patients undergoing evaluation for demyelinating disease, we found that 72% of MS and CIS patients had at least one CVS, and 45% showed at least one paramagnetic rim. The application of highly accelerated Wave-SWI and Wave-FLAIR may improve the characterization of MS lesions in clinically feasible acquisition times.

Haodan Dang¹, Ruimin Wang¹, Jiajin Liu¹, Huaping Fu¹, Mu Lin², Jiahe Tian¹, Jinming Zhang¹, and Baixuan Xu^1
1Department of nuclear medicine, Chinese PLA General Hospital, Beijing, China, ²2. MR Collaboration, Diagnostic Imaging, Siemens Healthcare, Shanghai, China

The purpose of this study was to evaluate the diagnostic potential of decision-tree model of diffusion kurtosis imaging (DKI) and 11C-methionine (11C-MET) PET imaging, for the differentiation of radiotherapy injury from glioblastoma recurrence using integrated PET/MR. Eighty-six glioblastoma cases with suspected lesions after radiotherapy were retrospectively enrolled. Compared to models of DKI-alone (AUC=0.85) and PET-alone (AUC=0.89), the combined model demonstrated the best diagnostic accuracy (AUC=0.95). The decision-tree model has the potential to further increase diagnostic accuracy for discrimination between radiotherapy injury and glioblastoma recurrence. 11C-MET PET/MR may thus contribute to the management of glioblastoma patients with suspected lesions after radiotherapy.

qianwen li¹, juan Wei², and jie Lu^1
1Xuanwu Hospital，Capital Medical University, Beijing, China, ²GE Healthcare, Beijing, China

Quantitative Susceptibility Mapping (QSM), a newly developed quantitative and accurate measurement method that can be used to detect iron-related motor cortex alterations in patients of Amyotrophic lateral sclerosis (ALS) that may be relevant to pathologic changes.

Ying Cui¹, Tian-yu Tang², and Shenghong Ju^1
1Department of Radiology, Zhongda hospital, Southeast University, Nanjing, China, ²Southeast University, Nanjing, China

This study combined the resting-state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI) to explore whether the interhemispheric coordination is altered in type 2 diabetes (T2DM). Results showed that the occipital lobe was disrupted in both functional and anatomic connections and such alteration is strongly associated with endocrine parameters, especially for insulin resistance.

Yuankui Wu¹, Wenle He^1,2, Wensheng Wang², Jun Hua^3,4, Xiang Xiao¹, Xiaomin Liu¹, Yikai Xu¹, and Yingjie Mei^5
1Department of Medical Imaging, Nanfang Hospital, Southern Medical University, Guangzhou, China, ²Department of Radiology, Guangdong 999 Brain Hospital, Guangzhou, China, ³Neurosection, Division of MRI Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁵Philips healthcare, Guangzhou, China

Accurate prediction of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status preoperatively is important. DSC-MRI can predict MGMT promoter methylation status in glioblastomas but not in lower-grade gliomas. Inflow-based vascular-space-occupancy (iVASO), a novel perfusion technique without the need for exogenous contrast agents, emphasizes the perfusion blood volume in arteries and arterioles. In this study, the predictive ability for MGMT promoter methylation status of iVASO histogram features was investigated. The results showed that iVASO-based histogram features accurately predicted the methylation status of MGMT promoter in  gliomas. This suggests that iVASO may be a promising noninvasive imaging tool in predicting MGMT promoter methylation.

Shihui Zhou^1,2, Huilou Liang^2,3, Yuchao Liang⁴, Siqi Cai^1,2, Chunxiang Jiang^1,2, Rong Xue^2,3, Lei Wang⁴, and Lijuan Zhang*^1
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, ²University of Chinese Academy of Sciences, Beijing, China, ³State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, ⁴Neurosurgery, Beijing Tiantan Hospital of Capital Medical University, Beijing, China

Vein density and oxygen extraction fraction were quantified in brains with glioma using a susceptibility-based approach at 7T. Brains with low grade glioma featured more extensive areas with significant difference in vein density and OEF between the homotopic ROIs that mainly involve fronto-parietal areas and basal ganglia, in contrast to brains with high grade glioma with the differential vein density and OEF distribution mainly involving bilateral thalami. The inter-homotopic measurements of vein density and OEF were significantly correlated, suggesting that the oxygen metabolism malfunction in brains with high grade glioma might be partially ascribed to the altered venous distribution.

Jason Langley¹, Sana Hussain², Daniel E Huddleston³, Ilana Bennett⁴, and Xiaoping P Hu^1,2
1Center for Advanced Neuroimaging, University of California Riverside, Riverside, CA, United States, ²Department of Bioengineering, University of California Riverside, Riverside, CA, United States, ³Department of Neurology, Emory University, Atlanta, GA, United States, ⁴Department of Psychology, University of California Riverside, Riverside, CA, United States

In mild cognitive impairment, hyperphosphorylated tau proteins and tau inclusions first appear in the locus coeruleus and transentorhinal cortex and spread to other brain regions, including the thalamus. Locus coeruleus axons project to the thalamus via the central tegmental tract (CTT).  Relative to APOE-ε4 negative subjects, a decrease in MD (p=0.038) and an increase in ficvf (p=0.007) was seen in the CTT of APOE-ε4 positive subjects. In the APOE-e4 positive group, CTT microstructural measures were positively correlated with thalamus tau-PET SUVR but no correlations between CTT microstructure and tau-PET SUVR were observed in the APOE-ε4 negative group.

Raphiel Jamale Murden¹, Deqiang Qiu², and Benjamin B Risk^2
1Biostatistics and Bioinformatics, Emory University, Atlanta, GA, United States, ²Emory University, Atlanta, GA, United States

Canonical Joint and Individual Variation Explained (CJIVE) provides a method for jointly analyzing multi-block datasets collected from the same individuals. We apply this method to measures of brain morhometry and cognition from a sample of older adults. We found latent patterns of joint variation across data types which were statistically associated  with diagnoses of Alzheimer's Disease and mild cognitive impairment. We also found that the unique patterns of variation within each data type were not associated with diagnoses. 

Madhura Ingalhalikar¹, Sumeet Shinde¹, Arnav Karmarkar¹, Archith Rajan¹, Rangaprakash D², and Gopikrishna Deshpande^3
1Symbiosis Centre for medical image analysis, Symbiosis international university, Pune, India, ²Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, ³Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States

Functional MRI connectivity based analysis that ranges between simple univariate methods to complex deep-learning pipelines has been employed to differentiate autistic patients from healthy controls on benchmark datasets such as ABIDE. However, the variability induced via multi-site acquisition of data may perturb the underlying prediction model with undesirable consequences. We illustrate that statistical elimination of scanner effects using COMBAT harmonization yields better results and also facilitates in gaining insights into the discriminative connectivity patterns that emerge post harmonization and which correlate with clinical markers.

Alexa Haeger^1,2,3, Michel Bottlaender^1,4, Julien Lagarde^4,5,6, Renata Porciuncula Baptista¹, Cécile Rabrait-Lerman¹, Volker Luecken^2,3, Jörg Bernhard Schulz^2,3, Alexandre Vignaud¹, Marie Sarazin^4,5,6, Kathrin Reetz^2,3, Sandro Romanzetti^2,3, and Fawzi Boumezbeur^1
1BAOBAB, CNRS, Paris-Saclay University, CEA-NeuroSpin, Gif-sur-Yvette, France, ²Department of Neurology, RWTH Aachen University, Aachen, Germany, ³JARA-BRAIN Institute of Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH, Julich, Germany, ⁴BioMaps, CNRS, Inserm, Paris-Saclay University, CEA-SHFJ, Orsay, France, ⁵Neurology of Memory and Language, GHU Paris Psychiatrie & Neurosciences, Sainte-Anne Hospital, Paris, France, ⁶Université de Paris, Paris, France

Deficits in brain cells’ homeostasis and metabolism are suspected to occur ahead of the atrophy observed throughout the brain of AD patients with potential interactions between Amyloid/Tau deposits and the Na/K-pump activity leading to increased cerebral sodium concentrations. Yet this increase remains to be confirmed. We present a multimodal imaging study combining structural ¹H-MRI, quantitative  ²³Na MRI at 7T in association with Tau- and Amyloid-PET. We show that total sodium concentration is increased in multiple brain regions in AD compared to cognitively healthy controls, and that these changes are more strongly correlated with local Tau- than Amyloid-loads.

Tracy Ssali^1,2, Lucas Narciso^1,2, Matthais Günther³, Frank Prato^1,2, Udunna Anazodo^1,2, Elizabeth Finger⁴, and Keith St Lawrence^1,2
1Lawson Health Research Institute, London, ON, Canada, ²Department of Medical Biophysics, Western University, London, ON, Canada, ³Fraunhofer Institute for Medical Image Computing MEVIS, Bremen, Germany, ⁴Department of Clinical Neurological Sciences, Western University, London, ON, Canada

Recent advances in the understanding of frontotemporal dementia (FTD) and subsequently, the development of novel disease modifying treatments, has stimulated the need for tools to assess treatment efficacy. While perfusion imaging by arterial spin labeling (ASL) is an attractive approach, its sensitivity to detect longitudinal changes in perfusion in dementia patients remains unknown. Longitudinal variability in perfusion was assessed on a voxel-by-voxel basis over a month. Power analysis revealed ASL has the sensitivity to longitudinal changes as low as 7-8%. These results highlight the potential of ASL for detecting longitudinal changes in FTD populations.