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

Electronic Poster Session • Functional MRI (Neuro)
3899 -3910 Preclinical fMRI
3911 -3930 fMRI Methods
3931 -3947 fMRI: Bold Physiology & Multimodal Imaging
3948 -3968 Functional Connectivity Materials & Applications

Note: The videos below are only the slides from each presentation. They do not have audio.


Tuesday 2 June 2015
Exhibition Hall 16:00 - 17:00

  Computer #  
3899.   1 Quantification of changes in resting state connectivity in monkey SI cortex following spinal cord injury
Arabinda Mishra1, Feng Wang1, John C Gore1, and Chen Min Li1
1Radiology, Vanderbilt University, Nashville, TN, United States

Spinal cord is primarily responsible for transmitting sensory and motor information to and from the brain. Disruptions following injury on the spinal cord affect the functional integrity of somatic sensory networks. This study aims to determine whether the disruption of afferent inputs from the cervical spinal cord alter the fine - scale functional connectivity between sub-regions of SI cortex in the resting state. We performed an ROI based analysis of resting state BOLD MRI signals obtained in pre- versus post- lesion conditions in anesthetized squirrel monkeys at 9.4T to quantify the inter-regional functional connectivity differences between the sub-regions of the SI cortex.

3900.   2 Neurophysiological and neuroenergetic basis of spontaneous BOLD signal fluctuations in resting-state fMRI connectivity maps - permission withheld
Peter Herman1, Basavaraju G. Sanganahalli1, Daniel Coman1, Hal Blumenfeld2, Lihong Jiang1, Douglas L. Rothman1,3, and Fahmeed Hyder1,3
1Diagnostic Radiology, Yale University, New Haven, Connecticut, United States, 2Neurobiology, Yale University, New Haven, Connecticut, United States,3Biomedical Engineering, Yale University, New Haven, Connecticut, United States

Resting-state fMRI (R-fMRI) is powerful for mapping networks. Since oscillations in metabolic/neural events are linked to R-fMRI networks and studies suggest that absolute metabolic/neural baseline interacts with evoked/spontaneous signals, we measured blood flow, neural activity, glucose oxidation, glutamatergic neurotransmission, and BOLD in relation to two states. Fluctuations in metabolic/neural activities underlying connectivity maps, regardless of the state, represented at most 5% of the total baseline metabolic/neural level. Functional correlation density (FCD) maps, not seed-based correlation maps, showed significant alteration between the states in accord with other absolute measures of states, signifying the importance of FCD and absolute baseline in R-fMRI.

3901.   3 Default Mode Network Abnormality in ADHD Rat Model
Sheng-Min Huang1, Wei-Cheng Lee1, Kung-Chu Ho2, and Fu-Nien Wang1
1Department of Biomedical Engineering & Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Nuclear Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan

Resting state functional MRI is an emerging neuroimaging method, examining the connectivity of brain neural circuits. In this work a seed-based analysis was carried out to compare the resting state network between normal (WKY) and ADHD rat model (SHR). Results show that ADHD rat presented a network contains caudate putamen region but WKY didn't. This difference may be tied to the symptoms of ADHD since putamen is involved in the regulation of motor behavior and caudate nucleus is related to social behavior.

3902.   4 Anesthesia level modulate brain activity and connections in Monkey
Zhentao Zuo1, Xudong Zhao1, Yifan Miao2, Shuo Shen1, Zuxiang Liu1, and Yuanye Ma1
1Chinese Academy of Sciences, Institute of Biophysics, Beijing, Beijing, China, 2State Key lab of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, Beijing, China

Resting state-fMRI (rs-fMRI) allows studying aesthesis status through functional connectivity (FC) and amplitude low-frequency fluctuation (ALFF), as well as the mechanisms of different neurological diseases. Several monkeys scanner with different anesthesia depths underlying rs-fMRI were scanned to explore the variation of the monkey brain FC patterns and brain region neuron fluctuation. We found different drip concentrations will affect the monkey anesthesia depth. Higher concentration suppresses more neurons activity and also decreases the connections between different cerebral hemispheres and surround regions. It also opened a new method to explore how the intrinsic network created, and whether the connectome dependent on the neuron activity.

3903.   5 Deep Anesthesia Provokes Dissimilar Resting State Connectivities in ADHD Rat Model and Normal Control
Sheng-Min Huang1, Wei-Cheng Lee1, Kung-Chu Ho2, and Fu-Nien Wang1
1Department of Biomedical Engineering & Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Nuclear Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan

In this abstract the resistance to isoflurane anesthesia between ADHD model (SHR) and normal control (WKY) was compared by using resting state functional MRI. A different distribution of remaining network under high dose anesthesia was found. WKY group tends to preserve the frontal region of brain, while SHR group keep the central region. Since we can speculate that the connections in high anesthesia level are very fundamental networks, these basic differences between SHR and WKY may be one of the origins of functional abnormality in ADHD rat.

3904.   6 Predicting Dogs’ Training Ease and Behavior using their Neural Responses to Discriminative Odors
Tuo Shi1, Oleg Pustovyy2, Yun Wang1, Paul Waggoner3, Ronald Beyers1, Jessica Fleming4, Paul Hammond4, Edward Morrison2, Thomas S. Denney Jr.1,5, Vitaly Vodyanoy2, and Gopikrishna Deshpande1,5
1AU MRI Research Center, Dept. of Electrical & Computer Engineering, Auburn University, Auburn, AL, United States, 2Dept. of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, AL, United States, 3Canine Detection Research Institute, Auburn University, Auburn, AL, United States, 4iK9 LLC, Auburn, AL, United States, 5Dept. of Psychology, Auburn University, Auburn, AL, United States

Humans have long made use of olfactory detection capabilities of dogs. Training dogs to use those capabilities can be expensive due to the manpower and time involved. Therefore, predicting the training ease and behavioral of working dogs before their recruitment will be beneficial. We explored the canine olfactory system using functional MRI and correlated the canine behavior with imaging metrics derived from activation to discriminative odors, to predict dogs’ training ease and behavior. We found the discriminative odorant stimulus lead to higher activity in olfaction-related and higher order brain areas, also were significantly correlated with integrated behavior and training ease.

3905.   7 Auditory Cortex Modulates the Midbrain Response Selectivity to Behaviorally Relevant Sounds
Jevin W. Zhang1,2, Patrick P. Gao1,2, Shu-Juan Fan1,2, Dan H. Sanes3, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, 3Center for Neural Science, New York University, New York, NY, United States

The auditory cortex (AC) is the source of one of the largest inputs to the inferior colliculus (IC). Normal IC exhibits stronger BOLD response to forward vocalizations than to the temporally inverted one. But this responses selectivity to behaviorally relevant sound requires AC inputs. After bilateral AC ablation, the BOLD response difference between the two vocalizations in the IC was diminished. In the unilateral (right side) AC ablation animals, the BOLD response difference between the two vocalizations in the ablation (right) side was negligible while the contralateral (left) ECIC still showed a stronger response to the forward vocalization.

3906.   8 Deep Brain Stimulation of the Rodent Nucleus Accumbens Recruits Subcortical Limbic Networks
Daniel Albaugh1,2, Garret Stuber3, and Yen-Yu Ian Shih4
1Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States, 2Biomedical Imaging Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States, 3Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States, 4BRIC, Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States

Deep brain stimulation (DBS) of the nucleus accumbens is a promising therapy for a wide variety of intractable neuropsychiatric disorders. Here, we have employed an animal model of DBS, with simultaneous fMRI, to decipher the neural circuitry modulated by accumbens DBS.

3907.   9 Auditory and Visual Cortices Differentially Modulate Auditory Responses in the Midbrain
Patrick P. Gao1,2, Jevin W. Zhang1,2, Shu-Juan Fan1,2, Dan H. Sanes3, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, HKSAR, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, HKSAR, China, 3Center for Neural Science, New York University, New York, NY, United States

The cortex is commonly thought of as the site at which ascending projections from all sensory modalities are integrated, yet cortical feedback to subcortical nuclei modulates early information processing. Here, we demonstrate that descending inputs from both auditory and visual cortex are integrated in the auditory midbrain. Using BOLD fMRI to measure sound-evoked responses throughout the auditory midbrain, we show that auditory cortical input normally suppresses the gain of midbrain response, while visual cortical input increases the gain. Our results demonstrate the large-scale influence of cortical projections from more than one sensory modality, demonstrating that while ascending integration occurs in cortex, descending integration occurs in the brainstem.

3908.   10 High pulse rate acoustic stimulation reduces fMRI responses in the auditory thalamus and cortex of chronic noise exposed rats
Condon Lau1, Jevin W Zhang2, and Ed X Wu2
1Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR, Hong Kong, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong SAR, Hong Kong

Long-term acoustic noise exposure at moderate sound pressure levels (SPLs) (within occupational limits) can be detrimental to speech intelligibility by altering its spectrotemporal representation in the auditory system. To test this, we performed fMRI on adult rats exposed to 65dB SPL noise for two months. The results show noise exposure reduces fMRI signals in the auditory thalamus and cortex. The reduction is greater during 10 than 5Hz pulse rate acoustic stimulation. These findings are important for speech processing, which depends on accurate processing of sounds with a wide spectrum of rates.

3909.   11 Dose-dependent effects of sevoflurane on temporal distribution of BOLD responses to somatosensory stimulation in rats
Tomokazu Tsurugizawa1,2, Yukari Takahashi1, Akihiko Kitamura1,3, and Fusao Kato1
1Jikei University School of Medicine, Tokyo, Japan, 2NeuroSpin/CEA, Gif-sur-Yvette, Essone, France, 3Ajinomoto Co. Inc., Kawasaki, Japan

We aimed to investigate the dose-dependence of sevoflurane on BOLD responses in the upper layer (layer 1-3) and in the lower layer (layer 4-6) of the somatosensory cortex to electrical stimulation in the hindpaw. The BOLD responses in the upper layer were greater than those in the lower layer. The estimation of hemodynamic response indicates that time-courses of BOLD responses were dependent on the concentration of sevoflurane, indicating the disturbance of neurovascular coupling by sevoflurane dos-dependently.

3910.   12 500 ms temporal and 750 µm spatial inplane resolution for whole-brain fMRI applications in the macaque at 7T
Dávid Z Balla1, Rolf Pohmann1, Shajan G1, Philipp Ehses1, Arno Nauerth2, Thomas Steudel1, Yusuke Murayama1, Axel Oeltermann1, Matthias H Munk1, Hellmut Merkle1, Michael Beyerlein1, Henry C Evrard1, Nikos K Logothetis1, and Klaus Scheffler1
1Max Planck Insitute for Biological Cybernetics, Tübingen, Germany, 2Bruker Biospin GmbH, Ettlingen, Germany

We developed fast MRI methods facilitating concurrent electrophysiological recordings and fMRI with high spatio-temporal resolution (500ms / 750µm) and full brain coverage in macaques. The significant improvements in MR signal sampling efficiency without and with the use of parallel imaging are demonstrated by presenting activation maps and time-courses of fMRI experiments using a simple visual stimulation paradigm.

Tuesday 2 June 2015
Exhibition Hall 16:00 - 17:00

  Computer #  
3911.   13 Accelerated Neonatal fMRI using Multiband EPI
Anthony N. Price1,2, Lucilio Cordero-Grande1,2, Shaihan J. Malik1,2, Maryam Abaei1, Tomoki Arichi1, Emer J. Hughes1, Daniel Rueckert3, A. David Edwards1, and Joseph V. Hajnal1,2
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom, 3Biomedical Image Analysis Group, Imperial College London, London, United Kingdom

Simultaneous multi-slice EPI acquisitions using multiband (MB) excitation have recently been demonstrated to provide high resolution fMRI data with significantly reduced acquisition time, sufficient enough to directly determine cardiac and respiratory influences from spontaneous activation in the brain. These have mainly been applied to adult subjects, but here we demonstrate MB EPI applied to preterm infants with cardiac rates exceeding 160 bpm. Resting state fMRI data collected with MB factors of 9 demonstrate it is possible to distinguish the neonatal cardiac physiology from activations in resting state networks.

3912.   14 COMPARISON OF MULTI-BAND MULTI-ECHO AND MULTI-ECHO AT 3T
Vincent Jansen1, Rasim Boyacioglu1, Jenni Schulz1, and David G Norris1,2
1Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands, 2University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany

Following a recent implementation1 of a Multi-Band2 Multi-Echo3 (MBME) sequence at 7T for resting state fMRI that showed improved sensitivity, the potential benefits of MBME with respect to a single band multi-echo (SBME) were investigated at 3T using an event related design. : Implementation of Multi-Band in a Multi-Echo sequence shows improved sensitivity in several GM areas and benefits more from automatic non-BOLD related signal removal than a standard Multi-Echo sequence in a standard resolution, event related design at 3T.

3913.   15 Local EPI Distortion Induced by Blue Light Delivery in the Naïve Brain: Implications for Optogenetic fMRI Studies
Russell W. Chan1,2, Alex T.L. Leong1,2, Joe S. Cheng1,2, Victor B. Xie1,2, Partick P. Gao1,2, Aaron Mok2, Kevin K. Tsia2, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China

Previously, it has been reported that blue light delivery in the naïve brain resulted in pseudo positive and negative fMRI responses, which were attributed to NMR frequency shifts, and T1 and T2* changes. EPI is known to be susceptible to NMR frequency shifting, field inhomogeneity and T2* changes. However, the effects of blue light delivery in the naïve brain and EPI distortion have not been examined. The aim of this study was to investigate the local EPI distortion induced by laser stimulation in the naïve posterior thalamus. Our results showed that the pseudo negative fMRI response was at the fiber tip, while the pseudo positive fMRI response was adjacent to the pseudo negative fMRI response along the phase encoding direction. This study brings attention to EPI distortion as a possible confounder which must be taken into account when optogenetic fMRI experiments are designed.

3914.   16 Combined Echo Volumar Imaging (EVI) and Localized Excitation for Motion Insensitive Fetal fMRI
Rita G. Nunes1,2, Giulio Ferrazzi1, Anthony Price1, Matthew Fox1, Christina Malamateniou1, Mary Rutherford1, and Joseph Hajnal1,3
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Instituto de Biofisica e Engenharia Biomedica, Universidade de Lisboa, Lisbon, Portugal, 3Division of Imaging and Sciences and Biomedical Engineerin, King's College London, London, United Kingdom

Initial fMRI studies of the fetal brain have used standard multi-slice 2D EPI sequences and either required intra-volume motion correction or led to a high data rejection rate. We propose combining an EVI readout with localized excitation of the fetal brain to achieve a TR in the order of 150ms therefore significantly reducing sensitivity to motion. This methodology was shown to be feasible in three adult volunteers and a first acquisition test was performed on the fetal brain in utero.

3915.   17 Whole brain BOLD functional MRI in the presence of metallic orthodontic braces
Yuankui Wu1,2, David Woods3, Moshe T. Stern4, Nicholas I.S. Blair5, Raag D. Airan6, James J. Pekar1,7, Peter C. M. van Zijl1,7, and Jun Hua1,7
1Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States, 2Department of Medical Imaging, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China, 3Department of Orthodontics and Pediatric Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland, United States, 4Department of Orthodontics and Pediatric Dentistry, University of Maryland, Baltimore, Maryland, United States, 5Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States, 6Div. of Neuroradiology, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States, 7F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States

Gradient echo (GRE) EPI BOLD sequences are sensitive to susceptibility effects and render signal dropouts in the brain in the presence of metallic objects such as dental braces. This impedes the application of fMRI especially for studies involving teenage participants. T2prep-BOLD sequences use a readout similar to MPRAGE, which is much less sensitive to susceptibility effects. Here, we compare GRE-EPI and T2prep-BOLD in whole brain resting state fMRI scans in the presence of metallic orthodontic braces. T2prep-BOLD scans showed minimal dropout in the whole brain, and greater temporal SNR and BOLD sensitivity in the EPI dropout regions than GRE-EPI BOLD.

3916.   18 Acceleration of task-based FMRI using k-t FASTER
Mark Chiew1, Nadine N Graedel1, Stephen M Smith1, and Karla L Miller1
1FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom

We demonstrate application of k-t FASTER, a low-rank acceleration technique designed for FMRI data, on visual task FMRI data acquisition. Here, we used a 3D hybrid radial-Cartesian sampling strategy with combined parallel imaging to acquire 2 mm isotropic whole brain BOLD-weighted images at 0.6 s temporal resolution. Our results show that k-t FASTER at high accelerations is capable of capturing task-related FMRI activation with high sensitivity, and that an independent components analysis of the principal component subspace directly estimated by k-t FASTER reproduces the expected temporal and spatial patterns elicited by the visual task with high fidelity.

3917.   19 Demonstration of recovery of signal loss at 7T in Gradient Echo EPI using Tailored-RF pulses
Catarina Rua1, Stephen James Wastling2, Mauro Costagli3, Laura Biagi4, Mark Roger Symms5, Alberto del Guerra1, Mirco Cosottini1,3, Michela Tosetti3,4, and Gareth John Barker2
1University of Pisa, Pisa, Italy, 2Neuroimaging, King's College London, London, United Kingdom, 3IMAGO7 Foundation, Pisa, Italy, 4IRCCS Stella Maris, Pisa, Italy,5GE Healthcare, Pisa, Italy

We show that signal losses associated with slice selective excitation in Gradient Echo (GE) EPI at 7T can be recovered by the use of specially designed Tailored-RF (TRF) pulses. Three subjects were tested with both a standard GE sequence and a TRF modified GE-EPI pulse sequence at three different resolutions. Also, a spin-echo EPI was taken in one of the subjects for comparison. It was possible to observe signal recovery in lower temporal lobe regions in the TRF sequence even with an expected global SNR drop. This work shows a potential applicability for functional brain imaging in lower brain regions.

3918.   20 MR inverse imaging at 7T has higher spatial resolution than at 3T
Ying-Hua Chu1, Alexandre Vignaud2, Ruo-Ning Sun1, Christophe Pallier3, Wen-Jui Kuo4, Denis Le Bihan2, and Fa-Hsuan Lin1
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2CEA\DSV\I2BM\Neurospin\UNIRS, Gif sur Yvette, France,3CEA\DSV\I2BM\Neurospin\UNICOG, Gif sur Yvette, France, 4Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan

The spatial resolution of MR inverse imaging (InI) was empirically tested at 3T and 7T. By using a coil array of the same number of channel and a similar geometry at a higher field, we found that the coil sensitivity becomes more disparate and improves the condition of the spatial encoding. Compared to results at 3T, the InI spatial resolution quantified by the average point-spread function at 7T improved by about 65% and 90% at SNR = 0.1 and 1, respectively.

3919.   21 Fast functional MRI using inverse imaging with dynamic off-resonance artifacts correction
Ruo-Ning Sun1, Yi-Cheng Hsu1, Ying-Hua Chu1, Shang-Yueh Tsai2, Wen-Jui Kuo3, and Fa-Hsuan Lin1
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Institute of Applied Physic, National Chengchi University, Taipei, Taiwan,3Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan

We use the “dynamic off-resonance in k-space” (DORK) method to correct the phase drift in magnetic resonance inverse imaging (InI), Empirical results show that DORK can reduce the InI fluctuation in the respiratory frequencies, improve the stability of the fMRI time series, and increase the peak value of hemodynamic response estimates.

3920.   22 PEAK-EPI: Feasibility and benefits of k-t-undersampled EPI acquisition and PEAK-GRAPPA reconstruction in fMRI
Rebecca Ramb1, Pierre Levan1, and Jürgen Hennig1
1Department of Radiology, Medical Physics, University Medical Center, Freiburg, Germany

PEAK-EPI, i.e. permuted interleaved EPI acquisition together with PEAK-GRAPPA reconstruction, facilitates high spatial resolution (2mm at 3T) with whole brain coverage (60-63 slices) in task-related fMRI while maintaining high SNR and tSNR. Due to the shortening of the acquisition times per slice, distortion effects are mitigated. The feasibility PEAK-GRAPPA in task-related fMRI is presented with two different acquisition and reconstruction schemes and magnitude images as well as activation maps are compared to a reference EPI acquisition.

3921.   23 A Quantitative Analysis of fMRI Induced Phase Changes Using Averaged-BOSS (A-BOSS)
Mahdi Khajehim1, Abbas Nasiraei Moghaddam1,2, Gholam-Ali Hossein-Zadeh2,3, Thomas Martin4, and Danny JJ Wang4
1BME, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Tehran, Iran, 2School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran, 3ECE, University of Tehran, Tehran, Tehran, Iran, 4Neurology, UCLA, Los Angeles, CA, United States

Generally magnitude data is used in BOLD fMRI for detecting activation. By using a recently introduced steady state fMRI sequence called A-BOSS, phase changes can be reliably detected and quantified. A-BOSS has several advantages over BOSS: Its spatial coverage is not limited and the contribution of phase is not dependent on the center frequency position. Our preliminary data showed that 1) a considerable number of voxels showed phase activation (42% of total activated voxels) which could not be detected just based on magnitude data; 2) on average 0.07 radian phase change due to task activation which is consistent with Bloch equation simulation.

3922.   24 Method for epileptogenic focus localization using BOLD signal complexity analysis
Vânia Tavares1, André Santos Ribeiro1,2, Carlos Capela3, Luís Cerqueira4, and Hugo Alexandre Ferreira1
1Institute of Biophysics and Biomedical Engineering, Faculy of Sciences of the University of Lisbon, Lisboa, Portugal, 2Centre for Neuropsychopharmacology, Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom, 3Department of Neurology, Centro Hospitalar Lisboa Central, Lisbon, Portugal, 4Department of Neuroradiology, Centro Hospitalar Lisboa Central, Lisbon, Portugal

A method for localizing the epileptogenic focus from functional magnetic resonance imaging data was developed. For that purpose a bi-dimensional temporal clustering analysis was used to identify potential epileptogenic foci. Then, the complexity of the corresponding BOLD signals was analyzed to identify the most probable focus. Complexity analysis comprised the use of a modified multiscale entropy analysis algorithm and the detrended fluctuation analysis algorithm. Results showed that this method is able to localize epileptogenic tissue in agreement with clinical knowledge. Results also showed that the epileptogenic foci influence the dynamics of related brain regions within epileptic networks.

3923.   25 Fuzzy General Linear Model for functional Magnetic Resonance Imaging - permission withheld
Alejandro Veloz1,2, Luis Hernandez-Garcia3, Hector Allende2, Claudio Moraga4, Rodrigo Salas1, and Steren Chabert1
1Biomedical Engineering School, Universidad de Valparaiso, Valparaiso, Chile, 2Department of Informatics, Universidad Tecnica Federico Santa Maria, Valparaiso, Chile, 3Functional Magnetic Resonance Imaging Laboratory, University of Michigan, Ann Arbor, Michigan, United States, 4European Centre for Soft-Computing, Mieres, Spain

Since the introduction of fMRI, accurate delineation of brain activity is a relevant topic. This is a difficult task, among other reasons, due to the fact that the Haemodynamic Response varies over time, and across individuals or brain regions. This work focuses on developing a tool more adequate to represent a broader range of possible shapes of the HRF, based on the framework of fuzzy variables. Promising results are obtained in both simulation and healthy volunteer data, where the activated region obtained with the fuzzy GLM completely intersects the canonical GLM, in addition to obtaining a broader activated region.

3924.   26 Sodium fMRI detects grey and white matter activations: neuronal firing or blood volume change?
Frank Riemer1,2, Bhavana S. Solanky1, Xavier Golay2, Egidio U. D'Angelo3, and Claudia A. M. Wheeler-Kingshott1
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, Institute of Neurology, University College London, London, United Kingdom,2Department of Brain Repair and Rehabilitation, Queen Square MS Centre, Institute of Neurology, University College London, London, United Kingdom, 3Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy

Sodium (23Na) fMRI is a novel approach to study brain function. Its physiological underpinning may come from the temporal increase in intracellular sodium during neuronal firing, but also from an increase in blood volume. During finger-tapping, contralateral motor, premotor and ipsilateral somatosensory, insula and cerebellum grey matter areas are activated. Interestingly, 23Na-fMRI reveals unique activations in grey matter/white matter bordering regions where we expect the highest presence of sodium channels and in areas of associative white matter fibers such as the superior longitudinal fasciculus and the inferior cerebellar peduncle, supporting the hypothesis that 23Na-fMRI is sensitive to intracellular sodium accumulation.

3925.   27 Investigating somatotopy in SI and SII with high resolution multiband fMRI at 7T
Rosa Sanchez Panchuelo1, Keren Yang1, Martin Buehrer2, Richard Bowtell1, and Susan Francis1
1University of Nottingham, Nottingham, United Kingdom, 2Gyrotools, Zurich, Switzerland

By using multiband acquisition to extend slice coverage, we investigate body somatotopy in SI and SII with high spatial resolution at 7T. fMRI was performed during both fingertip and face-hand-foot mapping paradigms in three subjects. The fingertip mapping paradigm revealed clear digit somatotopic representation within SI, but not in SII for all subjects, suggesting an overlapping representations of the fingers in SII. The face-hand-foot mapping showed a somatotopic arrangement in SII, with the representation of the face, hand and foot ordered from lateral to medial, in agreement with previous fMRI experiments and electrophysiology in primates.

3926.   28 The neural basis for the age-related positivity effect in language processing
Sachiko Kiyama1, Mitsunobu Kunimi1, Katsuo Tamaoka2, Rinus Verdonschot3, and Toshiharu Nakai1
1National Center for Geriatrics and Gerontology, Ohbu, Aichi, Japan, 2Nagoya University, Nagoya, Aichi, Japan, 3Osaka University, Osaka, Japan

The present study aims to assess the age-related neural changes particularly concerning the role memory plays during emotional sentence processing, by employing functional magnetic resonance imaging (fMRI). Although emotional valence did not explicitly moderate behavior within sentence recognition task both in young and elderly groups, neural activity during the task showed particular interaction effects between emotional valence and age group.@ Among the enhanced regions for recognizing positive emotional sentences, the insula is known to be involved in emotional awareness. Our results suggest that the insula might reflect the elderliesf greater awareness to positive emotional sentences.

3927.   29 Investigating digit representation and tactile attention in SI/SII with a novel paradigm
Rosa Sanchez Panchuelo1, Keren Yang1, Martin Buehrer2, Miles Humberstone3, and Susan Francis1
1University of Nottingham, Nottingham, United Kingdom, 2Gyrotools, Zurich, Switzerland, 3Nottingham University Hospitals Trust, Nottingham, United Kingdom

We investigate digit representation and tactile attention in SI and SII with high spatial resolution at 7T. fMRI was performed during a novel task to modulate spatial attention between digits 2, 3 and 4 during stimulation of the digits of the left hand, each with a different periodicity. This novel paradigm revealed a clear digit somatotopy within SI, but no modulation to attention. In contrast, no somatotopic map was seen in SII, with digit responses largely overlapping, whilst SII and other cortical areas, such as SMA and pre-SMA, were strongly modulated by tactile attention in an overlapping manner.

3928.   30 Improved detection of olfactory fMRI BOLD signal with through-plane phase precompensated spectral-spatial pulses
Christopher Thomas Sica1, Prasanna Karunanayaka1, Jeff Vesek2, Jianli Wang1, and Qing X Yang1,3
1Radiology, Penn State College of Medicine, Hershey, PA, United States, 2Molecular Biology, Penn State College of Medicine, Hershey, PA, United States,3Neurosurgery, Penn State College of Medicine, Hershey, PA, United States

Susceptibility field gradients (SFG) cause undesired through-plane dephasing and associated signal loss near the sinus region, especially for fMRI scans with substantial echo times. One recently developed approach to mitigating the signal loss is the use of spectral-spatial pulses that apply a frequency dependent through-plane phase precompensation. This pre-phasing of the magnetization will cancel out the dephasing due to SFG’s, leading to signal recovery at TE. We evaluated and demonstrated the ability of spectral-spatial pulses to improve detection of BOLD activation in the olfactory regions near the base of the brain.

3929.   31 A simple approach to reducing session-dependent behavioural effects in multi-session fMRI studies
Nicholas G Dowell1 and Eleanor Denny1
1Brighton and Sussex Medical School, Falmer, Brighton, United Kingdom

In this study, we establish a sham MRI session that replicates the primary conditions of a genuine MRI scan, but without the need of a costly MRI simulator. We demonstrate that such a session can reduce the fMRI session effects that are currently observed with multi-session fMRI studies and will improve the power of these studies, increasing the likelihood of identifying subtle differences between groups. Currently, the only solution is to increase the sample size, although the costs increase as the square of the standard deviation of the unwanted effects. We introduce a more cost-effective and academically-sound approach to measure, understand and then reduce unwanted sources of variation.

3930.   32 Overlapping functional networks subserving single-digit multiplication
Joe S. Cheng1,2, Iris Y. Zhou1,2, Mengye Lyu1,2, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China

Modern neuroimaging techniques, especially fMRI, have advanced our understanding of the neuroanatomical basis of cognitive processes such as mental arithmetic. Most studies so far only attempted to relate individual activated regions with specific processes. However, the neural activation within a given region may reflect the summation of multiple distinct networks that carry different functional purposes. By combining general linear model (GLM) and independent components analysis (ICA) into contributive source analysis (CSA), this study aimed to test the hypothesis that multiple functional networks engage in simple mental task of single-digit multiplication and contribute collectively to the activations in prefrontal and parietal cortices.

Tuesday 2 June 2015
Exhibition Hall 16:00 - 17:00

  Computer #  
3931.   24 Change of Venous Susceptibility upon Visual Activation: 3D Multi-echo GRE vs. GRE-EPI Functional QSM
PINAR SENAY ÖZBAY1,2, Cristina Rossi1, Geoffrey Warnock3, Felix Kuhn3, Klaas Paul Prüssmann2, and Daniel Nanz1
1Department of Radiology, University Hospital Zürich, Zürich, Switzerland, 2Institute of Biomedical Engineering, ETH Zürich, Zürich, Switzerland, 3Department of Nuclear Medicine, University Hospital Zürich, Zürich, Switzerland

This study compared BOLD- and QSM-based neuronal activation patterns and changes of venous magnetic susceptibility under visual-stimulation as observed in data acquired with (i) traditional repeated fast whole-brain covering 2D GRE-EPI scans versus with (ii) single 3D-GRE scans. T-score-maps from statistical parametric mapping of the EPI-acquired fQSM time-series-data and difference maps (ON-OFF) for both EPI-fQSM and 3D-GRE-fQSM are presented. Image quality of 3D-GRE-fQSM and its difference-map were superior to corresponding EPI-QSM data. 3D-GRE-fQSM detected larger reduction of venous magnetic susceptibility upon visual stimulation than EPI-fQSM. 3D-GRE-fQSM might have a potential for studies with a focus on the venous vessel tree.

3932.   25 Independent Component Analysis (ICA) of functional QSM
PINAR SENAY ÖZBAY1,2, Cristina Rossi1, Geoffrey Warnock3, Felix Kuhn3, Burak Akin4, Klaas Paul Prüssmann2, and Daniel Nanz1
1Department of Radiology, University Hospital Zürich, Zürich, Switzerland, 2Institute of Biomedical Engineering, ETH Zürich, Zürich, Switzerland, 3Department of Nuclear Medicine, University Hospital Zürich, Zürich, Switzerland, 4Medical Physics, University Medical Center, Freiburg, Germany

ICA has been widely used in task-based-fMRI in order to separate independent signal components, without supplying à-priori knowledge of the paradigm. The aim of this work was to identify and characterize signal components that capture neuronal activation in quantitative susceptibility data (QSM) acquired under visual-stimulation. The effect of temporal-filtering on activation maps, signal time-course and corresponding power-spectra were investigated and results compared with those from traditional BOLD analysis. There was a strong correlation between BOLD and filtered QSM data. ICA of QSM data seems promising for an accurate localization of neuronal activation and a better understanding of the underlying mechanisms.

3933.   
26 Impaired cerebrovascular in obese children with obstructive sleep apnea compared to healthy controls
Junseok Kim1,2, Jackie Leung2, Indra Narang2, Paula Louise Croal2, and Andrea Kassner1,2
1University of Toronto, Toronto, ON, Canada, 2Hospital for Sick Children, Toronto, ON, Canada

Obesity is the most common cause of obstructive sleep apnea (OSA) in children. With childhood obesity at epidemic levels, the incidence of OSA is rising. OSA is characterized by intermittent episodes of nocturnal hypoxia, hypercapnia and sleep disruption. Moreover, intermittent hypoxia leads to oxidative damage of the endothelial cells, resulting in endothelial dysfunction which compromises vasodilatory capacity. Reduction in vasodilatory capacity can be quantified experimentally using MR-based cerebrovascular reactivity (CVR). We found that obese children with OSA have reduced CVR, both globally and regionally, compared to controls with no OSA.

3934.   27 Stability of tissue model parameters: Using the full analytical solution or the asymptotic approximation?
Sebastian Domsch1, Sebastian Weingärtner1, Jascha Zapp1, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Baden-Württemberg, Germany

The oxygen extraction fraction is of great clinical interest providing a biomarker for brain tissue viability and a parameter for the evaluation of diseases such as tumor, stroke, and Alzheimer’s disease. The analytical tissue model in the static dephasing regime has facilitated promising in-vivo results mapping hemodynamic parameters such as the OEF and the venous blood volume fraction separately using MRI. This work shows a comparison between the fit results using the full analytical model and the more frequently used asymptotic approximation in terms of accuracy and precision based on Monte-Carlo simulations and robustness in-vivo.

3935.   28 Separating the magnitude and temporal responses in a BOLD-based CO2 hypercapnia leads to improved inter-session reliability as well as characterization of hemodynamic impairment: a clinical multi-cohort study
David E Crane1, Anoop Ganda1, David J Mikulis2, Sandra E Black1, and Bradley J MacIntosh1
1Sunnybrook Research Institute, Toronto, ON, Canada, 2Toronto Western Hospital, Toronto, ON, Canada

Hypercapnia-induced cerebrovascular reactivity is a powerful tool to study the ability of the brain’s blood vessels to vasodilate. The clinical utility of CVR has been demonstrated in multiple applications. There are however continued efforts to improve the CVR time-series analysis. In this study we introduce a deconvolution approach that produces a vascular transfer function, which can be calculated by tissue type or at a voxel-wise level. We found this approach had higher sensitivity to patient group differences in white matter, compared to conventional CVR, and therefore may be useful as an adjunct approach.

3936.   29 Regional and state-dependent properties of M for high-field calibrated fMRI in rat brain
Christina Y. Shu1, Daniel Coman2, Basavaraju G. Sanganahalli2, Helen Wang2, Christoph Juchem2, Peter Herman2, and Fahmeed Hyder1,2
1Biomedical Engineering, Yale University, New Haven, CT, United States, 2Diagnostic Radiology, Yale University, CT, United States

In calibrated fMRI the BOLD signal range from deoxyhemoglobin to oxyhemoglobin is reflected by M. Since blood oxygenation changes are captured with relaxation rates by gradient echo (R2*) and spin echo (R2), M is echo time multiplied by R2’ (i.e., R2*- R2). Because it is unclear if the M range reported in calibrated fMRI studies is due to regional/state differences, we tested M estimated from R2’ in rat brain. Homogenous M values were found in the cortex regardless of the brain state. These results suggest that a direct R2’ mapping method may provide more accurate M values for calibrated fMRI.

3937.   30 Quantitative lower case Greek beta mapping for high-field calibrated fMRI in rat brain
Christina Y. Shu1, Douglas Rothman1,2, Basavaraju G. Sanganahalli2, Daniel Coman2, Peter Herman2, and Fahmeed Hyder1,2
1Biomedical Engineering, Yale University, New Haven, CT, United States, 2Diagnostic Radiology, Yale University, New Haven, CT, United States

In calibrated fMRI the power-law relationship between the BOLD signal with blood flow and oxygen consumption is quantified by the parameter β. The frequently used β value of 1.5 comes from simulation results. To make calibrated fMRI independent of assumptions and hence applicable for clinical settings, we developed a method for β mapping by measuring R2’, the most sensitive relaxation component of BOLD signal, as a function of intravascular susceptibility weighting. Since we measured lower β values in cortex than previously assumed and observed β heterogeneities across other regions, there is need for reevaluation of physiological parameters for calibrated fMRI.

3938.   31 Imaging Cerebrovascular Reserve using Combined ASL Blood Flow and BOLD: A Study using Acetazolamide Challenge in Patients with Chronic Stenosis of Major Arteries
Deqiang Qiu1, Junjie Wu1, Fadi Nahab2, and Seena Dehkharghani1
1Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States, 2Neurology, Emory University, GA, United States

In this paper, we propose to image cerebrovascular reserve (CVR) by combining repeated CBF measurements using arterial spin labeling (ASL) and BOLD. Complementary information can be provided by using both ASL and BOLD, and this is demonstrated in patients with cerebrovascular diseases.

3939.   32 Oxygen Saturation Changes During Hyperoxic and Hypercapnic Stimuli Measured by Near Infrared Spectroscopy (NIRS) Cerebral Oximetry
Hannah Hare1 and Daniel Bulte1
1FMRIB, University of Oxford, Oxford, Oxfordshire, United Kingdom

A dual-gas hypercapnia/hyperoxia paradigm as used in quantitative physiological MRI was performed while subjects were monitored with a NIRS cerebral oximeter, a finger-clip pulseox, and respiratory gas analyser to obtain arterial and tissue oxygen saturation levels. Increases in arterial and venous saturations were found by combining the group data that could not be measured in individuals. This has implications for the use of the Davis model in calibrated fMRI.

3940.   33 High Resolution Cerebral Metabolic Rate of Oxygen (CMRO2) using Quantitative Susceptibility Mapping (QSM) and an Oxygen Extraction Fraction (OEF) Constraint
Jingwei Zhang1,2, Thanh D. Nguyen2, Pascal Spincemaille2, Tian Liu3, Dong Zhou2, Ajay Gupta2, and Yi Wang1,2
1Biomedical Engineering, Cornell University, New York, New York, United States, 2Radiology, Weill Cornell Medical College, New York, New York, United States,3Medimagemetric, LLC, New York, United States

Quantitative susceptibility mapping (QSM) is advantageous over R2* for determining deoxyhemoglobin concentration from gradient echo MRI data. QSM can be used for quantitative CMRO2 mapping using pre- and post- caffeine challenge, a procedure much simpler than that required by R2*. In general, CMRO2 is sensitive to the poor SNR inherent in MRI based deoxyhemoglobin measurements. One of the noise consequence is to cause the estimated OEF exceed its physiological range. To overcome this limitation, we propose to solve for CMRO2 by constraining OEF within its physiological limit.

3941.   34 Towards high-quality simultaneous EEG-fMRI acquisitions at 7 Tesla: detection and reduction of EEG artifacts due to head motion in B0
João Jorge1,2, Frédéric Grouiller3, Wietske van der Zwaag4, Rolf Gruetter1, and Patrícia Figueiredo2
1Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Department of Bioengineering, Instituto Superior Técnico, Lisbon, Portugal, 3Biomedical Imaging Research Center, University of Geneva, Geneva, Switzerland, 4Biomedical Imaging Research Center, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

During simultaneous EEG-fMRI, the artifacts induced on EEG recordings by the strong magnetic fields employed can largely overwhelm the signals of interest. Unlike gradient and cardiac pulse-related artifacts, contributions due to spontaneous head motion in B0 have so far received little attention, but can become considerably problematic at higher field strengths. Here, an approach is presented for detection and reduction of EEG artifacts due to head motion in B0. This approach produced important reductions in EEG noise power on EEG-fMRI recordings at 7T, and largely improved sensitivity to visual responses at both a trial-average and a single-trial level.

3942.   35 Resting-state alterations in EEG-fMRI coupling in adults with attention-deficit/hyperactivity disorder
Lars Michels1,2, Steffen Bollmann2, Diego Manuel Baur2, Anthony Schläpfer3, Maya Schneebeli3, Carmen Ghisleni2, Peter Klaver2,4, Daniel Brandeis3,5, and Ruth O'Gorman2
1Institute of Neuroradiology, University Hospital Zurich, Zurich, Zurich, Switzerland, 2Center for MR-Research, University Children’s Hospital, Zurich, Zurich, Switzerland, 3Department of Child and Adolescent Psychiatry University of Zürich, University of Zurich, Zurich, Switzerland, 4Institute of Psychology, University of Zurich, Zurich, Switzerland, 5Department of Child & Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health Ma, Medical Faculty Mannheim / Heidelberg University, Mannheim, Mannheim, Germany

Attention-deficit/hyperactivity disorder (ADHD) has a high prevalence but the neurobiological mechanisms underlying ADHD remain unclear. We characterize resting EEG-fMRI coupling differences between ADHD and controls by EEG-fMRI. Based on the literature, we expected EEG-fMRI alterations in central resting and cognitive control networks. In 33 adults (17 ADHD), frequency-band specific EEG power was correlated with fMRI signal alterations during alternating eyes open and closed blocks (p < 0.05 corrected). We found bidirectional group differences in low (theta) to high (alpha) frequency bands in regions of the described networks. We conclude that sensory- and cognitive processing is compromised in adults with ADHD.

3943.   36 Removing the gradient artefact caused by 3D EPI in simultaneous EEG-fMRI experiments using a gradient model fit.
Muhammad E H Chowdhury1, Karen J Mullinger1,2, Glyn S Spencer1, and Richard Bowtell1
1SPMIC, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 2BUIC, School of Psychology, University of Birmingham, Birmingham, United Kingdom

EEG data recorded during fMRI are compromised by large gradient artefact (GA) voltages. The GA is usually corrected using average artefact correction; requiring the amplifier to have a large enough dynamic range to characterise the artefact voltages. Here we re-designed the EEG cap-cable configuration so that the GA induced in the 1 m ribbon cable by an AP gradient partially cancels that induced in the EEG cap and head. We demonstrate that the range and amplitude of the GA can be significantly reduced by cap-cable re-wiring, allowing recording at higher EEG bandwidths or increased achievable image resolution without saturation.

3944.   37 Do fMRI Resting State Networks have True High Frequency Electrical Correlates of Neural Dynamics?
Yun Wang1 and Gopikrishna Deshpande1,2
1AU MRI Research Center, Department of Electrical & Computer Engineering, Auburn University, Auburn, Alabama, United States, 2Department of Psychology, Auburn University, Auburn, Alabama, United States

Previous studies have showed that the envelope of EEG gamma band power is correlated with slow fMRI fluctuations in resting state networks. However, simultaneous EEG/fMRI studies have not been able to assess whether fMRI RSNs have a true neural basis in millisecond-scale fast neuronal dynamics. In order to address this issue, we acquired simultaneous EEG/fMRI data multiband EPI with TR =1000 and 200 ms and fused the modalities using parallel independent component analysis (pICA) such that native resolution of either modality is not compromised. Our results suggest high frequency electrical correlates for visual resting state network

3945.   38 Ballistocardiogram artefact correction taking into account background physiological signal preservation in simultaneous EEG-fMRI
Rodolfo Abreu1, Marco Leite1,2, Alberto Leal3, and Patrícia Figueiredo1
1Institute for Systems and Robotics and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal, 2Department of Clinical and Experimental Epilepsy and The Wellcome Trust Centre for Neuroimaging, University College London Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom, 3Centro de Investigação e Intervenção Social and Department of Neurophysiology, Centro Hospitalar Psiquiátrico de Lisboa, Lisbon, Portugal

Ballistocardiogram artefact (BCG) seriously compromises EEG data quality when simultaneously-acquired with fMRI. Here, we propose a novel ICA-based approach (PROJIC) for BCG artefact correction as well as a novel evaluation pipeline that assesses both artefact and background signal removal. The proposed evaluation pipeline for BCG artefact correction allowed different weightings of the importance of removing the artefact against preserving the signal background, showing that different methods may be preferred in different situations. The proposed ICA-based approaches outperformed both previous ICA-based methods as well as the Optimal Basis Sets (OBS) approach, in all conditions.

3946.   39 Interactively computing and visualizing functional and structural brain connectivity in real-time
Maxime Chamberland1, Michaël Bernier1, David Fortin2, Kevin Whittingstall3, and Maxime Descoteaux4
1Nuclear Medecine and Radiobiology, Université de Sherbrooke, Sherbrooke, Québec, Canada, 2Neurosurgery, Université de Sherbrooke, Sherbrooke, Québec, Canada, 3Diagnostic Radiology, Université de Sherbrooke, Sherbrooke, Québec, Canada, 4Computer science, Université de Sherbrooke, Sherbrooke, Quebec, Canada

The human brain can be viewed as a collection of networks. Those highly specialized networks can be referred to as a set of nodes (gray matter functional areas) linked together by edges (for example white matter axonal structure). In this work, we propose an interactive tool for the exploration of functional connectivity in a fully 3D fashion, which can be coupled with our existing real-time fiber tracking module.

3947.   40 Evaluation of a Cerebral-Blood-Volume (CBV) pharmaco-MRI (phMRI) Assay Utilizing Low (0.1mg/70kg) and High (0.2mg/70kg) Dose Buprenorphine Infusion and a Novel USPIO Contrast Agent (Ferumoxytol) in Healthy Human Subjects.
Richard Baumgartner1, Arie Struyk2, Jeff Evelhoch2, Cynthia Gargano2, Francheska Colon Gonzalez2, Haiying Liu1, Ruben Declercq3, Hans Verheyden3, Ingeborg Heirman3, Hans De Pla4, Griet Van Lancker4, Sofie Van den Abeele4, Adelheid Hollebosch4, Brant Delafontaine4, Luc Van Bortel4, Rik Achten4, Patricia Clement4, Pieter Vandemaele4, Dai Feng1, and Sofia Apreleva1
1Merck and Co, Rahway, New Jersey, United States, 2Merck and Co, Pennsylvania, United States, 3Merck and Co, Belgium, 4Ghent University, Belgium

We present results from a clinical trial of pharmaco-MRI (phMRI) employing cerebral blood volume (CBV) imaging using ferumoxytol (Rienso/Feraheme, AMAG) as a blood pool contrast agent. The study examined the pharmacodynamic effects of two single doses of buprenorphine (0.2mg/70kg and 0.1mg/70kg administered intravenously). We found that contrast-enhanced CBV phMRI signals are more sensitive reporters of pharmacodynamic effects than conventional blood oxygen level dependent (BOLD) phMRI. In particular, higher sensitivity of CBV phMRI compared to BOLD allows for elucidation of PD responses at lower doses of buprenorphine, which has practical implications for similar phMRI studies with centrally acting drugs.

Tuesday 2 June 2015
Exhibition Hall 17:00 - 18:00

  Computer #  
3948.   42 Aberrant Brain Resting-State Functional Connectivity in Patients with Obstructive Sleep Apnea
Bumhee Park1, Jose A Palomares1, Mary A Woo2, Daniel W Kang3, Paul M Macey2, Frisca L Yan-Go4, Ronald M Harper5, and Rajesh Kumar1,6
1Anesthesiology, University of California at Los Angeles, Los Angeles, CA, United States, 2School of Nursing, University of California at Los Angeles, Los Angeles, CA, United States, 3Medicine, University of California at Los Angeles, Los Angeles, CA, United States, 4Neurology, University of California at Los Angeles, Los Angeles, CA, United States, 5Neurobiology, University of California at Los Angeles, Los Angeles, CA, United States, 6Radiological Sciences, University of California at Los Angeles, Los Angeles, CA, United States

OSA subjects show impaired autonomic, affective, executive, sensori-motor, and cognitive functions. Brain injury, assessed by various MRI procedures, appears in multiple sites regulating these functions; however, the integrity of functional networks remains unclear. We examined resting functional interactions and complex network organization across the whole-brain in OSA over controls and found aberrant functional connections and altered brain network organization in those regions. The findings suggest that impaired functions in OSA may stem from altered functional connectivity and brain network organization. The outcomes likely result from prominent structural brain changes in both axons and nuclear structures reported-earlier.

3949.   43 Development of the relationship between the Default Mode Network and frontal task-positive areas in preterm newborns: a RS-fMRI study.
Elisa Marchetta1,2, Sara Cirillo1, Pasquale Della Rosa3, Silvia Pontesilli1, Andrea Falini1,4, Graziano Barera5, Cristina Baldoli1,4, and Paola Scifo6,7
1Neuroradiology Dept., San Raffaele Hospital, Milan, -, Italy, 2University of Milano-Bicocca, Milan, -, Italy, 3Institute of Molecular Bioimaging and Physiology, CNR, Segrate, -, Italy, 4Vita-Salute San Raffaele University, Milan, -, Italy, 5Division of Neonatology, Pediatrics Dept, San Raffaele Hospital, Milan, -, Italy, 6Nuclear Medicine Dept., San Raffaele Hospital, Milan, -, Italy, 7CERMAC, San Raffaele Hospital, Milan, -, Italy

The brain functional architecture grows fast during prenatal period. This study aims to investigate the development of DMN and its correlation with frontal task-positive areas by means of Resting State fMRI in a group of healthy preterm newborns. Interestingly, we found significant correlations between mPFC and the frontopolar region. This functional association was also found to be significantly correlated with age. Our results suggest that the recruitment of regions involved in high order functions might start since the very early age, although frontal areas are characterized by late myelination and expected late connectivity.

3950.   44 Functional connectivity changes of Dentate Nucleus in Autism Spectrum Disorders: a resting-state fMRI study.
Giusy Olivito1,2, Maria Leggio1,2, Fiorenzo Laghi3, Roberto Baiocco3, Anna Maria Tedesco1, Silvia Clausi1, Chiara Mastropasqua4, Marco Molinari5, Mara Cercignani4,6, and Marco Bozzali4
1Ataxia Research Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, Italy, 2Department of Psychology, Faculty of Medicine and Psychology, University of Rome "Sapienza", Rome, Italy, Italy, 3Department of Developmental and Social Psychology, Faculty of Medicine and Psychology, University of Rome "Sapienza", Rome, Italy, Italy, 4Neuroimaging Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, Italy, 5Neurological and Spinal Cord Injury Rehabilitation, Department  A, IRCCS Santa Lucia Foundation, Rome, Italy, Italy, 6Clinical Imaging Science Center (CISC), Brighton and Sussex Medical School, Brighton, Sussex, United Kingdom

The cerebellum has emerged as one of the regions affected in Autism spectrum disorders (ASDs). The cerebro-cerebellar disconnection could in part underlie autistic symptoms, mainly involving “Theory of Mind” (ToM) processes. In the present study we demonstrate the usefulness of resting-state fMRI in detecting changes in functional connectivity (FC) between the cerebellar dentate nucleus, the sole cerebellar output channel, and cerebral cortex regions by comparing ASD patients and tipically developing subjects. Using a seed-based approach, we found altered FC in ASDs patients between DN and regions of the Default Mode Network, known to be related to social deficits seen in ASD.

3951.   45 The impact of white matter hyperintensities on brain functional connectivity in amnestic mild cognitive impairment patients.
Mario Torso1, Chiara Mastropasqua1, Giovanni Giulietti1, Laura Serra1, Giusy Olivito2,3, Elisa Tuzzi1, Barbara Spanò1, Carlo Caltagirone4,5, Mara Cercignani6, and Marco Bozzali1
1Neuroimaging Laboratory, Santa Lucia Foundation, IRCCS, Rome, Italy, 2Ataxia research Laboratory, Santa Lucia Foundation, IRCCS, Rome, Italy, 3Department of psychology, University of Rome Sapienza, Rome, Italy, 4Department of Clinical and Behavioural Neurology, Santa Lucia Foundation, IRCCS, Rome, Italy,5Department of Neuroscience, University of Rome ‘Tor Vergata’, Rome, Italy, 6CISC, Brighton & Sussex Medical School, Brighton, Sussex, United Kingdom

In this study we used resting state f-MRI to investigate the contribution of White Matter Hyperintensities (WMHs) in determining functional connectivity (FC) changes in amnestic Mild Cognitive Impairment patients, the prodromal stage of Alzheimer disease. WMHs volumes were quantified by semiautomatic method on TSE images and used to distinguish patients in two different groups (high WMHs volume –H and low WMHs volume –L). The main finding of the study was that a higher WMHs volume can determine changes in FC and that these alterations are associated with the presence of cognitive deficits in the patients.

3952.   46 Observing the activity change of the baseline brain in Benign Essential Blepharospasm with fractional amplitude of low-frequency fluctuation - permission withheld
Mingfei Ni1, Weiwei Wang1, Ziheng Zhang2, Qingwei Song1, Ailian Liu1, and Yanwei Miao1
1Radiology Department, the First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China, 2GE Healthcare China, Beijing, China

Objective:To investigate the activity changes of the baseline brain in patients with Benign Essential Blepharospasm (BEB) by resting-state fMRI fractional amplitude of low-frequency fluctuation (fALFF) method.Methods:28 patients with BEB and 28 healthy controls group were scanned on a 3.0T MRIscanner. The image data were analyzed with software SPM8, DPARSF and REST. Results The whole brain analysis indicated that in comparison with the normal control group, there was a ncreased fALFF in the right major sensorimotor area£¬right caudate head£¬left thalamus. the fALFF in the left thalamus were positively correlated with the JRS total score.

3953.   47 Altered resting state functional connectivity in hypothyroidism
Subash Khushu1, Sadhana Singh1, Mukesh Kumar1, Shilpi Modi1, Prabhjot Kaur1, and L Ravi Shankar2
1NMR Research Centre, INMAS, DRDO, Delhi, Delhi, India, 2Thyroid Research Centre, INMAS, DRDO, Delhi, Delhi, India

Hypothyroidism affects brain functioning as suggested by various neuroimaging studies. The primary focus of this study was to examine whether hypothyroidism would impact connectivity among resting state networks with the use of resting-state fMRI. Our results showed significantly decreased functional connectivity in the region of right fronto-parietal network, medial visual network and motor network in hypothyroid patients as compared with healthy controls. These findings suggest dysfunction of motor and cognitive functions in hypothyroidism.

3954.   48 Functional connectivity MRI can distinguish experimental pain from the resting state with seed ROI in the posterior insula, but not the anterior insula
Keith M Vogt1 and James W Ibinson2
1Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, United States, 2Center for Pain Research, Dept of Anesthesiology, University of Pittsburgh, Pittsburgh, PA, United States

The portion of the insula chosen as the seed region for functional connectivity MRI (fcMRI) analysis can dramatically affect the resulting maps. This is particularly important when comparing maps obtained during rest to those during experimental pain. In this fcMRI study, seed region analyses revealed that the difference maps for posterior insula Pain vs Rest connectivity was obviously different than those seen with an anterior insular seed region. Thus, the posterior insula is a putative brain area for differentiating the experience of acute pain from rest, while the anterior insula does not exhibit this specificity.

3955.   49 Resting-state functional network abnormalities in major depressive disorder with self-harm: a connectome analysis
Zhen-Hui Li1,2, Vincent Chin-Hung Chen3, Ming-Chou Ho4, and Jun-Cheng Weng1,2
1Department of Biomedical Sciences, Chung Shan Medical University Hospital, Taichung, Taiwan, 2School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 3Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan, 4Department of Psychology, Chung Shan Medical University, Taichung, Taiwan

Major depressive disorder (MDD) is a public health problem in recent years. MDD is characterized by emotional imbalance with extremely in emotional processing. MDD patient with self-harm may eventually result in the death. Previous studies showed abnormal functional connectivity between specific brain regions, and few studies demonstrated the functional network can be observed by the large-scale structural pathways interconnecting. Graph theory is capable of evaluating the topological organization of the human brain. Therefore, in this study we tried to find out the functional connectomic difference between MDD patients and healthy subjects based on resting-state functional magnetic resonance imaging (rs-fMRI) using graph theoretical and network-based statistic (NBS) analyses. Our results revealed that MDD patients exhibit a disruption in the topological organization of functional brain networks.

3956.   50 Relationship between Visual Functional Connectivity and Duration of Blindness Depends on Onset of Visual Deprivation
Matthew C. Murphy1, Amy C. Nau1, Christopher Fisher1, Seong-Gi Kim2,3, Joel S. Schuman1,4, and Kevin C. Chan1,4
1Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States, 2Departments of Biological Sciences and Global Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, 3Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 4Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States

Visual deprivation is known to induce plasticity of the visual system, which can be observed through alterations in functional connectivity (FC). How these FC changes accrue over time and how this relationship between FC and duration of blindness differs between early and late acquired blindness are unknown. In this work, we modeled the effects of prior visual experience on visual FC in blind subjects. The results suggest that alterations in FC due to visual deprivation progress over time, however the direction of this progression in congenitally blind subjects is opposite to that in subjects with acquired blindness.

3957.   51 Dynamic changes in whole-brain functional connectivity during story listening
Gloria Castellazzi1,2, Fulvia Palesi2,3, Ahmed T. Toosy4, Stefania Bruno5, Egidio D'Angelo2,6, and Claudia A.M. Wheeler-Kingshott7
1Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, PV, Italy, 2Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, PV, Italy, 3Department of Physics, University of Pavia, Pavia, PV, Italy, 4Department of Brain Repair and Rehabilitation, Queen Square MS Centre, UCL Institute of Neurology, London, England, United Kingdom, 5Overdale Hospital, Jersey, England, United Kingdom, 6Department of Brain and Behavioral Sciences, University of Pavia, Pavia, PV, Italy, 7NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, England, United Kingdom

During complex “continuous” cognitive tasks, the brain elaborates information over multiple domains and time scales. These operations contribute to dynamically shape, over space and time, the whole-brain functional connectivity. We used rs-fMRI to investigate the changes in brain functional connectivity occurring in subjects listening to a narrated story. Results show that the listening task dynamically alters the shape of the functional connectome in a non-random way, affecting sensory prior that cognitive brain networks. A possible interpretation looks at the brain as a “prediction engine” that constantly generates predictions about the optimal configuration of the networks to process the impending input.

3958.   52 Wavelet Coherence Analysis of Functional Connectivity within Default Mode Network Employing Simultaneous MultiSlice (SMS) Resting-state fMRI - permission withheld
Hesamoddin Jahanian1, Samantha Holdsworth1, Thomas Christen1, Hua Wu2, Kangrong Zhu3, Adam Kerr3, Mathew J Middione4, Robert F Dougherty2, Michael Moseley1, and Greg Zaharchuk1
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Center for Cognitive and Neurobiological Imaging, Stanford University, Stanford, CA, United States, 3Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 4Applied Sciences Laboratory West, GE Healthcare, Menlo Park, CA, United States

In this work we studied the dynamics of functional connectivity within the default mode network using high temporal sampling rate (TR=350 ms) Simultaneous MultiSlice (SMS) Resting-state fMRI. We performed wavelet coherence analysis in two frequency bands: 0.01-0.1 Hz and above 0.1 Hz. Our results indicate that functional connectivity occurs at multiple frequency bands – including those above 0.1 Hz that are commonly ignored in rsfMRI studies – and exhibits dynamic changes within time scales of seconds to minutes.

3959.   53 Dynamic Wavelet Coherence Maps and Frequency-Dependent Connectivity Strength in Default Mode Network
Hsu-Lei Lee1, Jakob Assländer1, Pierre LeVan1, and Jürgen Hennig1
1Medical Physics, University Medical Center Freiburg, Freiburg, BW, Germany

We used wavelet analysis to demonstrate dynamic coherence maps with respect to different brain regions. A frequency-dependent connectivity behaviour of default mode network was observed, where idividual parts of the network become less synchronized as signal frequency increases.

3960.   54 Default Mode Network activity during spontaneous movement events
Francisca Marie Tan1,2, Karen Mullinger1, Yaping Zhang2, David Siu-Yeung Cho2, Susan Francis1, and Penny Gowland1
1Sir Peter Mansfield Imaging Centre, The University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Department of Electrical and Electronic Engineering, The University of Nottingham Ningbo China, Ningbo, Zhejiang, China

The Default Mode Network (DMN) is associated with anti-correlation with task positive networks. In this study, we investigate the DMN’s response to spontaneous motor events that are detected in the Somatosensory Network. Sparse paradigm free mapping is used to detect three movement types: long and short motor tasks, and spontaneous movements without prior timing information. DMN activity is compared for these three types. Results indicate that the DMN has higher average of activation for spontaneous events compared to task events. This analysis can be further extended to explore the DMN’s behaviour for spontaneous events in other networks.

3961.   55 Alterations in regional homogeneity of resting-state brain activity in patients with Chronic Prostatitis/Chronic Pelvic Pain Syndrome
Yan Bai1, Carlos Torres2, Peng Liu3, Xuejuan Yang3, Dapeng Shi1, Jie Tian4, and Meiyun Wang1
1Department of Radiology, Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China, 2Division of Neuroradiology, Department of Radiology, University of Ottawa, Ottawa, ON, Canada, 3School of Life Sciences and Technology, Xidian University, Shaanxi, China, 4Institute of Automation, Chinese Academy of Sciences, Beijing, China

The prevalence rate of Chronic prostatitis/Chronic pelvic pain syndrome (CP/CPPS) is approximate 9-16% in the world.However, the pathogenesis of CP/CPPS has been largely unknown so far. Our findings may be helpful for further study on the central mechanism of CP/CPPS.

3962.   56 Investigation of local brain activity changes in restless legs syndrome using regional homogeneity: a preliminary study
Yong Zhang1, Kang-An Li2, Yun-Cheng Wu2, Qian Jiang1, Zhenyu Zhou3, and Gui-Xiang Zhang2
1GE Healthcare China, Shanghai, Shanghai, China, 2Shanghai First People’s Hospital, Shanghai, Shanghai, China, 3GE Healthcare China, Beijing, Beijing, China

This preliminary study used regional homogeneity (ReHo), a novel resting-state fMRI parameter to investigate local brain activity changes in restless legs syndrome (RLS), a common neurological disorder characterized by an urge to move the legs and paraesthesias deep in the legs. Ten RLS patients and ten age- and gender-matched healthy controls were recruited for comparison. The RLS group showed increased ReHo regions in bilateral middle frontal gyrus, anterior cingulate cortex, caudate nucleus, insula, left putamen and thalamus as compared to normal controls, which might provide interesting insight into the mechanism of the disease.

3963.   57 An exploration of task based fMRI in neonates using echo-shifting to allow acquisition at longer TE without loss of temporal efficiency
Giulio Ferrazzi1, Rita G. Nunes1,2, Tomoki Arichi1, Maryam Abaei1, Emer Hughes1, Anthony Price1, and Joseph Hajnal1,3
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Instituto de Biofisica e Engenharia Biomedica, Universidade de Lisboa, Lisbon, Portugal, 3Division of Imaging and Sciences and Biomedical Engineering, King's College London, London, United Kingdom

There is growing interest in fMRI of neonates. However, T2* is longer in immature brains, suggesting that optimal fMRI requires different parameter settings. We explore the use of echo-shifted EPI to detect task activation in a motor paradigm in neonates using longer echo-times to enhance sensitivity to the BOLD effect, first testing for a suitable echo time and then running dual echo and echo shifted sequences on a small group of infants. The pilot data obtained confirmed that longer echo times improve detection of motor activation and that signal recovery combined with increased efficiency can be achieved with echo-shifting.

3964.   58 Analysis of functional connectivity by local bold signal variance
Gregory Kirk1, Rasmus Birn2, and Andrew Alexander3
1Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin,Madison, Madison, Wi, United States, 2Psychiatry, University of Wisconsin,Madison, Madison, Wi, United States, 3University of Wisconsin,Madison, Madison, Wisconsin, United States

We present a method of characterizing the state of functional connectivity of every vertex over the entire cerebral cortex on an individual subject level. The method is based on a discovered relation between the synchrony of bold fmri time series in a small neighborhood of a vertex and the scale of global functional connectivity of the time series at the vertex. The scale is defined by the number of vertices with epi time series correlation at or above a reference pearson linear correlation level r. The relation is demonstrated by a large scale computation of 120 resting fmri scans.

3965.   59 Functional connectivity assessment using R2* resting-state functional MRI
Venkata Veerendra Nadh Chebrolu1, Suresh Joel1, Brice Fernandez2, Ek Tsoon Tan3, Luca Marinelli3, Dattesh Shanbhag1, Radhika Madhavan1, Rachel Connett4, Ajit Shankaranarayanan4, and John Schenck5
1Medical Image Analysis Lab, GE Global Research, Bangalore, Karnataka, India, 2GE Healthcare, Muenchen, Germany, 3MRI Laboratory, GE Global Research, NY, United States, 4GE Healthcare, CA, United States, 5MRI Technologies & Systems, GE Global Research, NY, United States

In recent years, resting state functional connectivity (rs-FC) has been widely used to image brain function. rs-FC is measured by correlation of blood oxygen level dependent (BOLD) MRI signal time-courses. BOLD signal has contributions from cerebral blood flow (CBF), cerebral blood volume (CBV) and cerebral metabolic oxygen rate (CMRO2). The initial magnetization (M) is associated with CBF and CBV. Transverse relaxation rate (R2*) is associated with CMRO2, which is related more specifically with neuronal activity than CBF and CBV. In this work, we estimate functional connectivity using R2* time-courses and compare the results with conventional BOLD rs-fMRI.

3966.   60 3D Hybrid Radial-Cartesian Sampling for Improved Resting State FMRI using k-t FASTER
Mark Chiew1, Nadine N Graedel1, Jennifer A McNab2, Stephen M Smith1, and Karla L Miller1
1FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom, 2Radiology, Stanford University, California, United States

In this work, the k-t FASTER method for accelerating resting state FMRI data acquisition is demonstrated using a 3D hybrid radial-Cartesian acquisition, which facilitates accelerated reconstruction at multiple temporal resolutions. We combine k-t FASTER acceleration with parallel imaging, using radial acceleration factors ranging from R=1.67 to R=12.5x to produce 2 mm isotropic whole brain images at TRs ranging from 3 s down to 0.4 s. Resting state network expression is found to be optimised when the benefit of increased temporal degrees of freedom (provided by higher acceleration), is offset by diminishing reconstruction quality.

3967.   61 Characterization of Whole-brain Dynamic Connectivity Patterns using Simultaneous MultiSlice (SMS) Resting-State fMRI - permission withheld
Hesamoddin Jahanian1, Samantha Holdsworth1, Thomas Christen1, Hua Wu2, Kangrong Zhu3, Adam Kerr3, Matthew J Middione4, Robert F Dougherty2, Michael Moseley1, and Greg Zaharchuk1
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Center for Cognitive and Neurobiological Imaging, Stanford University, Stanford, CA, United States, 3Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 4Applied Sciences Laboratory West, GE Healthcare, Menlo Park, CA, United States

In an effort to distinguish cognitive states of the brain from rsfMRI data, we studied the dynamics of the whole-brain functional connectivity using high temporal sampling rate (TR=350 ms) Simultaneous MultiSlice (SMS) Resting-state fMRI. We probed the whole-brain functional connectivity in a wide frequency spectrum over a sliding window (duration:17.5 s, steps:7 s) and further characterized its dynamic changes into distinct connectivity states using k-means clustering.

3968.   62 Hierarchical parcellation using discrete Morse theory of whole-brain high-resolution resting-state 7T fMRI data
Afonso Dias1, Marta Bianciardi2, Sandro Nunes1, Rodolfo Abreu1, Juliana Rodrigues1, L. Miguel Silveira3, Lawrence L. Wald2, and Patricia Figueiredo1
1Institute for Systems and Robotics and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Lisbon, Portugal, 2Department of Radiology, A.A. Martinos Center for Biomedical Imaging, MGH and Harvard Medical School, Boston, MA, United States, 3INESC-ID and Department of Electrical and Computer Engineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Lisbon, Portugal

Parcellation of the brain into functionally meaningful regions is a crucial step in studies of brain connectivity using complex network analysis methods based on resting-state fMRI (rs-fMRI). With the recent development of fast acquisition sequences at ultra-high-field (7T), high-spatial-resolution rs-fMRI can now be collected from the whole-brain with sufficient temporal resolution to capture the slow haemodynamic fluctuations underlying functional brain connectivity. We present a modification based on discrete Morse theory of a previously proposed method of hierarchical brain parcellation with rs-fMRI. We show that the method is able to produce parcellations at high levels of detail, with good intra-subject reproducibility.