Electronic Posters : Functional MRI
Click on to view the abstract pdf and click on to view the video presentation.
MRI Fluctuations: Artifacts & Information

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 56

14:00 3624.   The effect of flip angle on BOLD fMRI sensitivity 
Javier Gonzalez-Castillo1, Vinai Roopchansingh2, Peter A. Bandettini1,2, and Jerzy Bodurka3
1Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States, 2Functional MRI Facility, National Institute of Mental Health, Bethesda, MD, United States, 3Laureate Institute for Brain Research, Tulsa, OK, United States

Flip angles near the Ernst angle are commonly used in fMRI to maximize image SNR. However, lower angles provide significant benefits such as better tissue contrast, less inflow effect, less through-plane motion artifacts, and reduced levels of radio-frequency energy deposition. Recent research has shown that TSNR, a better predictor of sensitivity than SNR, stays fairly constant and close to its maximum value for a wide range of angles when physiological noise dominates. Here we explore the hypothesis that low flip angles have no detrimental effects on our ability to detect BOLD neuronal activations; and might be advised for fMRI experiments

14:30 3625.   Investigating cardiac pulsatility in the brain using EPI sequences: from physiological noise to physiological information 
Ilia Makedonov1,2, David E Crane1, and Bradley J MacIntosh1,3
1Heart and Stroke Foundation Centre for Stroke Recovery, Toronto, ON, Canada, 2Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada, 3Medical Biophysics, University of Toronto, Canada

Cardiac noise is usually filtered and otherwise minimized in resting state BOLD fMRI scans. One theory posits that mechanical damage due to cardiac pulsatility is implicated in brain aging and contributes to the formation of pathological small vessel disease. The purpose of this abstract is to characterize cardiac physiological signal in BOLD fMRI and to compare young and elderly groups. Our preliminary results shows that cohort differences exist between the extent of cardiac pulsatility in gray matter in the young and elderly.

15:00 3626.   A random-walk driven segmentation of resting state fMRI data: evaluation of visual cortex sub-communities is enhanced by physiological noise correction 
Tommaso Gili1, Ibrahim Eid2, Kevin Murphy1, Ashley Harris1, Guido Caldarelli3, Bruno Maraviglia2, and Richard Geoffrey Wise1
1Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom, 2Dipartimento di Fisica, Università di Roma Sapienza, Roma, Italy, 3CNR-ISC Dipartimento di Fisica, Univeristà di Roma Sapienza, Roma, Italy

Parcellation of the cortex into individual subunits based on correlations in resting-state data opens up the possibility of developing a subunit atlas analogous to the Brodmann areas but based on cortical function rather than cytoarchitecture. Graph theory is a common methodology for studying complex networks. Graph-based clustering approaches have also been applied to the analysis of brain networks using resting-state fMRI. Here we used a random-walk-based algorithm to parcellate visual cortex in healthy subjects in a resting-state condition. Moreover we demonstrate the need for physiological noise removal to obtain consistent results across subjects from this functional segmentation method.

15:30 3627.   Relationship between spontaneous fluctuations in end-tidal PCO2 and apparent resting state functional connectivity 
Cécile Madjar1, Claudine Joëlle Gauthier1,2, Rasmus M Birn3, and Rick D Hoge1,2
1CRIUGM/UNF, Montréal, Québec, Canada, 2Physiology/Biomedical Engineering, University of Montréal, Montréal, Québec, Canada, 3University of Wisconsin, Madison, WI, United States

With the ever-increasing number of studies investigating the default-mode network (DMN), there has been a growing interest in trying to take into account the confounding effects from physiological noise, such as respiration, while performing connectivity analysis of fMRI. Variations in respiration cause fluctuations in end-tidal CO2 (ETCO2) which have been shown to exert a significant effect on BOLD fMRI signal. Here we present data comparing resting-state correlations in the DMN, as well as task-related activations, between two conditions: 1) while tightly controlling for ETCO2 concentrations, and 2) while ETCO2 values were allowed to vary spontaneously.

Tuesday May 10th
  13:30 - 15:30 Computer 56

13:30 3628.   A simple method to reduce signal fluctuations in fMRI caused by the interaction between motion and coil sensitivities 
Axel Hartwig1, Mathias Engström1, Olof Flodmark1, Martin Ingvar1, and Stefan Skare1
1Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden

In this study, we show the level of interaction between head motion and coil sensitivities for 32-channel fMRI data, in the absence of fMRI stimulus. The magnitude of the coil sensitivity induced signal fluctuations, introduced after image realignment, are similar to common BOLD-response levels, why this can affect the fMRI analysis when motion and the BOLD response are partially correlated. Our method involves a measurement of the coil sensitivity field. By simply normalizing the fMRI data - prior to realignment - with this field, the signal fluctuations - post-realignment - can be largely reduced.

14:00 3629.   Identifying and separating the RF fluctuations from the measurement noise 
Costin Tanase1, Jeffrey O'Hara2, Denise Davis3, Fernando Boada3, Michael H Buonocore4, and Cameron S Carter1
1Psychiatry and Behavioral Sciences, University of California at Davis, Sacramento, CA, United States, 2Siemens Medical Solutions, 3University of Pittsburgh, United States,4Radiology, University of California Davis, United States

It is well accepted that the statistical assessment of fMRI data can be improved by estimating the measurement noise as well as the fMRI series fluctuations due to slow physiological processes. While recent fMRI literature has characterized a larger array of increasingly subtler physiological fluctuations, there is still an overriding assumption that the “leftover” variance in the data can be described by “stationary Gaussian noise”. By analyzing the QA data, the extracted temporal series demonstrate the presence of signal fluctuations that are non-random and consistent across multiple runs.

14:30 3630.   Modelling temporal stability of EPI time series acquired with multi-channel receiver coils: treatment of noise correlation 
Chloe Hutton1, Antoine Lutti1, and Nikolaus Weiskopf1
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, United Kingdom

Temporal signal-to-noise ratio (SNR) has been characterized as a function of image SNR for fMRI time series allowing physiological noise to be separated from thermal noise. This model is only valid for data acquired with a single-channel receiver coil. Here we propose an extension of this model to allow for state-of-the-art multi-channel acquisition mode, commonly used for fMRI studies. Using Monte Carlo simulations and 7T task-free fMRI, we show improved fit of the extended model for data where noise correlations are present. This extended model allows for characterization of temporal SNR and physiological noise using data acquired with multi-channel receiver coils.

15:00 3631.   Reducing a Localized Signal Fluctuation Artifact in fMRI using Spectral-Spatial Fat Saturation 
Dan Xu1, Jian Zhang2, Richard Scott Hinks1, and Kevin F. King1
1Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States, 2Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States

Conventional 1D, spatially non-selective fat saturation can generate uncrushed fat signals in areas where crusher is weak because of reduced gradient linearity. These fat signals can corrupt in-plane water signal, and in fMRI, they manifest themselves as artifacts such as clouds in image background or localized signal fluctuation over time. We propose a spectral-spatial fat saturation method to remove these artifacts while preserving thin slice capability, pulse duration, and fat suppression performance.

Wednesday May 11th
  13:30 - 15:30 Computer 56

13:30 3632.   Utility of T2-Weighted Anatomical Images for fMRI Physiological Noise Visualization 
Raquel Phillips1, Vadim Zotev1, Jonathan Savitz1, Ruben Alvarez1, W Kyle Simmons1, Patrick Bellgowan1, Wayne Drevets1, and Jerzy Bodurka1
1Laureate Institute for Brain Research, Tulsa, OK, United States

Physiological noise is a major confounding factor in BOLD fMRI. We will show the utility of T2-weighted anatomical fast-spin-echo images for fMRI physiological noise visualization. We propose a method for processing T1- and T2-weighted anatomical high-resolution images that highlights brain compartmentalization at lower fMRI resolution. Such images are formed by computing spatial standard deviation (SDs) from neighboring voxel intensities within the anatomical volume. Because of the large signal difference with fast-spin-echo between cerebrospinal fluid, grey matter, and/or vasculature, the T2-based SDs image predicts well the brain areas where the fMRI signal temporal variation will be present.

14:00 3633.   Prediction and correction of physiological noise in fMRI using machine learning 
Tom Ash1, John Suckling2, Martin Walter3, Cinly Ooi2, Claus Tempelmann4, Adrian Carpenter1, and Guy Williams1
1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 2Brain Mapping Unit, University of Cambridge, Cambridge, United Kingdom,3Department of Psychiatry, University of Magdeburg, Magdeburg, Germany, 4Department of Neurology, Otto v. Guericke University, Magdeburg, Germany

We present a support vector machine based technique for recreation of partially or fully absent physiological recording data, to allow detrending of physiological noise to occur even in the absence of complete recordings of the physiological cycles. The technique uses a multi-class SVM to predict phase of each physiological cycle from fMRI image data, after training on prior data. Using these predicted phase values as inputs to physiological detrending tool RETROICOR show similar impact on Fourier transforms of the data as using recorded values, showing that they are accurate enough for use as inputs to detrending tools.

14:30 3634.   Increased SNR and activation in Hadamard-encoded fMRI through physiological noise removal and phase correction 
Alan Chu1,2, Jon-Fredrik Nielsen1, Scott J. Peltier1, and Douglas C. Noll1
1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States, 2University of Michigan Medical School, Ann Arbor, MI, United States

Hadamard-encoded fMRI is a multislice acquisition method that increases SNR. Because the method uses temporal filtering on complex data for subslice extraction, the method is more susceptible to physiological noise and phase fluctuations when compared with conventional fMRI, where only the magnitude is typically used for determination of voxel activation. In this work, we introduce both physiological noise removal and phase correction for Hadamard-encoded fMRI, and compare the resulting functional activation with that of a conventional fMRI scan.

15:00 3635.   Optimized physiological noise correction for 3D EPI time series 
Antoine Lutti1, Oliver Josephs1, Dave Thomas2, Rebecca Lawson3, Jonathan P Roiser3, Chloe Hutton1, and Nikolaus Weiskopf1
1Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom, 2Institute of Neurology, Department of Brain Repair and Rehabilitation, University College London, London, United Kingdom, 3Institute of Cognitive Neuroscience, University College London, London, United Kingdom

The use of 3D EPI for the study of brain activity has been limited due to its high sensitivity to physiological noise which counteracts its higher image SNR compared to 2D EPI. In this work, we present an optimized method for physiological noise correction of 3D EPI. The impact of the correction is stronger than for 2D EPI, showing that the higher susceptibility of 3D EPI to physiological noise can be overcome, leading to significantly higher tSNR values.

Thursday May 12th
  13:30 - 15:30 Computer 56

13:30 3636.   Physiological origin of systemic artifacts in functional near infrared spectroscopy as revealed by fMRI 
Evgeniya Kirilina1, Alexnader Jelzow2, Ruediger Bruehl2, Angela Heine1, Michael Niessing1, Arthur M. Jacobs1, Bernd Ittermann2, Heidrun Wabnitz2, Rainer Macdonald2, and Ilias Tachtsidis3
1Free University of Berlin, Berlin, Germany, 2Physikalisch-Technische Bundesanstalt, Berlin, Germany, 3Department Medical Physics and Bioengineering, University College London, London, United Kingdom

Functional near-infrared spectroscopy (fNIRS) is a non-invasive technique for studying the functional organization of the human brain by measuring haemodynamic responses to stimuli in the cerebral cortex. A major challenge of fNIRS is its high sensitivity to haemodynamic fluctuations in the scalp. Here, we combined fNIRS, fMRI and peripheral physiological measurements in order to explore the physiological origin of superficial signals in fNIRS and develop a method to separate them from cortical signals. Using high resolution fMRI data, we show that the main origin of artifacts in fNIRS is task-evoked venous vasoconstriction in the scalp.

14:00 3637.   Small-scale Phase and Magnitude fluctuations in fMRI time series 
Gisela E Hagberg1,2, David Balla3, Hannes M Wiesner4, and Nikos K Logothetis5
1Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, Germany, 2Fondazione Santa Lucia, Rome, Italy, 3High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tubingen, Germany, 4High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Germany, 5Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics

We investigated localized fluctuations during resting state dynamics of 7T phase and magnitude fMRI signals (voxels of 98 and 64nl) at two echo times (13 and 36ms) in rats. We could confirm the presence of TE-dependent signal fluctuations mediated by BOLD susceptibility that was greatest in voxels with strong vascular components and decreased with the distance from such areas. Interestingly, both high phase and magnitude instabilities were observed in the callosal fibers, containing oriented white matter structures. In view of differences in susceptibility between these structures and the surrounding grey matter these fluctuations may result from minute displacements caused for instance by heart pulsations.

14:30 3638.   Fully Automated fMRI Denoising Using Multi-Echo fMRI and TE-Dependent Properties 
Prantik Kundu1, Souheil J Inati1, Jennifer W Evans1, Ziad S Saad2, and Peter A. Bandettini1
1Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States, 2Scientific and Statistical Computing Core, National Institute of Mental Health, Bethesda, MD, United States

A novel configuration of spatial ICA was applied to multi-echo fMRI data. The combination allowed robust, prior-free, and fully automated differentiation of physiological artifact components from BOLD components using an amplitude model for TE-dependence. No anatomical templates, bandpass filtering, physiology regressors, or motion parameters were required. The technique was applied to both task and rest data. Demonstrated is the improvement of including artifact component timecourses as baseline regressors in both activation mapping and seed-voxel functional connectivity.

15:00 3639.   Effect of physiological noise on densely sampled multi-echo fMRI data 
Mark Chiew1,2, and Simon James Graham1,3
1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, 2Rotman Research Institute, Toronto, Ontario, Canada, 3Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Multi-echo functional magnetic resonance imaging (fMRI) is a technique capable of providing enhanced contrast-to-noise ratio (CNR) data in blood oxygenation level dependent (BOLD) imaging experiments. Here, data is presented on the relationship between physiological noise correlations and the CNR benefits of densely sampled multi-echo fMRI over traditional fMRI acquisitions, such as echo-planar imaging. Data from Monte Carlo simulations and experiment are presented, and illustrate a decreasing power law dependence of CNR benefit vs. degree of noise correlation measured across echoes.

Electronic Posters : Functional MRI
Click on to view the abstract pdf and click on to view the video presentation.
fMRI Neuroscience Methods & Applications I

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 57

14:00 3640.   Tumor Induced Alterations in Hemodynamic Responses in BOLD fMRI: Implications in Presurgical Functional Brain Mapping 
Liya Wang1,2, Dandan Chen3, Jeffery Olson4, Shazia Ali1, Tianning Fan2, and Hui Mao1,2
1Radiology, Emory University School of Medicine, Atlanta, GA, United States, 2Center for Systems Imaging, Emory University, Atlanta, GA, United States, 3Physics, Emory University School of Medicine, Atlanta, GA, United States, 4Neurosurgery, Emory University School of Medicine, Atlanta, GA, United States

The blood oxygenation level dependent (BOLD) fMRI has been widely applied in presurgical planning for brain tumor resection. Growth of brain tumor is commonly accompanied by the abnormal blood perfusion, therefore, may lead to an altered BOLD effect and inaccurate measurement of functional maps. This study investigated the effect of the brain tumor to the HDR and BOLD signal time courses in brain tumor patients and its potential impact to the presurgical brain mapping.

14:30 3641.   Neural Correlates of archery Motor Imagery 
Jae-Jun Lee1, Jeehye Seo1, Hui-jin Song1, Seong-Uk Jin1, Ji-Young Kim2, and Yongmin Chang1,3
1medical & Biological Engineering, Kyungpook national university, Daegu, Korea, Republic of, 2school of medicine, Kyungpook national university, Daegu, Korea, Republic of,3Diagnostic Radiology, Kyungpook National University, Daegu, Korea, Republic of

Motor imagery was defined as the metal rehearsal of simple or complex motor acts that is not accompanied by physical movement. Previous studies provide evidence that motor imagery is associated with dynamic changes between performance and the mental rehearsal period that precedes the voluntary movement as an important difference between highly trained athletes and beginners. However, motor imagery of archery and rifle shooting is seldom studied. In the present study, we compared the neural correlates of elite archers and non-archers during mental rehearsal of archery using functional magnetic resonance imaging (fMRI). Our results show that the neural networks of expert archers is more focused and efficiently organized than those of non-archers. The motor programs of experts are more efficiently organized and thus they require less energy to execute. These results are consistent with the notion of relative economy in the cortical processes of expert athletes such as golfers and marksmen, relative to controls, during the specific challenge with which they are highly practiced.

15:00 3642.   fMRI Assessment of Effects of Technique on Neurological Impairment in High School Football Players 
Thomas M Talavage1,2, Evan L Breedlove2, Katherine E Morigaki3, Meghan E Robinson2, Ruwan D Ranaweera1, Eric A Nauman2,4, and Larry J Leverenz3
1School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, 2Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 3Department of Health and Kinesiology, Purdue University, West Lafayette, IN, United States, 4School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States

Concussion in sport has received much recent attention. For two years we have studied high school football players to elucidate consequences of head collisions on brain health. We have observed a new group of impaired players who do not present typical clinical signs of concussion, but can be detected with fMRI. This impairment is correlated with number of blows to the head. We present a case study of two players in our study, whose (non-)alterations in technique appear to correlate with assessment of brain health, suggesting that reducing contact to the head can mitigate brain injury.

15:30 3643.   Training shapes Cerebellum and parieto-frontal network in professional badminton players 
Senhua Zhu1, Xin Di1, Hua Jin2, Pin Wang2, Lei Mo2, Ke Zhou3, Yan Zhuo3, and Hengyi Rao4
1Department of Psychology, Sun Yat-sen University, Guangzhou, Guangdong, China, People's Republic of, 2Department of Psychology, South China Normal University, Guangzhou, Guangdong, China, People's Republic of, 3State Key Laboratory of Brain and Cognitive Science, Beijing, China, People's Republic of, 4Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA, United States

This study used both structural and resting functional MRI and investigated brain differences between 20 professional badminton players and 18 controls with voxel based morphometry (VBM) as well as resting functional connectivity analysis. The findings show that badminton athletes have greater gray matter concentration (GMC) and larger amplitude of low frequency fluctuation (ALFF) in the cerebellum than controls. Athlete group also demonstrated reduced ALFF in left superior parietal lobule, and altered parieto-frontal functional connectivity. Such brain changes may reflect enhanced visuomotor coordination skills in professional players after longitudinal badminton training.

Tuesday May 10th
  13:30 - 15:30 Computer 57

13:30 3644.   Deactivation in Tinnitus patients and Controls during a Tone Discrimination Task studied with fMRI 
Arthur Peter Wunderlich1, Carlos Schönfeldt-Lecuona2, Robert Christian Wolf2, and Wolfgang Freund1
1Dept. for Diagnostic and Interventional Radiology, Univ.-Clinic Ulm, Ulm, Germany, 2Psychiatry Dept., Univ.-Clinic Ulm, Ulm, Germany

Tinnitus patients and healthy controls were studied by means of a tone discrimination task which consisted of tones with differing pitches presented above MR acoustic noise level with a sound-proven MR-compatible headphone. The main finding was deactivation of several cortical and subcortical regions during tone discrimination in healthy controls, while deactivation was not significant in the patient group. An interaction analysis revealed that caudate nucleus, posterior cingulate gyrus and right superior frontal gyrus showed significantly stronger deactivation during tone presentation in controls than in patients. These results are discussed in the light of recently published studies on task-related deactivation.

14:00 3645.   Enhanced Synchronization of Local Hymodynamic Activity in Mesial Temporal Epilepsy Network 
Zhiqiang Zhang1, and Guangming Lu1
1Department of Radiology, Jinling hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China, People's Republic of

Regarding the electrophysiological characteristic of increased local neural synchronization in epilepsy [1], the current study aims to investigate the alteration of the local hemodynamic synchronization in mesial temporal lobe epilepsy (mTLE) using fMRI.

14:30 3646.   Reorganization of functional networks after training with motor imagery in healthy subjects and a single case of lower limb amputation 
Barbara Spano'1, Mara Cercignani1, Marco Bozzali1, Cristiano Pecchioli2, Giacomo Koch2,3, Carlo Caltagirone3,4, and Barbara Marconi2
1Neuroimaging Laboratory, Santa Lucia Foundation, IRCCS, Via Ardeatina 306, 00179 Rome, Italy, Rome, Lazio, Italy, 2Laboratory of Clinical and Behavioral Neurology, Santa Lucia Foundation, IRCCS, Via Ardeatina 306, 00179 Rome, Italy, Rome, Lazio, Italy, 3Department of Neuroscience, University of Rome ‘Tor Vergata’, Viale Oxford 81, 00133 Rome, Italy, Italy, 4Department of Clinical and Behavioural Neurology, Santa Lucia Foundation, IRCCS, Via Ardeatina 306, 00179 Rome, Italy, Rome, Lazio, Italy

This paper describes, using fMRI, the effects of a 2-week training with foot motor imagery in driving cortical reorganization in a group of HS. The results suggest that mental practice with motor imagery is able to induce changes in the pattern of fMRI activations during motor tasks, mainly due to recruitment of association cortex. The effects of motor imagery training were also investigated in a single amputee, showing modifications of the functional activation of the primary motor cortex.

15:00 3647.   Imaginary toe-tapping causes classic motor hand area activation in bilateral upper limb amputees 
Feng Zhao1,2, Hong-Jian He3, Xiao-Jing Yu2, Yi-Xiang Wang1, and Shi-Zheng Zhang2
1Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China, People's Republic of, 2Department of Radiology, Sir Run Run Shaw Hospital, Hang Zhou, Zhe Jiang, China, People's Republic of, 3Bio-X laboratory of Physics Department, Zhejiang University, Hang Zhou, Zhe Jiang, China, People's Republic of

Shift of cortical representation from neighbouring areas to the deafferented cortical representation after amputation has been reported. This study used fMRI to investigate cortical activation in bilateral upper limb amputees when they executed real and imagined toe-tapping. The result revealed the cortical area representing the missing hand was activated by executed and imagined toe tapping in amputees, which wasn¡¯t found in controls. These results suggested that after amputation the cortical reorganization is not limited to the adjacent cortex, and the area representing the missing hand also controls the real foot movement as well as the imagined foot movement.

Wednesday May 11th
  13:30 - 15:30 Computer 57

13:30 3648.   Self-regulation of Amygdala Activation with Real-Time fMRI Neurofeedback 
Vadim Zotev1, Frank Kruger2, Raquel Phillips1, Ruben Alvarez1, W Kyle Simmons1, Pat Bellgowan1, Wayne Drevets1, and Jerzy Bodurka1
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2Department of Molecular Neuroscience, George Mason University, Fairfax, VA, United States

Real-time fMRI neurofeedback allows a person to self-regulate activation in a specific brain region. We explore feasibility of amygdala activity self-regulation in emotional processing. A custom rtfMRI system was used to measure fMRI activation and provide region-of-interest neurofeedback as a variable-height bar. Twenty-one healthy male subjects were asked to feel happy so as to raise the bar. Eleven subjects experienced left amygdala neurofeedback. Ten received "sham" neurofeedback from the horizontal segment of intraparietal sulcus. Increased left amygdala activation was observed across training runs only with real neurofeedback. Our results demonstrate that healthy subjects can self-regulate amygdala function.

14:00 3649.   fMRI of the human amygdala using ultra-high field MRI. Parcellation of emotional human non-linguistic sounds 
Eugenia Solano-Castiella1, Bibek Dhital1, Domenica Wilfling1, Tom Fritz1, Erik Türke1, Enrico Reimer1, Robert Trampel1, and Robert Turner1
1Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Sachsen, Germany

Localization within the body of the amygdala of representations of specific emotions has been little studied. The fMRI spatial resolution commonly available with 3T is prone to susceptibility artifact, and has insufficient spatial precision to distinguish different emotion-related activations. We performed high resolution fMRI at 7T MRI using a 24-channel RF receive coil, with a range of auditory nonverbal emotional human vocalizations. Probabilistic amygdala parcellations, obtained in-vivo, assisted localization of emotions within the amygdala. Use of 7T fMRI and such amygdala maps enables correlation of the functional organization of emotion representation with its anatomical substrate.

14:30 3650.   Spin-Echo BOLD Temporal Dynamics in the Rat Superior Colliculus and Lateral Geniculate Nucleus 
Condon Lau1,2, Jevin W Zhang1,2, Matthew M Cheung1,2, Iris Y Zhou1,2, Kevin C Chan1,2, and Ed X Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of

In rats, the superior colliculus (SC) and lateral geniculate nucleus (LGN) are the main destinations for retinal ganglion cells and are important subcortical structures for vision. BOLD fMRI is used to measure the SC and LGN’s hemodynamic responses, in Sprague-Dawley rats, following short duration (1s) visual stimulation. The most significant responses are concentrated in the contralateral LGN and superficial, medial half of the SC. The SC’s response reaches 25% of maximum amplitude 0.2±0.2s faster than the LGN. However, the LGN’s response diminishes more rapidly. These temporal differences are likely due to vessel dilation rate heterogeneities.

15:00 3651.   Neurophysiological verification that unilateral tactile stimulation evokes contralateral cortical but bilateral thalamic activations 
Basavaraju G Sanganahalli1,2, Peter Herman1,2, Douglas L Rothman2,3, Hal Blumenfeld2,4, and Fahmeed Hyder2,3
1Diagnostic Radiology, Yale University, New Haven, CT, United States, 2Quantitative Neuroscience with Magnetic Resonance in Medicine (QNMR), Yale University, New Haven, CT, United States, 3Diagnostic Radiology and Biomedical Engineering, Yale University, New Haven, CT, United States, 4Neurology, Neurosurgery, Neuroscience, Yale University, New Haven, CT, United States

We used 11.7T fMRI (i.e., BOLD and CBV) and electrophysiology to study thalamocortical activations in anesthetized rats. We detected contralateral cortical but bilateral subcortical activations during forepaw stimulation with fMRI and these localized activations were confirmed by independent neural recordings. There were no significant differences between contralateral and ipsilateral thalamic responses, but the thalamic activations were more pronounced in medial and lateral portions of the laterodorsal thalamic nucleus. These experiments provide early insights into understudied interactions between cortical and subcortical areas and which should provide a mechanistic basis to understand sensory signal processing in the brain.

Thursday May 12th
  13:30 - 15:30 Computer 57

13:30 3652.   Functional Magnetic Resonance Imaging of the Effects of a 60 Hz 3000 μT Magnetic Field on Resting State Brain Blood Flow 
Jodi Miller1,2, Julien Modolo1,2, Michael Corbacio1,2, Daniel Goulet3, Jacques Lambrozo4, Michel Plante3, Martine Souques4, Frank S Prato1,2, Alex W Thomas1,2, and Alexandre W Legros1,2
1Medical Biophysics, University of Western Ontario, London, Ontario, Canada, 2Imaging, Lawson Health Research Institute, London, Ontario, Canada, 3Hydro-Québec,4Service des Études Médicales, EDF

This work investigates the effects of a 60 minute, 60 Hz, 3000 ìT magnetic field exposure on resting state blood flow with ASL. Seven healthy subjects were exposed to the magnetic field and seven subjects were in the sham group. SPM8 was used to analyze the data and found significant regions of activation in both groups within the resting state network. Subjects were unable to detect the magnetic field, as determined by a Field Status Questionnaire. The findings are consistent with EEG studies of MF exposure. Additional subjects are required to further explore the results of this pilot study and to determine the duration of the observed effects.µ

14:00 3653.   BOLD responses according to stimulation orders and manipulation methods 
Geon-Ho Jahng1, Seong-In Bae2, and Sabina Lim2
1Department of Radiology, Kyung Hee University Hospital-Gangdong, Kyung Hee University, Seoul, Seoul, Korea, Republic of, 2Department of Meridian and Acupuncture, Graduate School of Applied Eastern Medicine, Seoul, Seoul, Korea, Republic of

To investigate the BOLD response depending on three parameters, stimulation order, manipulation method and the side (left/right) of acupoint, 14 healthy subjects were recruited and received acupuncture or placebo stimulation on left or right acupoint of ST36. To investigate the effect of the stimulation order, placebo/acupuncture stimulations were performed at the right acupoint and then left acupoint. To investigate the effect of the manipulation method, the needle was inserted and stimulated during only the activation period and then the needle was removed during the baseline scans. BOLD signals were measured at 3T MRI and investigated using SPM8.

14:30 3654.   GABA, glutamate, and perfusion changes during working memory 
Lars Michels1, Ernst Martin1, Peter Klaver2, Richard Edden3, Daniel Brandeis4, Rafael Lüchinger4, David Lythgoe5, Fernando Zelaya5, and Ruth L O'Gorman1
1University Children's Hospital, Zürich, Switzerland, 2Department of Psychology, University of Zürich, Zürich, Switzerland, 3Russell H Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, United States, 4Department of Child and Adolescent Psychiatry, University of Zürich, Zürich, Switzerland,5Centre for Neuroimaging Sciences, Institute of Psychiatry, London, United Kingdom

Recent studies have uncovered a link between resting GABA levels and resting perfusion, BOLD, and changes in cerebral blood volume during stimulation, but the relationship between neurotransmitter and haemodynamic activity during cognition is unknown. This study investigates whether modulations in GABA and glutamate can be detected during working memory (WM) and whether these neurotransmitter changes correlate with perfusion measures. GABA levels increased significantly during the first WM task and then decreased across subsequent task runs. Resting GABA levels correlated inversely to the change in perfusion during WM, and the change in Glx during WM correlated inversely with the resting perfusion.

15:00 3655.   Anesthetic Effects of Propofol on the Brain – Preliminary Results from MRI and MRS in Normal Human Subjects 
Maolin Qiu1, Ramachandran Ramani2, and R Todd Constable1,3
1Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States, 2Anesthesia, Yale University School of Medicine, New Haven, CT, United States,3Biomedical Engineering, Neurosurgery, Yale University School of Medicine, New Haven, CT, United States

Preclinical studies suggest that propofol potentiates GABA activity, promotes GABA release, and inhibits Glutamate release. We employ both MRI and MRS to examine the anesthetic effects of propofol on regional CBF, intrinsic connectivity, and concentration or release of GABA, Glutamate and Glutamine in the normal human brain. Our preliminary data suggest the GABA receptor may be the most sensitive of all neurocepors and play an important role in propofol anesthesia. Propofol affects regional CBF in a drug-specific manner. Although CBF and ICC show similar spatial patterns, CBF is more responsive to changes in brain’s activity than ICC. The robustness of the ICC measure to external anesthetic state suggests that ICC reflect a fundamental and intrinsic property of functional brain organization.

Electronic Posters : Functional MRI
Click on to view the abstract pdf and click on to view the video presentation.
fMRI Neuroscience Methods & Applications II

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 58

14:00 3656.   Event-related Olfactory fMRI 
Xiaoyu Sun1, Christopher W Weitekamp1, Jianli Wang1, Jeffrey Vesek1, and Qing X Yang1,2
1Radiology, Penn State College of Medicine, Hershey, PA, United States, 2Neurosurgery, Penn State College of Medicine, Hershey, PA, United States

In recent olfactory fMRI studies, the subjects were trained to follow instructions for respiration or sniffing to synchronize the odor stimulation. Such methods will fail in studying patients that are not able to follow the instructions. Here we present an event-related paradigm design and post-processing tools for olfactory fMRI without requirement to control the subject’s respiration or sniffing. Our data showed that the subject’s respiratory modulation of the olfactory stimulation paradigm significantly confounded the BOLD signal. The presented event-related design and corresponding data processing method are simple and effective for generating olfactory fMRI results with minimal confounding variability.

14:30 3657.   Dynamic Behavior of BOLD Signal in Olfactory Neural Networks 
Prasanna Karunanayaka1, Christopher W Weitekamp1, Jianli Wang1, Megha M Patel1, Jeffrey Vesek1, Xiaoyu Sun1, Paul J Eslinger2,3, James R Connor4, and Qing X Yang1,4
1Radiology, Center for NMR Research, Penn State University College of Medicine, Hershey, PA, United States, 2Neurology, Penn State University College of Medicine, Hershey, PA, United States, 3Neural & Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, United States, 4Neurosurgery, Penn State University College of Medicine, Hershey, PA, United States

The pattern of BOLD response during the time course of a standardized olfactory stimulation paradigm was investigated and characterized using group independent component analysis (ICA). Group ICA is quickly becoming a preferred functional MRI data analysis technique due to its ability to reveal the underlying networks of the human brain subserving cognitive functions. Group ICA does not require a priori knowledge of the hemodynamic response function (HRF), which may vary across subjects and paradigm conditions.

15:00 3658.   Optimized fMRI imaging protocol and hardware for studying the orbitofrontal cortex in the presence of olfactory stimulation 
Johnny Ng1,2, Heather Berlin3, Wayne Goodman3, Emily Eaves1, David Carpenter1, and Cheuk Tang1,3
1Radiology, Mount Sinai School of Medicine, New York, NY, United States, 2Biomedical Engineering Dept., City College of New York, New York, NY, United States,3Psychiatry, Mount Sinai School of Medicine, New York, NY, United States

Orbitofrontal cortex (OFC) is the key structure affected in obsessive-compulsive disorder (OCD). There is a well-established relationship between olfactory identification and the OFC. There are limited studies in this area with functional magnetic resonance imaging (fMRI), which showed activations in the OFC during olfactory stimulation with pleasant and unpleasant odorant stimuli. There are two main issues which limiting studies in this area: the non-availability of olfactometers and it is problematic imaging OFC due to susceptibility artifacts. The aim of this study is to optimized fMRI imaging protocol for the OFC in OCD patients with the in-house built olfactometer.

15:30 3659.   An MR Compatible Olfactometer for Clinical Research Use 
Johnny Ng1,2, Emily Evaes1, David Carpenter1, and Cheuk Ying Tang1,3
1Dept. Radiology, Mount Sinai School of Medicine, New York, New York, United States, 2Biomedical Engineering Dept., City College of New York, New York, New York, United States, 3Dept. Psychiatry, Mt. Sinai School of Medicine, New York, New York, United States

Interest in the fMRI of the human olfactory system has increased in recent years. The aim of this study is to build a cost effective MR olfactometer suitable for clinical and laboratory environments. An apparatus was built to determine the temporal resolution and the delay time of the custom-built olfactometer. Six healthy subjects participated in testing the olfactometer with six odorant stimuli. The olfactometer has a very short delay time, less than 1 second. Activations were found in the piriform cortex, insular cortex and DLPFC.

Tuesday May 10th
  13:30 - 15:30 Computer 58

13:30 3660.   One Night Total Sleep Deprivation Alters Neural Correlates of Risk-Taking 
Hengyi Rao1,2, Dan Luftig2, Julian Lim2, John A. Detre1, and Daivid F Dinges2
1Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA, United States, 2Unit for Experimental Psychiatry, University of Pennsylvania, Philadelphia, PA, United States

Little is known about the effects of sleep deprivation on neural correlates of risk-taking. The present study used functional MRI and examined the effects of 24hr of total sleep deprivation (TSD) on risk-taking during a modified balloon analog risk task (BART) in 27 normal subjects. One night TSD did not alter the BART risk-taking behavior, nor the risk-induced brain activation patterns. However, TSD decreased insula activation during the loss events and impaired the negative correlation between risk-taking behavior and neural activation in insula and striatum, suggesting that sleep deprivation may alter neural responses during risk-taking before actual behavioral changes.

14:00 3661.   Discriminant analysis and prediction of aMCI subjects and normal controls using encoding and recognition fMRI tasks 
Dietmar Cordes1, Mingwu Jin1, Tim Curran2, Victoria Pelak3, and Rajesh Nandy4
1C-TRIC and Dept. of Radiology, University of Colorado-Denver, Aurora, CO, United States, 2Dept. of Psychology and Neuroscience, University of Colorado-Boulder, Boulder, CO, United States, 3Dept. of Neurology, University of Colorado-Denver, Aurora, CO, United States, 4Depts. of Biostatistic and Psychology, University of California-Los Angeles, Los Angeles, CA, United States

Focusing on activation in subregions of the medial temporal lobe (CA1, CA23DG, SUB, ERC, PRC, FUS, PHC) we used discriminant analysis applied to data from three different memory paradigms to investigate the degree of separation of the aMCI group from the normal control group as a function of the type of paradigm (outdoor pictures, faces-and-occupations, unrelated word pairs) and type of contrast (encoding-control, recognition-control, encoding-recognition, old-control, new-control, old-new). Results indicate optimum separation of groups for the face-and-occupation paradigm for contrast recognition-control. Prediction accuracy using the leave-one-out method is 75% using activations in left CA1, left SUB and left PHC.

14:30 3662.   fMRI of Working Memory in Military Traumatic Brain Injury 
John Graner1, Hai Pan1, Ping-Hong Yeh1, Binquan Wang1, Terrence R Oakes1,2, Wei Liu1,2, Louis M French3, Fletcher Munter2, and Gerard Riedy2,4
1TBI Image Analysis Lab, Uniformed Services University of the Health Sciences / HJF, Bethesda, MD, United States, 2National Capital Neuroimaging Consortium, Walter Reed Army Medical Center, Washington, DC, United States, 3Defense and Veterans Brain Injury Center, Walter Reed Army Medical Center, Washington, DC, United States,4National Intrepid Center of Excellence, Bethesda, MD, United States

Fourteen (14) USA military TBI victims and 11 control subjects underwent fMRI while performing an N-back working memory task. Significant group differences were seen in the cerebellum in the 3-back vs. 1-back contrast. A preliminary investigation of heterogeneity within the group analysis results also suggests greater activation variability in the TBI population that may need to be accounted for when attempting traditional voxel-based group analysis.

15:00 3663.   Working memory impairment in Fibromyalgia patients : fMRI study 
Jeehye Seo1, Jae-jun Lee1, Hui-jin Song1, Seong-Uk Jin1, Ji-Young Kim2, and Yongmin Chang1,3
1Medical & Biological Engineering, Kyungpook National University, Daegu, Korea, Republic of, 2school of medicine, Kyungpook National University, Daegu, Korea, Republic of,3Diagnostic Radiology, Kyungpook National University, Daegu, Korea, Republic of

Fibromyalgia (FM) is a disorder of uncertain etiology characterized by widespread chronic pain, stiffness, and depression. Patients with FM commonly report cognitive complaints, including memory and attention problems. The aim of this study is to elucidate the differences in neural activation related to working memory between FM patients and healthy subjects. We also investigated differences in deactivation of the default network during performance of working memory between two groups. Nineteen FM patients and 22 healthy subjects performed an n-back memory task. We found that healthy subjects showed better performance in terms of accuracy and reaction times during the task. In between-group analyses, FM patients showed reduced activation in the dorsolateral and ventrolateral prefrontal cortex, dorsal cingulate cortex, and inferior parietal cortex. There were no differences in neural deactivation between FM patients and healthy subjects during performance of the n-back test. These results suggest that working memory impairment in FM patients may be attributable to differences in neural activation of the frontoparietal network rather than deactivation of the default network.

Wednesday May 11th
  13:30 - 15:30 Computer 58

13:30 3664.   Investigating the neural base of hearing one's own name by fMRI 
Toshiki Nakane1,2, Miyakoshi Makoto2, Toshi Nakai2, and Shinji Naganawa1
1Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan, 2NCGG, Ohbu, Aichi, Japan

We performed an fMRI study to separate the effect of attention from self-referential processes. For this purpose, three categories of names, namely one's own, repeated, and unfamiliar, were presented as stimuli, followed by high or low beep sounds. Participant's task was to judge one's own/repeated or unfamiliar (attended task), and to judge beep high or low (unattended task). Results showed fCMS involvement when both self-relevance AND attention were needed. We concluded that fCMS is not always sensitive to self-relevance, but only when self-relevance is task-relevant.

14:00 3665.   Empathic brain responses to other's pain was modulated by simple group categorization: An fMRI study 
Yang Hu1,2, Mingxia Fan3, Wenjing Li2, Peijia Huang2, and Zhaoxin Wang1,3
1Institute of Cognitive Neuroscience, Shanghai Key Laboratory of Brain Functional Genomics, East China Normal University, Shanghai, China, People's Republic of,2Department of Psychology, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China, People's Republic of, 3Shanghai Key Laboratory of MRI, East China Normal University, Shanghai, China, People's Republic of

The current study aimed to investigate whether simple group categorization can modulate the neural correlates of empathy for other¡¯s pain using a modified minimal paradigm. Participants were randomly assigned to two groups and were instructed to memorize novel faces of in-/out-group members. They were then sent to the MRI scanner to rate the pain intensity felt by their in-/out-group members. We found that increased activation in right anterior insula was detected while participants see their in-group members receiving painful stimulation in relevant to out-group members, indicating that empathic concern for other¡¯s pain could be modulated by simple group categorization.

14:30 3666.   Disrupted Sensory Projection and Preserved Integrative Network in Propofol-Induced Anesthesia 
Xiaolin Liu1, Kathryn K. Lauer2, Stephen M. Rao3, Shijiang Li1, and Anthony G. Hudetz2
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States, 3Schey Center for Cognitive Neuroimaging, Cleveland Clinic, Cleveland, Ohio, United States

In this study, we described our investigation into the integrative mechanisms of general anesthesia using a compelling verbal memory experimental paradigm that allows neuroimaging characterization of consciousness in waking, anesthesia, and emergence. Our neuroimaging methodology was specifically designed to understand the anesthetic-induced changes of temporal coherence in the brain at different hierarchical levels of the cognitive processing, providing a consistent interpretation with the conception of the anesthetic mechanisms as the information disintegration or the cognitive unbinding. The findings reveal a differential effect of propofol anesthesia on sensory and cognitive systems and provide direct imaging evidence for information disintegration as a mechanism of anesthetic-induced unconsciousness.

15:00 3667.   The Neural Basis of Auditory Processing Disorder 
Vincent Jerome Schmithorst1, Scott Kerry Holland1, and Elena Plante2
1Radiology, Children's Hospital Medical Center, Cincinnati, OH, United States, 2Speech, Language, and Hearing Sciences, University of Arizona, Tucson, AZ, United States

Auditory Processing Disorder (APD) in children is diagnosed on the basis of behavioral tests which can be confounded by attentional or language deficits. We investigate the hypothesis that APD, as currently diagnosed by clinicians, stems from a deficit in cross-modal inhibition (the inhibition of neural processing of other sensory inputs). Performance of behavioral audiology measures was correlated with brain activation during a basic auditory stimulation task using fMRI. Results suggest that performance on tests of auditory processing used to diagnose APD is predicted by cross-modal inhibition of secondary visual areas and the parahippocampal gyrus, associated with repression of irrelevant information.

Thursday May 12th
  13:30 - 15:30 Computer 58

13:30 3668.   Classical music enhances the local functional connectivity density in the brain 
Ruiliang Wang1, Gene-Jack Wang2, Frank Telang3, Rita Z Goldstein4, Nora D Volkow5, and Dardo Tomasi5
1Medical, Brookhaven National Laboratory, Upton, NY, United States, 2Brookhaven Nationa Laboratory, 3medical, Brookhaven National Laboratory, 4Brookhaven National Laboratory, 5National Institute on Drug Abuse, National Institute on Health

We used magnetic resonance imaging and functional connectivity density mapping (FCDM) to map hubs with high local functional connectivity density (lFCD)in 70 healthy men (age: 18-55). Two resting conditions were tested: 1) when the subjects rested with their eyes open (baseline condition), and 2) while they were listening to classical music (music condition). Our findings suggest that in resting conditions, music can increase the local functional connectivity of the brain. These findings are consistent with the involvement of brain regions in processing rhythm (dorsolateral prefrontal and parietal cortices and cerebellum), tonality (temporal and medial prefrontal cortices) and emotions (limbic cortex).

14:00 3669.   Middle Frontal Gyrus as a Potential Neural Indicator for Musical Imagery 
Kirsteen Davidson-Kelly1, Sujin Hong1, Janani Dhinakaran2, Joseph Sanders3, Calum Gray4, Edwin J.R. van Beek4, Neil Roberts4, and Katie Overy1
1Music, University of Edinburgh, Edinburgh, United Kingdom, 2Carl von Ossietzky University of Oldenburgh, Germany, 3Guildhall School of Music & Drama, London, United Kingdom, 4Clinical Research Imaging Centre (CRIC), Queen’s Medical Research Institute (QMRI), University of Edinburgh, Edinburgh, United Kingdom

Musical imagery is an expert learning strategy with potential to enhance performance, reduce physical overuse and decrease anxiety. In this fMRI study we scanned a professional pianist with vivid imagery skills during imagined and simulated motor performance of memorised music. The motor system (SMA, pre-motor cortex, cerebellum) was activated during both tasks, while M1 was activated during performance only. Interestingly, the MFG showed differential activation for imagery (bilateral) and performance (left-sided only), possibly indicating a shift/increase in attention. We conclude that the MFG could provide an index of the effectiveness of musical imagery as a learning strategy.

14:30 3670.   "Dual-Use" fMRI in children: assessing language and visuospatial functions with one task 
Marko Wilke1, Kathina Ebner2, Till-Karsten Hauser3, and Karen Lidzba2
1Pediatric Neurology & Developmental Medicine, University Children's Hospital Tübingen, Tübingen, BW, Germany, 2Pediatric Neurology & Developmental Medicine, University Children's Hospital Tübingen, Tübingen, Germany, 3Diagnostic and Interventional Neuroradiology, Radiological Clinic, Tübingen, Germany

Functional MRI in children is still challenging. We here suggest that appropriately-designed fMRI tasks may be analyzed in the active>control as well as the control>active condition, allowing to assess two cognitive domains in one task. Results from a "dual-use" task assessing language and visuospatial functions are compared with a dedicated task designed to assess visuospatial functions. The implications of such an approach are discussed.

15:00 3671.   Song and Speech – Perception and Covert Production: New Findings using Multi-Voxel Pattern Analysis 
Dirk Goldhahn1, Daniel E Callan2, Gabriele Lohmann1, and Robert Turner1
1Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2ATR Computational Neuroscience Laboratories, Kyoto, Japan

Multi-Voxel Pattern Analysis (MVPA) is a powerful technique for the analysis of fMRI data. It uses the information present in multiple voxels to distinguish between experimental conditions. In this abstract we apply MVPA to examine brain regions differentially involved with listening to and covert production of song relative to speech. We present new findings that univariate analysis failed to discover, and investigate what underlies this discrepancy. As a particular example the superior temporal gyri are discussed, which show highly differential activity for the contrast of covert production of song versus covert production of speech only when using MVPA.

Electronic Posters : Functional MRI
Click on to view the abstract pdf and click on to view the video presentation.
Animal fMRI

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 59

14:00 3672.   BOLD fMRI of the Visual System in Awake and Anesthetized Rats 
Der-Yow Chen1, Stephen Dodd1, Afonso Silva1, and Alan Koretsky1
1LFMI, NINDS, NIH, Bethesda, MD, United States

In the present study, we compare the BOLD fMRI of the visual system in awake and alpha-chloralose anesthetized rats. A head post was implanted to minimize the head motion and rats were trained to accustom to a restrainer. Brain activity in response to various frequencies of flashing light was explored. Awake rats showed significant fMRI activation in the lateral geniculate nucleus, superior colliculus, and the visual cortex, especially in response to high frequencies. On the contrary, less activation were found in these regions of anesthetized rats. These findings indicate that fMRI experiments in awake rats may be more appropriate to study the function of visual system.

14:30 3673.   Neurophysiological underpinnings of ketamine-induced negative BOLD response and interactions with anaesthesia 
Naranjargal Dashdorj1, Mirjam I Schubert1, Malcolm Prior2, Rob Mason3, and Dorothee P Auer1
1Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Brain and Body Centre, University of Nottingham, Nottingham, United Kingdom, 3School of Biomedical Sciences, University of Nottingham, Nottingham, United Kingdom

Pharmacological magnetic resonance imaging (phMRI) is an increasingly popular tool to study drug effects on brain function using the blood oxygen level dependent (BOLD) signal. However, the nature of the drug induced BOLD signal change is still not well understood; in particular its relationship with the underlying neural activity. Additionally, the majority of animal phMRI studies require anaesthesia, which may interact with the investigated drug. The neurophysiological underpinnings of BOLD signal changes were directly studied in few hallmark studies. It remains however unclear whether a similar relation between LFP and BOLD signal change exist for pharmacological fMRI under different anaesthetic protocol. In this study we compared ketamine-induced BOLD changes with electrophysiological recordings in rodent brain under two different anaesthetic protocols.

15:00 3674.   Ketamine-evoked Functional Connectivity Changes in Isoflurane Anaesthetised Rats 
Naranjargal Dashdorj1, Mirjam I Schubert1, Rob Mason2, and Dorothee P Auer1
1Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2School of Biomedical Sciences, University of Nottingham, Nottingham, United Kingdom

In recent years synchronised low-frequency spontaneous fluctuations detected by fMRI BOLD signal has been widely applied to study functional connectivity networks in human subjects. Although, the nature of functional connectivity detected by spontaneous BOLD fMRI and its underlying neural correlates have not been well understood yet. Animal studies provide wider possibility of invasive and non-invasive methods. Hence, the applications of BOLD fMRI functional connectivity in animal studies are expected to facilitate in-depth understanding of low-frequency BOLD fluctuations. In particular, using psychoactive compound to study changes in functional connectivity would allow us to study changes in a given animal on same background neural activity. This study examined the spatiotemporal dynamics under isoflurane anaesthesia.

15:30 3675.   Alternating Phase Coherence of Spontaneous Hemodynamic Oscillation is Sensitive to Anesthesia Levels 
Xiao Liu1, Xiao-Hong Zhu1, Yi Zhang1, and Wei Chen1
1CMRR, Radiology, University of Minnesota, Minneapolis, MN, United States

In this study, we observed strong ~0.1 Hz hemodynamic (CBF and BOLD) oscillations in cats anesthetized with alpha-chloralose. The inter-hemispheric (i.e., left versus right V1, and left versus right LGN) phase coherence of hemodynamic oscillations is alternating between positive and negative values over time. Moreover, the relative proportions of positive and negative correlations changes with anesthesia level with more negative correlations under the deeper anesthesia. The results may suggest that the increased anesthesia level can impair the brain’s capability of synchronizing activity across different regions and result in less phase coherence even at the early thalamic brain regions.

Tuesday May 10th
  13:30 - 15:30 Computer 59

13:30 3676.   BOLD fMRI investigation of rat auditory system 
Matthew Man Hin Cheung1,2, Iris Y Zhou1,2, Kevin C. Chan1,2, Frank Y Lee1,2, Leon C. Ho1,2, Condon Lau1,2, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China, People's Republic of

In this study, auditory system was investigated in rodents by BOLD fMRI at 7T. Auditory pathway and various components were revealed by BOLD responses in agreement with the known auditory neuroanatomy by other methods. Tonotopic mapping in inferior colliculus was also demonstrated for the first time by fMRI. Such non-invasive study of functional hemodynamic responses in auditory system will provide a valuable tool in hearing research of normal and diseased models. This was by far the first BOLD fMRI study of rodent auditory system.

14:00 3677.   BOLD Response Dependence on the Stimulation Light Intensity in the Rat Superior Colliculus 
Jevin W Zhang1,2, Condon Lau1,2, Matthew M Cheung1,2, Kyle Xing1,2, Iris Y Zhou1,2, Kevin C Chan1,2, and Ed X Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of

In rats, the superior colliculus (SC) is the main destination for retinal ganglion cells and is an important subcortical structure for vision. Its light intensity dependence has not been extensively studied with functional imaging. BOLD fMRI is used to measure the SC’s hemodynamic response, in Sprague-Dawley rats, to visual stimulation at five intensity levels (4.2x10-3 to 0.74W/m2). Significant responses are observed at all intensity levels. Less of the SC responds to 4.2x10-3W/m2 stimulation than to higher intensity stimuli (p<0.05). The response amplitude during 4.2x10-3W/m2 stimulation is also significantly lower than during 7.6x10-2 and 0.23W/m2 stimulation (p<0.05).

14:30 3678.   BOLD fMRI Study of the Rat Superior Colliculus Responding to a Moving Visual Stimulus 
Condon Lau1,2, Jevin W Zhang1,2, Matthew M Cheung1,2, Kyle Xing1,2, Iris Y Zhou1,2, Kevin C Chan1,2, and Ed X Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of

In rats, the superior colliculus (SC) is the main destination for retinal ganglion cells and is an important subcortical structure for vision. Many of its neurons are highly sensitive to moving objects. BOLD fMRI is used to measure the SC’s hemodynamic response, in Sprague-Dawley rats, to a visual stimulus moving at five speeds between 7 and 164°/s. Significant responses are observed at all speeds tested. The maximum response amplitude occurred at 41 and 82°/s and the minimum at 164°/s. The number of responsive voxels was lowest at 164°/s. These findings appear to be in agreement with electrical recording studies.

15:00 3679.   BOLD signal differences in the somatosensory and visual pathways 
Daniil Aksenov1,2, Limin Li1,2, Michael Miller1,2, and Alice Wyrwicz1,2
1NorthShore University Health System, Evanston, IL, United States, 2Pritzker School of Medicine, University of Chicago, Chicago, IL, United States

In order to examine the local differences in BOLD signal, fMRI data were obtained from awake rabbits using either whisker or visual stimulation, and the BOLD responses in cortical and subcortical structures of the pathways were compared within and between each sensory system. Early results reveal striking differences in the shape of BOLD time courses in terms of adaptation (i.e., decrease to a plateau following an initial peak) between in the visual and whisker pathways. These results suggest that visual cerebral cortical versus subcortical and whisker cortical regions are characterized by different hemodynamic properties.

Wednesday May 11th
  13:30 - 15:30 Computer 59

13:30 3680.   Anatomical, BOLD, Blood Flow MRI of Non-Human Primate (Baboon) Retina 
Yi Zhang1,2, Hsiao-Ying Wey1,2, Oscar San Emeterio Nateras2, Qi Peng1,2, and Timothy Q. Duong1,2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, 2Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States

In rodent models, layer-specific resolution of anatomical, blood flow and functional MRI has been reported. As a first step toward translation, we investigated the feasibility of multimodal retinal MRI on anesthetized large non-human primate (baboon) using a standard clinical 3-Tesla scanner. Baboon was chosen because it has large eyes and better recapitulates human retinal diseases. Anesthesia and paralysis were used to exclude movement artifacts, such that we could focus on evaluating hardware feasibility and pulse sequence parameters for high-resolution multimodal MRI of the retina on a clinical scanner. These findings offer encouraging data to explore human applications.

14:00 3681.   BOLD-fMRI study of Effect of Dark-rearing on Postnatal Visual Development 
Joe Shi Cheng1,2, Kevin C. Chan1,2, Iris Y Zhou1,2, Matthew M Cheung1,2, Condon Lau1,2, and Ed X Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrial and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of

Environmental inputs play a significant role in visual system development. However, current studies on the effects of visual input deprivation (dark-rearing) mainly use histological, electrophysiological, and optical imaging techniques. The result of this study demonstrated for the first time an in vivo approach for simultaneously assessing the functional developmental changes in rat cortical and subcortical visual system, and found that the visual cortex’s BOLD response is reduced by dark-rearing (p<0.05) while that of the subcortical visual nuclei (superior colliculus and lateral geniculate nucleus ) are less affected.

14:30 3682.   Optogenetically induced BOLD of excitatory neurons in the mouse hippocampus at 9.4T: identification of a hippocampal network 
Wolfgang Weber-Fahr1, Alexander Sartorius2, Natlia Gass1, Zhijun Li3, and Wolfgang Kelsch2,3
1Neuroimaging, Central Institute of Mental Health, Mannheim, Germany, 2Psychiatry, Central Institute of Mental Health, Mannheim, Germany, 3Clinical Neurobiology, Ruprecht-Karls-Universität, Heidelberg, Germany

It was shown recently in rats that BOLD activation in a particular region can be caused by optogenetic stimulation. In this study we were interested in the hippocampal network in mice and induced expression of channelrhodopsin-2 in Ca2+/calmodulin-dependent protein kinase II-expressing neurons by viral injection. Laser stimulation was periodically applied through an optical fiber in the left hippocampus with a block design while fMRI data was aquired. We found activation in a large area of the targeted hippocampus. Interestingly, we also we found a corresponding significant activation in areas outside the stimulated region in the primary somatosensory and motor cortices.

15:00 3683.   Study of Brain Activation in Small Animals using PET/MR Imaging 
Hans F Wehrl1, Florian C Maier1, Petros Martirosian2, Gerald Reischl3, Fritz Schick2, and Bernd J Pichler1
1Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, University of Tuebingen, Tuebingen, Germany, 2Section on Experimental Radiology, University of Tuebingen, Tuebingen, Germany, 3Radiopharmacy and PET-Center, University of Tuebingen, Tuebingen, Germany

Brain activation was studied by small animal [15O]H2O PET and BOLD fMRI measurements. Qualitatively PET and MR activation information correlates, however discrepancies are observed concerning the statistical significance, spatial extend as well as spatial location of the activation centers, which arise from methodological as well as physiological differences between the observed PET and MR signal. These studies open the scene for further research of brain metabolism using PET/MR imaging techniques, combining the sensitivity of PET with the the functional imaging capabilities of MR.

Thursday May 12th
  13:30 - 15:30 Computer 59

13:30 3684.   Rat Brain Possesses a Default Mode Network 
Hanbing Lu1, Qihong Zou1, William Rea1, Elliot A Stein1, and Yihong Yang1
1National Institute on Drug Abuse, NIH, Baltimore, MD, United States

We have identified coherent, spontaneous activity within a specific brain network in rats that mirrors the default mode network (DMN) previously reported in human and non-human primates, suggesting that operations performed by the DMN may be a fundamental physiological process in the mammalian brain. Our data raise interesting questions about the functions of DMN across species, and open novel opportunity to investigate the physiological basis of DMN using rodent model.

14:00 3685.   resting state networks in (transgenic) mice: differential effects of genetic background, sensory stimulation, and pharmacological intervention 
Silke Kreitz1, Cornelia Heindl-Erdmann1, Roland Axmann2, Jochen Zwerina2, Josef Penninger3, Georg Schett2, Kay Brune1, and Andreas Hess1
1Institute for Pharmacology and Toxicology, FAU Erlangen-Nuremberg, Erlangen, Germany, 2Internal Medicine 3, Rheumatology and Immunology, FAU Erlangen-Nuremberg, Erlangen, Germany, 3Institute of Molecular Biology, Austrian Academy of Sciences, Vienna, Austria

Resting state analysis of brain activity in (transgenic) mice was performed before and after peripheral heat stimulation. “Painless” mice (DREAM -/-), having permanent analgesia due to modification of the dynorphin pain pathway, showed no change in their resting state network connectivity after the painful stimulation compared to wild-type mice. Pharmacological compensation of their genetic modification, reestablished plastic effects of the painful stimulation on the resting state network. These results demonstrate the usefulness of non invasive fMRI in transgenic mice and molecular defined pharmacological intervention to further investigation of functional connectivity in pain research.

14:30 3686.   Resting-state Functional Connectivity Alterations after Corpus Callosotomy in Rats 
Iris Yuwen Zhou1,2, Y X Liang3, Kevin C. Chan1,2, Matthew M. Cheung1,2, Condon Lau1,2, K F So3, and Ed X Wu1,2
1Laboratory of Biomedical and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 3Department of Anatomy, The University of Hong Kong

Resting-state fcMRI has been increasingly used in the diagnosis of a variety of brain diseases. However, the underlying mechanism of the spontaneous fluctuations in fcMRI signals remains largely unexplored. In this study, we employed a well-controlled animal model of corpus callosotomy to evaluate the role of corpus callosum (CC) in the interhemispheric functional connectivity. It was found that a strikingly loss of interhemispheric correlation after the complete transection of CC while the intrahemispheric connections was preserved and seemed to be expanded. The results of this study provide direct evidence of the role of CC in spontaneous neural activity.

15:00 3687.   Restoration of Interhemispheric Resting-State Connectivity in S1FL Following Median Nerve Injury and Surgical Repair 
Christopher Paul Pawela1,2, Bharat B Biswal3, Rupeng Li2, Anthony G Hudetz4, and James S Hyde2
1Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, United States, 2Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 3Department of Radiology, University of Medicine and Dentistry of New Jersey, Newark, NJ, United States, 4Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States

Resting-State Functional Connectivity MRI (fcMRI) is finding application in studying a variety of brain disorders. The underlying physiological basis of the BOLD resting-state fluctuations is still unknown. In this study, manipulation of the peripheral nervous system is performed to modify signal input into the thalamocortical system and disrupt interhemispheric correlation of the sensorimotor system. This study demonstrates the bilateral nature of resting-state correlation and may provide insight into the phenomenon.