TRADITIONAL POSTER - ismrm

Poster Sessions
lung cancer. A respiratory-gated multi-echo gradient-echo technique is demonstrated as a feasible method to quantify T2* values of lung tumors. The
response of tumor T2* measurements to an oxygen-breathing challenge should be sensitive to tumor hypoxia and could therefore serve as a prognostic
indicator before therapy.
1094. Interleaved T1- And T2*-Weighted Imaging Can Evaluate Dynamic Oxygen Challenge: A Feasibility
Study
Yao Ding 1 , Ralph P. Mason 1 , Qing Yuan 1 , Rami R. Hallac 1 , Roderick W. McColl 1 , Robert D. Sims 1 , Paul T.
Weatherall 1
1 Radiology, UT southwestern medical center at Dallas, Dallas, TX, United States
The present 2D respiratory-triggered interleaved T1- and T2*-weighted sequence provides a promising means to study TOLD and BOLD response
simultaneously without the need for registration and with good temporal resolution (less than 30 seconds).
1095. Does the BOLD Response to EPI-Related Acoustic Noise Change Over an FMRI Experiment?
Oliver Hinds 1 , Aaron Hess 2 , M. Dylan Tisdall 3 , Todd Thompson 1 , Hans Breiter 3 , André van der Kouwe 3
1 A. A. Martinos Imaging Center at the McGovern Institute, Massachusetts Institute of Technology, Cambridge, MA, United States;
2 Human Biology, University of Cape Town, Cape Town, South Africa; 3 A. A. Martinos Center for Biomedical Imaging, Department
of Radiology, MGH, Harvard Medical School, Charlestown, MA, United States
If the BOLD response to EPI acoustic noise changes over the time course of a standard fMRI experiment, both Type I and Type II errors can be made in
fMRI group analysis. We used a pulse sequence based on single-voxel functional spectroscopy to silently measure the BOLD response induced by EPI-like
scanner noise over about 40 minutes. No significant habituation or facilitation with respect to the scanner noise was found over that time. This result
eliminates a possible confound for auditory and speech neuroimaging studies, especially those involving learning.
1096. Reproducibility of FMRI Localisation Within the Human Somatosensory System.
Rishma Vidyasagar 1 , Laura M. Parkes 2,3
1 MARIARC, University of Liverpool , Liverpool, Merseyside, United Kingdom; 2 School of Cancer and Imaging Sciences, University
of Manchester; 3 Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom
fMRI data can often be affected by issues such as registration and scanner system errors. These issues affect interpretation of data and is especially relevant
in longitudinal studies depending on accurate reproducibility of data. This study compared different analysis techniques of fMRI data to establish the most
accurate means of overcoming these issues by focusing on fMRI data from the somatosensory system in the human brain.
1097. Real Time FMRI – Avoiding Drift Using Answer Blocks
Thomas WJ Ash 1 , T Adrian Carpenter 1 , Guy B. Williams 1
1 Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom
Where real time fMRI needs solely a digital (e.g., task vs rest or task 1 vs task 2) output, answer blocks can provide a means of circumventing the drift that is
known to affect results. Using answer blocks, we improve performance compared to averaging over a block using classifiers from 53% to 84%, and using
ROI techniques from 53% to 64%. This also gives a means for presenting probabilistic outputs to class membership, which are vital when dealing with
impaired patients, for whom this kind of technique may be their only communication channel.
1098. Simultaneous Optical Tomography (OT) and FMRI with and Without Task Activation
Jan Mehnert 1,2 , Christoph Schmitz 2,3 , Harald E. Möller 1 , Hellmuth Obrig 1,2 , Karsten Müller 1
1 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2 Berlin Neuroimaging Center, Charité University
Hospital Berlin, Berlin, Germany; 3 NIRx Medizintechnik GmbH, Berlin, Germany
Correlation analysis of low-frequency fluctuations in blood-oxygen level dependent (BOLD) fMRI data is known to yield functional connectivity maps. The
procedure, also referred to as ‘resting-state connectivity’, has previously been applied to optical tomography (OT) data using dense probe arrays. Here, we
assess whether a sparser topographical sampling still yields results that are comparable to the ‘gold standard’ of resting-state network assessment, i.e. fMRI.
In a first step, we used a subset of optical fibers (2-3cm inter-optode distance) covering both motor cortices and combined OT with concurrent fMRI
measurements to cross-validate our resting-state data analysis.
1099. High Resolution Functional MR Venography with 7T MRI
Seo-Hyun Lee 1 , Chang-Ki Kang 1 , Chan-A Park 1 , Young-Bo Kim 1 , Zang-Hee Cho 1,2
1 Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea, Republic of; 2 Department of
Radiological Sciences, University of California, Irvine, Irvine, CA, United States
MR venography using susceptibility weighted imaging (SWI) has been utilized for the study of venous morphology and the venous vasculature in disease
states. However, SWI has poor intrinsic temporal resolution, thus it is not able to provide information on high temporal dynamic changes within a few
seconds that occur during neural stimulation. In this paper, we proposed a technique, which we labeled functional MR venography (fMRV), to investigate
the venous dynamic response to external stimulation using 7T MRI. The presented result suggests that this technique may provide important, more precise
information regarding the venous response and its role in the overall hemodynamic response to neural activity with high spatial (0.5 isotropic) and temporal
(3 seconds) resolution.
1100. The Orbitofrontal FMRI Experiment with Correction of the Susceptibility Artifact
Sung Suk Oh 1 , SungDae Yun 1 , Bumseok Jeong 2 , HyunWook Park 1
1 Department of Electrical Engineering, KAIST, Daejeon, Korea, Republic of; 2 Department of Psychiatry, Eulji University Hospital,
Daejeon, Korea, Republic of
The signal loss by the susceptibility artifact makes it difficult analyze the fMRI data of the orbitofrontal region of the brain. In addition, an EPI sequence,
which is used in many fMRI experiments, has the geometric distortion and Nyqust ghosts. For the fMRI experiment with correction of these artifact and