ELECTRONIC POSTER - ismrm

Thursday 13:30-15:30 Computer 128
13:30 5147. The Effect of Tissue Erosions and Segmentation Probability Thresholds on
Magnetisation Transfer Ratio Histograms
Daniel J. Tozer 1 , Sameeha Fallatah 1 , Leonora Finisku 1 , David H. Miller 1
1 NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom
Magnetisation transfer ratio histograms are widely used in the study of multiple sclerosis. Histogram generation methods may affect
the parameters extracted. This work investigates whether the tissue probability threshold used in segmentation and the number of
erosions applied to the tissue segments effect the histogram parameters and whether this differs between healthy controls and multiple
sclerosis patients. It is found that the number of erosions has more of an effect on the histogram parameters than the probability
threshold used, in particular the first erosion. There were some differences between the behaviour in patients and controls, but this was
not systematic.
14:00 5148. Fast Bound Pool Fraction Quantification Using Stimulated Echoes
Michaela Soellinger 1 , Christian Langkammer 1 , Thomas Seifert-Held 1 , Franz Fazekas 1 ,
Stefan Ropele 1
1 Department of Neurology, Medical University of Graz, Graz, Austria
The bound proton pool fraction is linked to the lipid and protein content of myelin. Therefore, fast mapping methods are required for
patient studies and clinical routine. We introduce a sequence allowing whole brain BPF determination in within clinically feasible
time (~5 min for 11 slices). The method is based on the labelling of the free water pool with stimulated echo amplitude modulation
(STEAM). The herewith presented approach was validated with bovine serum albumin (BSA) probes and successfully tested in three
healthy volunteers. Regional analysis of white matter was in good agreement with published BPF values.
14:30 5149. Correlation Time Diffusion MRI of Mouse Liver at 11.7T: Magnetization Transfer
Effects
Hernan Jara 1 , Stephan W. Anderson 1 , Osamu Sakai 1 , Jorge A. Soto 1
1 Boston University School of Medicine, Boston, MA, United States
Purpose: To map the correlation time diffusion coefficient (CT-D) of ex vivo liver samples imaged at 11.7T and to compare results
quantitatively vs. the standard pulsed-field gradient (PFG-D) diffusion MRI. Methods: A CT-D algorithm was applied to mouse liver
images obtained with Tandem-TSE at 11.7T. Results: Excellent quantitative agreement was found between this non-PFG diffusion
technique vs. the standard PFG diffusion technique. Conclusion: CT-D diffusion MRI is a viable alternative to standard PFG-diffusion
MRI that produces higher SNR and is less demanding on the imaging gradients. This work could have implications for diffusion MRI
microscopy.
15:00 5150. Novel Magnetization-Prepared Multi-Slice Multi-Shot EPI Pulse Sequence for
T1rho Quantitation
Eric T. Han 1 , Weitian Chen 1 , Ajit Shankaranarayanan 1
1 Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States
There are numerous clinical scenarios where evaluation of T1ñ in a focal region-of-interest is desired. In such cases, a quantitative
multi-slice 2D T1ñ approach may be more appropriate and time-efficient than a 3D technique. We propose a novel 2D multi-slice
T1ñ imaging sequence that overcomes many of the shortcomings of current multi-slice T1ñ methods. Using this sequence, in vivo T1ñ
maps of the knee, spine, and brain are acquired.