Investigation of BOLD contrast in fMRI using multi-shot EPI.
High resolution volume coverage of the brain in fMRI studies can be accomplished using multi-slice, multi-shot EPI. We demonstrate that the optimum contrast sensitivity in BOLD based fMRI experiments using multi-shot EPI is achieved by using the shortest possible TR values between segments and the longest tolerable echo train length. For a fixed paradigm time, acquiring the largest number of images under these conditions yields the best statistical detection thresholds. For a multi-slice multi-shot EPI fMRI study, the best approach is to perform the acquisition of all the segments in a single slice before continuing on to each of the slices in turn. Our results regarding the number of shots and TR are also applicable to other multi-shot techniques such as interleaved spirals.
Menon
R S
RS
The John P. Robarts Research Institute, Department of Diagnostic Radiology and Nuclear Medicine, The University of Western Ontario, London, Canada. rmenon@irus.rri.uwo.ca
Thomas
C G
CG
Gati
J S
JS
D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012680:Sensitivity and Specificity
D010100:Oxygen