Premium
Automatic repositioning of MRSI voxels in longitudinal studies: Impact on reproducibility of metabolite concentration measurements
Author(s) -
Ratai EvaMaria,
Hancu Ileana,
Blezek Daniel J.,
Turk Katherine W.,
Halpern Elkan,
González R. Gilberto
Publication year - 2008
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21365
Subject(s) - voxel , reproducibility , magnetic resonance spectroscopic imaging , computer science , nuclear medicine , artificial intelligence , medicine , magnetic resonance imaging , radiology , mathematics , statistics
Purpose To study an automatic repositioning method to reduce variability in longitudinal MRSI exams based on a priori image registration. Longitudinal proton MR spectroscopic imaging ( 1 H MRSI) exams to study the effects of disease or treatment are becoming increasingly common. However, one source of variability in such exams arises from imperfect relocalization of the MRSI grid in the follow‐up exams. Materials and Methods Six healthy subjects were each scanned three times during the course of 1 day. In each follow‐up exam a manually placed MRSI grid was acquired in addition to the automatically repositioned MRSI grid. Then coefficients of variance between baseline and follow‐up scans were calculated for N‐acetylaspartate, creatine, and choline. In addition, the overall MRSI grid overlap and individual voxel overlaps were also calculated for both the visually and automatically repositioned voxels. Results Streamlined workflow, reduced variability of metabolite concentration measurements, and increased voxel overlaps are noted when this automatic repositioning procedure is compared to the visual MRSI grid repositioning approach. Conclusion Our results suggest that this approach is able to improve reproducibility in longitudinal MRS exams. J. Magn. Reson. Imaging 2008;27:1188–1193. © 2008 Wiley‐Liss, Inc.