PT  - JOURNAL ARTICLE
AU  - Olivier Chevallier
AU  - Nan Zhou
AU  - Jian He
AU  - Romaric Loffroy
AU  - Yi-Xiáng J. Wang
TI  - IVIM parameters have good scan-rescan reproducibility when evidential motion contaminated and poorly fitted image data are removed
AID  - 10.1101/179440
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 179440
4099  - http://biorxiv.org/content/early/2017/11/22/179440.short
4100  - http://biorxiv.org/content/early/2017/11/22/179440.full
AB  - Background Intravoxel Incoherent Motion (IVIM) diffusion MRI is a promising technique for liver pathology evaluation, but this technique’s scan-rescan reproducibility has been reported to be unsatisfactory.Objective To understand whether IVIM MRI parameters for liver parenchyma can be good after removal of motion contaminated and/or poorly fitted image data.Material and Methods Eighteen healthy volunteers had liver scanned twice at the same session to assess scan-rescan repeatability, and again in another session after an average interval of 13 days to assess reproducibility. Diffusion weighted image were acquired with a 3T scanner using respiratory-triggered echo-planar sequence and 16 b-values (0 to 800 s/mm2). Measurement was performed on the right liver with segmented-unconstrained least square fitting. Image series with evidential anatomical mismatch, apparent artifacts, and poorly fitted signal intensity vs. b-value curve were excluded. A minimum of three slices was deemed necessary for IVIM parameter estimation of a liver.Results With total 54 examinations, 6 scans did not satisfy inclusion criteria, leading to a success rate of 89%; and 14 volunteers were finally included. With each scan a mean of 5.3 slices (range: 3-10 slices) were utilized for analysis. Using threshold b-value=80s/mm2, the coefficient of variation and within-subject coefficient of variation for repeatability and reproducibility were: 2.86% and 4.24% for Dslow, 3.81% and 4.24%, for PF, 18.16% and 24.88% for Dfast; and those for reproducibility were 2.48% and 3.24% for Dslow; 4.91% and 5.38% for PF; 21.18% and 30.89% for Dfast.Conclusion IVIM parameter scan-rescan reproducibility can be potentially good.