Repeatability and reproducibility comparisons of liver IVIM imaging with free‐breathing or respiratory‐triggered sequences

作者：Xinming Li, Fu‐Zhao Ma, Xianyue Quan, Xu‐Chang Zhang, Ben‐Heng Xiao, Yi-Xiang Wang · 发表于：NMR in Biomedicine · 年份：2023 · DOI：10.1002/nbm.5080 · 被引用次数：10 · 研究领域：MRI in cancer diagnosis、Advanced MRI Techniques and Applications、Advanced Neuroimaging Techniques and Applications

For liver intravoxel incoherent motion (IVIM) data acquisition, respiratory‐triggering (RT) MRI is commonly used, and there are strong motivations to shorten the scan duration. For the same scan duration, more b values or higher numbers of excitations can be allowed for free‐breathing (FB) imaging than for RT. We studied whether FB can be used to replace RT when careful IVIM image acquisition and image processing are conducted. MRI data of 22 healthy participants were acquired using a 3.0 T scanner. Diffusion imaging was based on a single‐shot spin‐echo‐type echo‐planar sequence and 16 b values of 0, 2, 4, 7, 10, 15, 20, 30, 46, 60, 72, 100, 150, 200, 400, and 600 s/mm 2 . Each subject attended two scan sessions with an interval of 10–20 days. For each scan session, a subject was scanned twice, first with RT and then with FB. The mean image acquisition time was 5.4 min for FB and 10.8 min for RT. IVIM parameters were calculated with bi‐exponential model segmented fitting with a threshold b value of 60 s/mm 2 , and fitting started from b = 2 s/mm 2 . There was no statistically significant difference between IVIM parameters measured with FB imaging or RT imaging. Perfusion fraction ICC (intraclass correlation coefficient) for FB imaging and RT imaging in the same scan session was 0.824. For perfusion fraction, wSD (within‐subject standard deviation), BA (Bland–Altman) difference, BA 95% limit, and ICC were 0.022, 0.0001, −0.0635~0.0637, and 0.687 for FB and 0.031, 0.0122, −0.07...