Background: The perfusion-related diffusion coefficient obtained from triexponential diffusion analysis is closely correlated with regional cerebral blood flow (rCBF), as assessed by arterial spin labeling (ASL) methods. However, this provides only a semiquantitative measure of rCBF, thereby making absolute rCBF quantification challenging.
Purpose: To obtain rCBF in a noninvasive manner using a novel diffusion imaging method with phase contrast (DPC), in which the total CBF from phase-contrast (PC) MRI was utilized to convert perfusion-related diffusion coefficients to rCBF values.
Study type: Prospective.
Subjects: Eleven healthy volunteers (nine men and two women; mean age, 23.9 years) participated in this study.
Field strength/sequence: A 3.0 T, single-shot diffusion echo-planar imaging with multiple b-values (0-3000 s/mm2 ), PC-MRI, pulsed continuous ASL, and 3D T1 -weighted fast field echo.
Assessment: rCBF and its correlations in the gray matter (GM) and white matter (WM) were compared between DPC and ASL methods. rCBF in the GM and WM and the GM/WM ratio were compared with the literature values obtained using [15 O]-water positron emission tomography (15 O-H2 O PET).
Statistical tests: Spearman's correlation coefficient and Wilcoxon signed-rank test were used. Significance was set at P < 0.05.
Results: A significant positive correlation between DPC and ASL in terms of rCBF was observed in GM (R = 0.9), whereas the correlation between the two methods was poor in WM (R = 0.09). The rCBF in GM and WM and the GM/WM ratio obtained using DPC were consistent with the literature values assessed using 15 O-H2 O PET. The rCBF value obtained using DPC was significantly higher in the GM and WM than that using ASL.
Data conclusion: DPC enabled noninvasive quantification of rCBF.
Evidence level: 2 TECHNICAL EFFICACY: Stage 1.
Keywords: cerebral blood flow; diffusion-weighted imaging; intravoxel incoherent motion; perfusion-related diffusion; phase contrast.
© 2021 International Society for Magnetic Resonance in Medicine.