Can the low and high b-value distribution influence the pseudodiffusion parameter derived from IVIM DWI in normal brain?

• Published in: BMC medical imaging 2020-02, Vol.20 (1), p.14-14, Article 14
• Main Authors: Hu, Yu-Chuan, Yan, Lin-Feng, Han, Yu, Duan, Shi-Jun, Sun, Qian, Li, Gang-Feng, Wang, Wen, Wei, Xiao-Cheng, Zheng, Dan-Dan, Cui, Guang-Bin
• Format: Article
• Language: English
• Subjects: B-value; Brain; Brain research; Diagnostic imaging; Diffusion coefficient; Diffusion rate; Diffusion weighted imaging; Driving while intoxicated; Ethical standards; Ethics; Informed consent; Intravoxel incoherent motion; Magnetic resonance imaging; Neuroimaging; Number of excitation; Parameter estimation; Parameters; Perfusion; Pseudodiffusion; Substantia alba; Substantia grisea; Variance analysis
• ISSN: 1471-2342; 1471-2342
• DOI: 10.1186/s12880-020-0419-0

Our study aims to reveal whether the low b-values distribution, high b-values upper limit, and the number of excitation (NEX) influence the accuracy of the intravoxel incoherent motion (IVIM) parameter derived from multi-b-value diffusion-weighted imaging (DWI) in the brain. This prospective study was approved by the local Ethics Committee and informed consent was obtained from each participant. The five consecutive multi-b DWI with different b-value protocols (0-3500 s/mm ) were performed in 22 male healthy volunteers on a 3.0-T MRI system. The IVIM parameters from normal white matter (WM) and gray matter (GM) including slow diffusion coefficient (D), fast perfusion coefficient (D*) and perfusion fraction (f) were compared for differences among defined groups with different IVIM protocols by one-way ANOVA. The D* and f value of WM or GM in groups with less low b-values distribution (less than or equal to 5 b-values) were significantly lower than ones in any other group with more low b-values distribution (all P  0.05). In addition, no significant differences in the D, D* and f value of WM or GM were found between group with one and more NEX of low b-values distribution (all P > 0.05). IVIM parameters in normal WM and GM strongly depended on the choice of the high b-value upper limit. Metrics of IVIM parameters can be affected by low and high b value distribution. Eight low b-values distribution with high b-value upper limit of 800-1000 s/mm may be the relatively proper set when performing brain IVIM studies.