Optimized Combination of b-values for IVIM Perfusion Imaging in Acute Ischemic Stroke Patients. Clinical neuroradiology Zhu, G., Heit, J. J., Martin, B. W., Marcellus, D. G., Federau, C., Wintermark, M. 2019


PURPOSE: To determine the optimal combination of low b-values to generate perfusion information from intravoxel incoherent motion (IVIM) in patients with acute ischemic stroke (AIS) considering the time constraints for these patients.METHODS: A retrospective cohort study of AIS patients with IVIM MRI was performed. A two-step voxel-by-voxel postprocessing was used to derive IVIM perfusion fraction maps with different combinations of bvalues. Signal values within regions of ischemic core, non-infarcted ischemic hemisphere, and contralateral hemisphere were measured on IVIM (f, D*, fD*, D) parameter maps. Bland-Altman analysis and the Dice similarity coefficient were used to determine quantitative and spatial agreements between the reference standard IVIM (IVIM with 6 bvalues of 0, 50, 100, 150, 200, 1000?s/mm2) and other combinations of bvalues. Significance level was set at p?<0.05.RESULTS: There were 58 patients (36males, 61.3%; mean age 70.2?±13.4 years) included. Considering all IVIM parameters, the combination of bvalues of 0, 50, 200, 1000 was the most consistent with our reference standard on Bland-Altman analysis. The best voxel-based overlaps of ischemic regions were on IVIMD, while there were good voxel-based overlaps on IVIMf.CONCLUSION: The IVIM with these four bvalues collects diffusion and perfusion information from asingle short MRI sequence, which may have important implications for the imaging of AIS patients.

View details for DOI 10.1007/s00062-019-00817-w

View details for PubMedID 31375894