Heterogeneity and Reproducibility of Cerebral Perfusion and Capillary Volume Fraction Measurements, Derived from Combined Arterial Spin Labelling and Intravoxel Incoherent Motion Imaging of the Healthy Adult Brain

Patrick W. Hales¹, Chris A. Clark¹

Multi-TI ASL and multi-b-value DWI measurements were made in ten healthy adult brains, and repeated after 20 min in five subjects. Estimates of capillary volume fraction (vbw) were derived from the DWI data using the IVIM model. vbw data were used in a two-compartment ASL model to estimate cerebral blood flow (CBF), bolus arrival time (BAT) and capillary permeability surface product (PS). CBF was most heterogeneous in the frontal lobe, vbw was most heterogeneous in the occipital lobe. By incorporating measured vbw values in a two-compartment ASL models, PS measurements showed improved heterogeneity and repeatability compared to previously published studies.