Method for improving the accuracy of quantitative cerebral perfusion imaging

Purpose: To improve the accuracy of dynamic susceptibility contrast (DSC) measurements of cerebral blood flow (CBF) and volume (CBV). Materials and Methods: In eight volunteers, steady-state CBV (CBV_SS) was measured using TrueFISP readout of inversion recovery (IR) before and after injection of a bolus of contrast. A standard DSC (STD) perfusion measurement was performed by echo-planar imaging (EPI) during passage of the bolus and subsequently used to calculate the CBF (CBF_DSC) and CBV (CBV_DSC). The ratio of CBV_SS to CBV_DSC was used to calibrate measurements of CBV and CBF on a subject-by-subject basis. Results: Agreement of values of CBV (1.77 ± 0.27 mL/100 g in white matter (WM), 3.65 ± 1.04 mL/100 g in gray matter (GM)), and CBF (23.6 ± 2.4 mL/(100 g min) in WM, 57.3 ± 18.2 mL/(100 g min) in GM) with published gold-standard values shows improvement after calibration. An F-test comparison of the coefficients of variation of the CBV and CBF showed a significant reduction, with calibration, of the variability of CBV in WM (P < 0.001) and GM (P < 0.03), and of CBF in WM (P < 0.0001). Conclusion: The addition of a CBV_SS measurement to an STD measurement of cerebral perfusion improves the accuracy of CBV and CBF measurements. The method may prove useful for assessing patients suffering from acute stroke.