Measurement of cerebral perfusion with dual-echo multi-slice quantitative dynamic susceptibility contrast MRI

Quantitative cerebral perfusion was measured in vivo using dynamic suscepti bility contrast magnetic resonance imaging. A dual-echo acquisition was use d to eliminate T-1-enhancement. The arterial input curve was measured in a separate slice in the neck to minimize partial volume effects, Data analysi s was performed using a maximum likelihood expectation maximization method to be less sensitive to noise or contrast arrival time differences. From th e contrast response curves obtained, the cerebral blood volume (CBV) and no w (CBF) and the timing parameters mean transit time (MTT), time of appearan ce (TA), and time-to-bolus peak (TBP) were obtained, Adjacent slices were m easured to permit discrimination between intra-and inter-subject variance. The group investigated consisted of 41 subjects without cerebral pathology on anatomical MRI, Perfusion parameters for gray (GM) and white matter (WM) were obtained: CBV (GM) = 6.78 +/- 0.99 ml/100 mi, CBV(WM) = 3.78 +/- 0.96 ml/100 mi, CBF (GM) = 68.7 +/- 21.2 ml/100 ml/min, CBF (WM) = 35.8 +/- 12. 7 ml/100 ml/min, and average GM/WM ratio for CBV (GM/WM) = 1.87 +/-: 0.42 a nd CBF (GM/WM) = 1.99 +/- 0.48, Measured temporal aspects of perfusion were : mean transit time (MTT) (GM) = 6.4 +/- 1.8 seconds. MTT (WM) = 6.9 +/- 2. 3 seconds, time of appearance (TA) (GM) = 1.4 +/- 0.9 seconds, TA(WM) = 2.0 +/- 1.0 seconds, and time-to-bolus peak (TBP) (GM) = 2.4 +/- 1.4 seconds, TBP (WM) = 3.0 +/- 1.5 seconds. The average values were in agreement with t hose from the literature. Inter- and intra-person variances were estimated using an ANOVA test, and the sources of variance in the parameters, such as image noise, biological variability, and measurement errors of the arteria l input curve were found to be of the same order of magnitude, (C) 1999 Wil ey-Liss, Inc.