Whole brain quantitative CBF, CBV, and MTT measurements using MRI bolus tracking: Implementation and application to data acquired from hyperacute stroke patients

A robust whole brain magnetic resonance (MR) bolus tracking technique based on Indicator dilution theory, which could quantitatively calculate cerebra l blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT ) on a regional basis, was developed and tested. T2*-weighted gradient-echo echoplanar imaging (BPI) volumes were acquired on 40 hyperacute stroke pat ients after gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) bolus injection. The thalamus, white matter (WM), infarcted area, penumbra, and mirror Infarcted and penumbra regions were analyzed. The calculation of the arterial input function (AIF) needed for absolute quantification of CBF, C BV, and MTT was shown to be user independent. The CBF values (ml/min/100 g units) and CBV values (% units, In parentheses) for the thalamus, WM, infar ct, mirror Infarct, penumbra, and mirror penumbra (averaged over all patien ts) were 69.8 +/- 22.2 (9.0 +/- 3.0 SD): 28.1 +/- 6.9 (3.9 +/- 1.2); 34.4 /- 22.4 (7.1 +/- 2.7); 60.3 +/- 20.7 (8.2 +/- 2.3); 50.2 +/- 17.5 (10.4 +/- 2.4); and 64.2 +/- 17.0 (9.5 +/- 2.3). respectively, and the corresponding MTT values (in seconds) were 8.0 +/- 2.1; 8.6 +/- 3.0; 16.1 +/- 8.9; 8.6 /- 2.9; 13.3 +/- 3.5; and 9.4 +/- 3.2. The infarct and penumbra CBV values were not significantly different from their corresponding mirror values, wh ereas the CBF and MTT values were (P < 0.01). Quantitative measurements of CBF, CBV, and MTT were calculated on a regional basis on data acquired from hyperacute stroke patients, and the CBF and MTT values showed greater sens itivity to areas with perfusion defects than the CBV values. (C) 2000 Wiley -Liss, Inc.