Correlation of regional cerebral blood flow measured by stable xenon CT and perfusion MRI

Purpose: The purpose of this work was to investigate the validity of perfusion MRI in comparison with stable xenon CT for evaluating regional cerebral blood flow (rCBF). Method: The rCBF was measured by xenon CT and perfusion MRI within a 24 h interval in 10 patients (mean +/- SD age 63 +/- 10 years). For perfusion MRI, absolute values of rCBF were calculated based on the indicator dilution theory after injection of 0.1 mmol/kg of Gd-DTPA. Eight to 10 regions of interest (37 mm(2)) were located in the white and gray matter on the rCBF images for each of the 10 patients. Results: The mean +/- SD values of rCBF in gray matter were 48.5 +/- 14.1 ml/100 g/min measured by xenon CT and 52.2 +/- 16.4 ml/100 g/min measured by perfusion MRI. In the white matter, the rCBF was 22.6 +/- 9.1 ml/100 g/min by xenon CT and 27.4 +/- 6.8 ml/100 g/min by perfusion MRI. There was a good correlation of rCBF values between perfusion MRI and xenon CT (Pearson correlation coefficient 0.83; p < 0.0001). Conclusion: Comparable to xenon CT, perfusion MRI provides relatively high resolution, quantitative local rCBF information coupled to MR anatomy.