The correlation of perfusion MRI and cerebral angiography in patients with cerebral vascular diseases

Purpose To evaluate the perfusion MR findings in patients with cerebrovascular diseases and to find out the value of perfusion MR in assessing the collateral circulation and the nature of ischemic diseases. Methods Perfusion MRI and cerebral angiography imaging were performed in 16 patients with symptoms of cerebrovascular disease. Dynamic EPI SE T 2 *WI perfusion MR were obtained after a bolus injection of GD DTPA. Qualitative perfusion maps were calculated for regional cerebral blood volume (rCBV) and mean transit time (MTT). Results MTT was sensitive to detect ischemic lesions. All the infarcts showed decreased rCBV, while most of the ischemic lesions showed a normal or increased rCBV. When cerebral collateral circulation was identified on cerebral angiography, most of the lesions were not infarcts. However, the absence of angiographically identifiable cerebral collateral circulation did not always result in an infarct. Most patients with collateral circulation on cerebral angiography had a normal or increased rCBV on perfusion images. In those without angiographically detectable collateral circulation, 50% had decreased rCBV. Despite the absence of angiographic collaterals, the other 50% of patients had normal or increased rCBV. Conclusion A normal or increased rCBV in patients with cerebral ischemic diseases may suggest the presence of collateral circulation. Perfusion image may be a potentially useful adjunctive tool in the prediction of the outcome of ischemic cerebrovascular diseases.