Application of MR angiography and perfusion weighted imaging in the evaluation of abnormal vessels in Moyamoya disease, cerebral revascularization after operation and cerebral hemodynamics during the perioperative period / 中华放射学杂志

ABSTRACT

Objective To evaluate the clinical value of MRA on the abnormal vessels in Moyamoya and cerebral revascularization , and to evaluate PWI in the observation of cerebral hemodynamics before and after cerebral revascularization.Methods Twenty-four patients with Moyamoya disease ascertained by DSA received cerebral revascularization on one side.MRA and PWI were performed for all patients before and after the operation , while DSA was performed after operation in nine patients to compare the images of MRA and DSA by three experienced radiologists.Perfusion parameters in terminal branches of middle cerebral artery ( MCA) on the operative side were compared with those on the contralateral sides and the cerebellum , including cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and delay time ( DT) , as well as relative ratio ( values on the operative side/values on the contralateral side , and values on the operative side/values on the cerebellar region ) of perfusion parameters (rCBF, rCBV, rMTT and rDT) were calculated.Comparisons of the data between different groups were performed using paired Student′s t test.Results MRA was similar to DSA in displaying the internal carotid artery , main branches stenosis, Moyamoya vessels, and cerebral revascularization.DSA was better in displaying collateral vessels than MRA, but primary images of MRA provided anatomic and pathologic information of cerebral parenchyma.After the operations , rCBF (1.30 ±0.27) and rCBV (1.26 ±0.21) of MCA perfusion regions on the operative and the contralateral sides were higher than rCBF (0.73 ±0.15) and rCBV (0.98 ±0.12) before the operation significantly (t=-7.19,-6.64,P<0.05).rMTT (1.06 ±0.20) and rDT (1.07 ± 0.18) after the operation were lower than rMTT(1.53 ±0.34)and rDT (1.40 ±0.26) before the operation (t=5.62,5.40,P<0.05) .In MCA perfusion regions on the operative and cerebellar sides , rCBF(1.93 ± 0.34)and rCBV(2.25 ±0.35)were higher than rCBF(0.88 ±0.18)and rCBV(1.16 ±0.22)(t=-3.04,-3.06,P<0.05) before the operation.rMTT (1.13 ±0.29) and rDT (1.29 ±0.12) were lower than rMTT (1.88 ±0.19 ) and rDT ( 3.29 ±0.47 ) before the operation ( t =4.01, 4.72, P <0.05 ).Conclusions MRA is a safe , reliable method to evaluate abnormal vessels and cerebral revascularization after the operation in moyamoya disease.PWI can detect poor cerebral perfusion , and can be used for assessment of the effect of cerebral revascularization.