Study of MR Perfusion-weighted Imaging in Patients with Chronic MCA Stenosis or Occlusion

Objective:To investigate the diagnostic value of MR perfusion-weighted imaging (PWI) in patients with severe unilateral middle cerebral artery (MCA) chronic stenosis or occlusion.Methods:PWI was performed in 28 patients with severe unilateral MCA stenosis or occlusion.The cerebral perfusion parameters included rCBF,rCBV,rMTT and TTP of the occluded as well as the contralateral hemisphere.These values were calculated,and the qualitative as well as quantitative analysis were carried out.Results:Of the 28 patients with severe MCA stenosis or occlusion,the rCBV,rMTT and TTP values showed statistically significant difference (P0.01) of abnormal regions between the occluded and the contralateral hemisphere.However,the rCBF values showed no statistically significant difference (P0.05).The rMTT and TTP were significantly delayed on the occluded side.In 24 cases,only the MCA supplied territory were involved;in 4 cases the MCA supplied territory as well as the border zone were involved.Conclusion:The abnormal cerebral hemodynamic changes in patients with unilateral severe MCA stenosis or occlusion can be demonstrated by PWI.