Brain magnetic resonance perfusion-weighted imaging in patients with unilateral middle cerebral artery stenosis

Objective To evaluate the manifestation of the cerebral ischemia caused by stenosis or occlusion of middle cerebrala rtery(MCA)on magnetic resonace(MR)perfusion-weighted imaging(PWI).Methods MR PWI were performed in 31 patients withu nilateral stenosis or occlusion of MCA diagnosed by DSA.The cerebral perfusion parameters including regional cerebral blood volume( rCBV),regional cerebral blood flow(rCBF),regional mean transit time(rMTT)and regional time to peak(rTTP)of the both the cerebralh emispheres were analyzed in all the patients.Results Among 31 patients with unilateral MCA stenosis or occlusion diagnosed by DSA,a bnormal perfusion of the involved cerebral hemispheres was found in 11 of the 14 patients with MCA mild or moderate stenosis and in 17p atients with MCA severe stenosis or occlusion.The rCBV,rCBF and rMTT of the involved cerebral hemispheres were insignificantlyd ifferent from those of the other cerebral hemispheres(P0.05),and rTTP of the involved cerebral hemispheres significantly increasedc ompared with the other hemispheres in the patients with MCA mild or moderate stenosis(P0.01).In patients with MCA severe stenosiso r occlusion,rCBF was significantly reduced(P0.05),rMTT and rTTP were significantly increased(P0.05)in the involved cerebralh emispheres compared with those in the other cerebral hemispheres,and there was insignificant difference in rCBV between both thec erebral hemispheres(P0.05).Conclusions It is suggested that the severity of unilateral MCA stenosis and status of blood supply for thec erebral tissues may be exactly assessed by MR PWI,which is helpful to clinical diagnosis in the patients with unilateral MCA stenosis.