The Application Value Of CTP And CTA Of The Unilateral ICA And MCA Lesions In Patients With Chronic Cerebral Ischemia

Part 1 Evaluation of chronic brain ischemia associated with stenosis of unilateral ICA and MCA with combined CTA and CTP:an initial studyObjective: To explore the feasibility of combination of CTA and CTP for evaluation of chronic brain ischemia. And in the condition of intact anterior circulation,we assess the difference of the perfusion parameters of the MCA territory in the same or different stenosis of unilateral internal carotid artery(ICA) and middle cerebral artery(MCA).Methods: 114 patients with chronic brain ischemia were examined with CT and MRI. 7 cases with hemorrhage and 5 cases with severe cerebral infarction were excluded. Then 102 cases had the combined examination of CTA and CTP. Finally 73 patients were included in this study after excluding another 29 cases for the reason of poor images. All imaging data were reviewed blindly by two neuroradiologists.Statistical analysis were made for the perfusion of MCA territory between same and various stenosis of unilateral ICA and MCA.Results: Only four cases (4%, 4/102) were excluded because their poor imaging. In the 73 patients with patent anterior circulation and without other vascular diseses, mild and medium stenosis, severe stenosis,and occlusion of unilateral initial ICA and M1-2 segment of MCA were 10 and 8 cases,12 and 13 cases,12 and 18 vases separately. There was no difference of ipsilateral MCA territory between severe stenosis and occlusion of initial ICA and M1-2 segment of MCA(P>0.05). Except for rPS,significant difference was detected for othe CTP paramaters between mild/medium stenosis and severe stenosis/occlusion of both initial ICA and M1-2 segment of MCA(P<0.05). When the degree of stenosis of above mentioned arteries was same,no obvious difference of perfusion of MCA territory was found between the cases of stenosis of initial ICA and M1-2 segment of MCA(P>0.05).Conclusion: It is feasibility to perform the combined examination of CTA and CTP for chronic brain ischemia cases. When the anterior circulation was intact, there was prominent difference of the perfusion of ipsilateral MCA territory between the cases of mild/medium stenosis and severe stenosis/occlusion for both initial ICA and M1-2 segment of MCA. Whereas there was no difference of perfusion between severe stenosis and occlusion for both arteries. And no obvious difference was detected neither when the degree of stenosis of initial ICA and M1-2 segment of MCA was same.Part 2 Brain perfusion types of various stenosis of initial segment of unilateral ICA:Evaluation with the combination of CTA and CTPObjective: To evaluate the correlation between different stenosis of initial segment of unilateral ICA and perfusion types of MCA territory in the condition of intact anterior circulation. And to investigate the diversity of perfusion type with different stenosis of unilateral ICA.Methods: 114 patients with chronic cerebral ischemia were examined with CT and MRI. 7 cases with hemorrhage and 5 cases with severe cerebral infarction were excluded. Then 102 cases had the combined examination of CTA and CTP. Finally 34 patients were included in this study after excluding another 68 cases for various other reasons. All imaging data were reviewed blindly by two neuroradiologists. Statistical analysis were made for the relationship of stenosis of unilateral ICA and perfusion type.Results: Mild and medium stenosis, severe stenosis and occlusion of unilateral ICA were 10 cases (30%), 12 cases (35%), 12 cases (35%) for the 34 cases. The perfusion types I,II and III of MCA territory of 10 cases with mild-to-moderate stenosis of unilateral ICA were 0 cases(0%), 4 cases(40%)and 6 cases(60%)separately. The perfusion types I,II and III of MCA territory of 12 cases with severe stenosis of unilateral ICA were 4 cases(33%,8 cases(67%)and 0 cases(0%) separately. The perfusion types I,II and III of MCA territory of 12 cases with occlusion of unilateral ICA were 8 cases(67%),4 cases(33%)and 0 cases respectively. The relationship between different stenosis of initial segment of ICA and MCA territory perfusion type was positive correlation(r=0.333;r=0.089). Significant differences was found of the corresponding MCA territory perfusion types between mild-to-moderate and severe stenosis,occlusion of initial ICA stenosis (x2=11.244, x2=13.933,P<0.05). Whereas there was no obvious difference for perfusion types between severe stenosis and occlusion of initial ICA stenosis(x2=2.667,P>0.05). The cerebral perfusion abnormality with severe stenosis/occlusion of ICA was significantly more priminent than that of mild-to-moderate stenosis (x2=17.486,P<0.05).Conclusion: When the anterior circulation complete, the relationship between different stenosis of ICA start and cerebral perfusion type was moderate correlative; stenosis degree of simple unilateral ICA start and clinical type were no obvious differences; the abnormal perfusion caused by severe stenosis/occlusion was significantly higher than mild-to -moderate stenosis,and the perfusion types between the severe stenosis and occlusion was no obvious difference.