Clinical Application Of CT And MR Angiography And Perfusion Imaging In Intra-and Extracranial Arteries Stenosis

Part I : Comparison of CTA , CE-MRA and DSA in the intra- and extracranial arteries stenosisObjective: To evaluate the accuracy and application of CTA and CE-MRA in the diagnosis of intra- and extracranial arteries stenosis. We investigate the clinical valve of CTA and CE-MRA in the diagnosis of intra- and extracranial artery disease by comparing with DSA .Subjects and methods: 85 of 115 patients with cerebral ischemia disease underwent CTA, 82 of them underwent CE-MRA and 115 of them underwent DSA. 60 patients underwent CTA ,CE-MRA and DSA. After scan,we used substraction way to treat original images .We got images about VR,MIP and MPR.(1) DSA is gold standard. We calculate the sensitivity, specificity of CTA and CE-MRA in diagnosis of cerebral and carotid artery stenosis disease. (2) Each artery is graded by NASCET, we evaluate the correlation of CTA,CE-MRA with DSA (3)60 patients underwent CTA, CE-MRA and DSA. As DSA is gold standard ,we calculate the sensitivity, specificity of CTA and MRA compare the correlation of CTA and CE-MRA.Result: (1) In diagnosis of cerebral and carotid artery stenosis disease,the sensitivity, and specificity of CTA are 93.6% and 99.5%,CE-MRA are 86.7%,99.0%. (2) CTA and CE-MRA were significantly correlated with DSA in evaluate the stenosis grade. Their detection concordance rate is 0.87and 0.75. (3) 60 patient underwent CTA, CE-MRA and DSA. DSA is the gold standard and the concordance rate of CTA and MRA are 0.803. Conclusion: CTA and CE-MRA are significantly correlated with DSA in diagnosing cerebral and carotid artery stenosis. CTA and CE-MRA have a high diagnositic value for intra- and extracranial arteries stenosis.Part II : study of the clinical valve of CT perfusion and PWI in the carotid system stenosisObjective: To investigate the application value of CT perfusion and MR perfusion weighted imaging in patients with carotid system arteries stenosis.To evaluate the relationship between findings of PWI and degree of the cerebral and carotid artery stenosisSubjects and methods: 89 of 94 patients with carotid artery system stenosis diagnosed by CTA ,CE-MRA or DSA were performed CT perfusion examination.35of these 94 patients were performed PWI examination .30 patients were underwent CT perfusion and PWI. The cerebral perfusion parameters of CT perfusion and PWI such as relative cerebral blood flow(rCBF) , relative cerebral blood volume (rCBV) , relative mean transit time (rMTT) and time to peak(TTP) were calculated.(1)Analyze the character of CT perfusion and PWI images of patients with intra- and extracranial arteries stenosis. (2) The relationship between the cerebral perfusion parameters and the degree of stenosis of arteries was analyzed on 89 patients and 35 patients sperate.(3) Comparative evaluate the correlation of CT perfusion and PWI in 30 patients.Result: (1) 69 of 89 patients showed abnomal who underwent CT perfusion.TTP were delay in 69 patients. CBV,CBF are normal and TTP delayed when patients with artery stenosis or occlusion. 30 of 35 patients showed abnomal who underwent PWI. rMTT and TTP were delay in 30 patients.rCBV ,rCBF are normal,rMTT and TTP delay when patients with artery occlusion (2) There was statistically significant correlation between the values of TTP and the degree of artery stenosis in CTP as well as the ratio of the bilateral hemispheres's TTP.There was statistically significant correlation between the values of TTP and rMTT and the degree of artery Stenosis in PWI as well sa the ratio of the bilateral hemispheres's rMTT,TTP.(3) CT perfusion and PWI showed a significant agreement in evaluating cerebral perfusion disorders of ICA and MCA stenosis disease.,the Pearson Correlation of theie TTP rate of the bilateral hemispheres is 0.852.Conclusion: PWI can objectively and clearly demonstrate the abnormal hemo- dynamic changes of brain in patients with unilateral artery stenosis or occlusion. MTT and TTP were sensitive to depict the perfusion damage of brain. However, there is significant correlation between the values of rMTT and TTP and the degree of artery stenosis. Therefore the cerebral hemodynamic change cannot be completely predicted by degree of artery stenosis .CTA or CE-MRA associates with CTP or PWI could not only show the stenosis of the artery but also show the abnormal hemodynamic changes of brain They play an important role in diagnosis , treatment of cerebral ischemia and prevention of cerebral infarct .