磁共振血管造影与数字减影血管造影在脑血管狭窄闭塞性疾病诊断中的比较研究

目的：对比研究磁共振血管造影（MRA）（1．5、3．0T）与数字减影血管造影（DSA）对于脑血管狭窄闭塞性疾病诊断及量化的作用。方法：回顾性研究110例临床怀疑惠有脑血管病变的受试病人，其中55例行1．5TMRA扫描（3DTOF序列），另55例行3．OTMRA（3DTOF序列）扫描。在最大密度投影重建像及常规DSA图像下测定脑血管狭窄程度，以北美有症状颈动脉内膜切除试验标准为参考。结果：对于脑血管狭窄的分级，1．5T、3．OTMRA与DSA结果一致率分别为86．5％、90．5％。在诊断明确后，1．5TMRA敏感度及特异度分别为90％、98％；阳性预测值（PPV）及阴性预测值（NPV）分别为87％、99％；总准确率为94％。同时，3．0TMRA敏感度及特异度分别为92％、99％，PPV及NPV分别为91％、99％，准确率为96％。对于脑血管狭窄闭塞疾病的测定，DSA与1．5TMRA（P=0．31）、3．0TMRA（P=0．30）差异均无统计学意义，1．5TMRA与3．0TMRA之间差异亦无统计学意义（P=0．70）。结论：本实验结果表明，对于脑血管狭窄闭塞性疾病的诊断MRA的3DTOF序列能够作为DSA之外的一种可靠的诊断方法，且3．0TMRA稍优于1．5TMRA．

Comparison of MR angiography and digital subtraction angiography for detecting of cerebrovascular stenosed and occlusive disease

Objective： To evaluate the ability of 1.5 T MRA and 3.0 T MRA separately to help detect and quantify eerebrovascular stenoses and occlusion compared with digital subtraction angiography （DSA）. Methods： This retrospective study enrolled total of 110 patients suspected for cerebrovascular lesions. Fifty-five patients underwent 3 D time- of- flight （TOF） MRA at 1.5 T and the remaining 55 patients underwent 3 D TOF MRA at 3.0 T MRA. The guidelines of the North American Symptomatic Carotid Endarterectomy Trial for measuring stenosis were applied on maximum intensity projections images and conventional digital subtraction angiography. Results： Grading of stenoses on 3 D TOF MRA agreed with grading of stenoses on DSA images in 86.5% of arteries on 1.5 T MRA and 90. 5 % of arteries on 3.0 T MRA. After consensus interpretation 1.5 T MRA had sensitivity of 90% and specificity of 98%. Positive predictive value （PPV） and negative predictive value （NPV） were 87% and 99% respectively. Overall accuracy was 94%. Similarly,3.0 T MRA had a sensitivity of 92% , specificity of 99% , PPV of 91% and NPV of 99%. Overall accuracy was 96%. There was no significant difference found in the measurement of stenosis and occlusion between DSA and 1.5 T MRA （P = 0.31 ）, DSA and 3.0 T MRA （P = 0.30）. Similarly, no significant difference was found between 1.5 T MRA and 3.0 T MRA （ P = 0. 70 ）. Conclusion： This study provides additional evidence that 3 D TOF MRA could become a diagnostic alternative to DSA in the management of patients with cerebrovascular. 3.0 T MRA shows slightly better results than 1.5 T MRA.