非增强MRA诊断下肢动脉病变的应用研究

目的：探讨QISS非增强MRA技术诊断下肢动脉闭塞性病变的临床应用价值。方法：51例下肢动脉病变患者行双下肢QISS-MRA和CE-MRA扫描，评价两种检查方法的图像质量，并以CE—MRA为参照标准，计算QISSMRA诊断下肢动脉显著性狭窄（≥50％）的敏感度、特异度、阳性预测值、阴性预测值和诊断准确性，并以配对χ2检验分析两种检查方法对诊断下肢动脉显著性狭窄（≥50％）的差异有无统计学意义，两种检查方法的相关性采用kappa检验。结果：51例中48例成功行QISS-MRA检查，其中图像质量优、良、差者分别为40（78．43％）、8（15．69％）和3例（5．88％）。按血管节段计算，QISS-MRA诊断下肢动脉显著性狭窄的敏感度和特异度分别为90．15％和98．87％，阳性预测值和阴性预测值分别为96．75％和96．42％，总体符合率为95．91％。对于下肢动脉显著性狭窄的诊断，QISS-MRA与CE-MRA的差异无统计学意义（χ2=3．76，P〉0．05），且两种检查方法具有极好的相关性（r值为0．950，P〈0．001）。结论：QISS-MRA检查成功率较高、图像质量良好并且诊断效果接近CE—MRA，对诊断下肢动脉闭塞性病变有一定的临床应用潜力。

Evaluation of non-contrast-enhanced MR angiography in patients with lower extremity peripheral arterial disease

Objective：To evaluate the value of non-contrast-enhanced MR angiography using quiescent-interval single- shot （QISS） technique in the diagnosis of lower extremity peripheral arterial disease. Methods： Fifty-one patients with pe- ripheral arterial disease in lower extremity underwent QISS-MRA and contrast-enhanced MRA （CE-MRA） examinations. Imaging quality and diagnostic accuracy of QISS-MRA for detecting significant artery stenosis （≥50% or occlusion） were assessed using CE-MRA as a standard reference. Paired χ2 test was used to analyze the difference of diagnostic accuracy be- tween CE MRA and QISS-MRA. Cohen＇s kappa was used to assess agreement between the two methods in the diagnosis of significant artery stenosis. Results.. Forty-eight patients had successfully undergone QISS-MRA and 486 arterial segments had diagnosable image quality. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of QISS-MRA for detecting significant stenosis were 90. 15 %, 98.87 %, 96. 75 %, 96.42 % and 95. 91 %, respectively. There was no significant difference between the two methods （χ2 ： 3.76,P〉0.05）. The interacter reliability of the two methods was very good （r value=0. 950 ,P〈0. 001）. Conclusion： High success rate and reliable image quality were demonstrated by QISS-MRA. It had equivalent diagnostic accuracy for detecting significant artery stenosis in comparison with CE-MRA and may be a potential clinical technique for the evaluation of lower-extremity arterial disease.