3.0T非对比增强MRA诊断下肢动脉病变:与CTA对照

Non-contrast enhanced MRA in diagnosis of lower extremity arterial diseases at 3.0T MR:Compared with CTA

目的探讨采用3.0T MR TRANCE技术的非对比增强MRA(NCE-MRA)诊断下肢动脉狭窄性病变的应用价值。方法对38例下肢动脉病变患者依次行NCE-MRA、CTA和DSA检查。由2名高年资医师采用4分法分别对CTA和NCE-MRA图像质量评分,并对下肢动脉狭窄程度分为4级评价。比较NCE-MRA与CTA图像质量评分,评价CTA和NCE-MRA诊断下肢动脉狭窄的一致性;以DSA结果为金标准,计算CTA和NCE-MRA诊断下肢动脉显著性狭窄的敏感度、特异度和准确率,以配对χ~2检验比较二者间的差异。结果 2名医师对NCE-MRA的质量评分为(3.55±0.30)分和(3.49±0.28)分,略低于CTA[(3.53±0.29)分和(3.45±0.34)分,P均<0.001]。CTA与NCE-MRA诊断下肢动脉狭窄程度的一致性良好,2名医师的Kappa值分别为0.92和0.91(P均<0.05)。CTA与NCE-MRA诊断下肢动脉显著性狭窄的敏感度(医师1:94.77%和94.12%;医师2:94.77%和94.12%)、特异度(医师1:93.86%和91.23%;医师2:92.98%和89.47%)和准确率(医师1:94.38%和92.88%;医师2:94.01%和92.13%)的差异均无统计学意义(P均>0.05)。结论采用TRANCE技术的NCE-MRA可清晰显示下肢动脉狭窄性病变,具有较高的图像质量和诊断准确率,可作为下肢动脉病变、特别是合并肾功能不全及存在对比剂禁忌证患者的安全可靠的替代检查方法。

Objective To explore the value of non-contrast enhanced MRA(NCE-MRA)using TRANCE in diagnosis of lower extremity arterial diseases on 3.0T MR.Methods Totally 38 patients with lower extremity arterial diseases underwent NCE-MRA,CTA and DSA examinations.Imaging quality of CTA and NCE-MRA was evaluated with a 4-point scale,and arterial stenosis was graded using a 4-level scale by 2 experienced doctors.The imaging quality was compared,and the agreement between CTA and NCE-MRA was observed.Taking DSA as the golden standards,the sensitivity,specificity and diagnostic accuracy for significant stenosis of lower extremity arteries of CTA and NCE-MRA were calculated and compared.Results The overall imaging quality of NCE-MRA(3.55±0.30 and 3.49±0.28)was lower than those of CTA(3.53±0.29 and 3.45±0.34,both P<0.001)by 2 doctors.Inter-modality agreement between CTA and NCE-MRA was excellent for assessment of stenosis(Kappa=0.92 and 0.91,both P<0.05).There was no statistical difference in sensitivity(doctor 1:94.77%and 94.12%,doctor 2:94.77%and 94.12%),specificity(doctor 1:93.86%and 91.23%,doctor 2:92.98%and 89.47%)nor accuracy(doctor 1:94.38%and 92.88%,doctor 2:94.01%and 92.13%)for significant stenosis of lower extremity arteries between CTA and NCE-MRA(all P>0.05).Conclusion NCE-MRA using TRANCE on 3.0T MR can clearly display lower extremity arterial stenosis with excellent imaging quality and high diagnostic accuracy,which can be used as a safe and reliable alternative method for patients with renal insufficiency or contraindication of contrast agents.