3T磁共振增强全心冠状动脉成像技术临床应用价值

Clinical application and value of 3 Tesla contrast enhanced whole-heart coronary magnetic resonance angiography

目的 探讨自由呼吸导航门控3 T磁共振增强全心冠状动脉三维成像技术临床应用可行性及其价值.方法应用自由呼吸导航3 T磁共振增强全心冠状动脉三维成像方法对临床疑似冠心病患者行全心冠状动脉成像,增强采用钆贝葡胺注射液（0.2 mmol/kg）静脉缓慢注射,流率0.3ml/s.数据经后处理获得冠状动脉主要分支图像,评价图像质量,并以选择性冠状动脉造影检查结果为参照标准,采用9段划分法评价冠状动脉主要分支的有意义狭窄（＞50%）,判断磁共振增强冠状动脉成像对冠心病的诊断准确性及其价值.结果26例病例中23例顺利完成磁共振检查,平均扫描时间为（10.4±2.1）min.选择性冠状动脉造影显示的202个节段中,磁共振增强冠状动脉成像显示可评价节段178个（88.1%）,以近、中段图像质量较好.与选择性冠状动脉造影比较,磁共振增强冠状动脉成像在显示近段及中段可评价节段上差异无统计学意义（P＞0.05）.磁共振冠状动脉成像显示阳性9例,阴性14例.选择性冠状动脉造影显示11例阳性,12例阴性.磁共振冠状动脉成像有意义的狭窄总体诊断符合率91.3%（21/23）,灵敏度81.8%（9/11）,特异度88.5%（169/191）,阴性预测值98.8%（9/31）.结论自由呼吸导航门控3 T磁共振增强全心冠状动脉三维成像技术能够对冠状动脉近中段有意义的狭窄进行初步评估,一致性较好.但对冠状动脉远段及小分支狭窄的评估有一定限度.

Objective To investigate the clinical application, feasibility and value of 3 T wholeheart contrast enhanced free-breathing navigator-gated three-dimensional coronary magnetic resonance angiography （CE-CMRA）. Methods 3 T CE-CMRA was used to examine patients with suspected coronary heart disease （CAD）. Gd-BOPTA（0. 2 mmol/kg） was injected intravenously with slow infusion rate（0. 3ml/s） to perform enhancement. Data were post-processed to obtain principal branches of coronary artery and picture quality was evaluated. According to results of selective coronary arteriography （ SCAG ）, the diagnostic accuracy of CE-CMRA for diagnosing CAD was judged by means of detecting significant stenosis （ 〉50% ） of the principal branches based on the 9 segments of coronary artery. Results Twenty-three out of 26 patients successfully completed the examination. The mean scanning time was （ 10. 4 ± 2. 1 ） minutes,178 out of 202 （88. 1% ） SCAG demonstrated segments could be evaluated by CE-CMRA. The imaging quality was superior in proximal and middle segments of coronary artery principal branches than in distal segments. Based on patient-level, there were 9 positive cases and 14 negative cases examined by CE-CMRA compared with 11 positive cases and 12 negative cases examined by SCAG, respectively. The whole diagnose accordance rate of CE-CMRA was 91.3% （21/23）compared with SCAG. The sensitivity, specificity and negative predictive values were 81.8% （9/11）, 88.5% （169/191） and 98.8% （9/31）respectively. Conclusions 3 T CE-CMRA is a feasible non-invasive imaging modality for diagnosing CAD,especially to detect significant stenosis in proximal and middle segments of coronary artery principal branches. However, the detecting efficacy is limited in assessing stenosis of distal segment and small branches of coronary artery.