全心冠状动脉MR成像的图像质量及其影响因素

Image quality and impact factors of whole-heart coronary MR angiography

目的评价全心冠状动脉MR成像(WH CMRA)的图像质量及其影响因素。方法对88例疑诊冠心病者,采用1.5T非对比增强、心电门控兼呼吸导航、T2预备脉冲并脂肪抑制的3D稳态自由进动序列扫描;采用4分制(1分,差;4分,优)评价图像质量,对得分2～4分者评估冠状动脉的狭窄程度,以CAG显示狭窄≥50%为标准评价MR的准确率。结果①完成组:79例(79/88,89.77%)完成WH CMRA检查,扫描时间(13.28±4.33)min,心率(67±8)次/分,呼吸导航效率(34.12±8.10)%,体质量指数(BMI)为(25.90±3.20)kg/m2;75例平均图像质量评分(2.9±1.0)分,4例图像质量为1分;②对照组:42例(42/75,56.00%)完成CAG检查,扫描时间(13.50±4.60)min,心率(67±10)次/分,图像质量评分(3.2±0.9)分,与CAG间隔(5±2)天;WH CMRA诊断冠状动脉狭窄的敏感度、特异度、阳性预测值、阴性预测值和准确率分别为90.48%(19/21)、66.67%(14/21)、73.08%(19/26)、87.50%(14/16)和78.57%(33/42);③完成组与对照组间平均年龄、心率、扫描时间、呼吸导航效率、BMI和图像质量间差异均无统计学意义(P均>0.05)。结论WHCMRA图像质量大多能满足诊断需要,主要影响因素包括心脏搏动、呼吸运动和BMI。

bjective To observe the image quality and impact factors of whole-heart coronary magnetic resonance angiography （WH CMRA）. Methods Eighty-eight patients underwent WH CMRA without contrast material at 1.5T MR using 3D ECG-triggered, navigator-gated, fat-suppressed, T2-prepared steady state free precession sequence. Image quality of WH CMRA was evaluated using 4-point scale （1, poor; 4, excellent）. Segments which scored of 1 were excluded from further analysis. The diagnostic performance of WH CMRA in detecting stenosis was compared with that of conventional CAG as stenosis ≥50%. Results ①Totally 79 patients （79/88, 89.77%） successfully completed examination in （13.28±4.33）min, their heart rate was （67±8）bpm, navigator accept rate was （34.12±8.10）%, body mass index （BMI） was （25.90±3.20）kg/m2. Qualitative image analysis was performed on 79 patients. Except 4 patients scored as 1, the average score for other 75 patients was 2.9±1.0. ②Conventional CAG was completed in 42 patients （42/75, 56.00%） in （13.50±4.60）min, and their heart rate was （67±10）bpm and image quality was 3.2±0.9. The time interval of WH CMRA and CAG was （5±2） days. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of WH CMRA for detecting coronary stenosis based on patient was 90.48% （19/21）, 66.67% （14/21）, 73.08% （19/26）, 87.50% （14/16） and 78.57% （33/42）, respectively. ③No significant difference of mean age, heart rate, scan time, navigator accept rate, BMI nor image quality was found between patients completed WH CMRA and CAG （all P〉0.05）. Conclusion The image quality of WH CMRA can satisfy diagnosis of coronary stenosis, which relates to heart rate, breathe pattern and BMI.