磁共振黑血序列冠状动脉管壁成像评价粥样硬化斑块初步研究结果:与血管内超声对照研究

Accuracy of MR imaging to identify the coronary artery plaque:comparison with intravascular ultrasound

目的与血管内超声(IVUS)对照,探讨磁共振黑血序列冠状动脉管壁成像评价冠状动脉斑块的可行性及准确性。方法拟行IVUS检查及行IVUS检查而未行支架植入术的患者11例,分别于IVUS术前及术后10日内行磁共振检查。成像序列采用二维横截面、双反转恢复、呼吸导航心电门控触发、压脂TSE序列,采集自病变冠脉开口至中段无间隔连续扫描,测量以下数据:血管横截面积(CSA)、管腔CSA、斑块负荷、管壁信噪比(SNR)及对比噪声比(CNR)。在IVUS上将靶冠脉自开口分为每5mm节段,与MRI管壁横截面一一对应。当冠状动脉管壁厚度≥0.5mm时考虑存在斑块。结果共9例病人,9支冠脉,37个层面纳入分析;2例病人被排除(因扫描时间长,病人无法坚持),扫描成功率82%。37个层面中有20个有斑块。斑块层面的斑块负荷、SNR、CNR大于非斑块层面(分别为0.70±0.11vs0.58±0.14,1.95±0.39vs1.48±0.21,5.47±2.06vs2.99±0.78,P<0.05)。MRI斑块层面血管CSA、管腔CSA及斑块负荷与IVUS比较,具有良好的相关性(13.66±4.52vs14.92±6.37,4.62±2.23vs6.03±3.85,0.63±0.13vs0.60±0.14,P<0.05)。结论冠状动脉黑血管壁成像可以发现冠状动脉近中段的粥样硬化斑块,且能够相对评价狭窄段血管面积和管腔面积。

Objective： To evaluate the ability of black blood coronary arterial wall MR imaging to identify the coronary artery plaque, using intravascular ultrasound （IVUS） as the golden standard. Materials and Methods： Eleven patients （mean age 61.8±9.7 years, 6 men and 5 women） who plan to do IVUS or had done IVUS examinations, but had not done percutaneous coronary intervention （PCI）, underwent black-blood coronary wall MR imaging within 10 days before or after PCI respectively. All scans were performed on a 1.5T MR scanner. Cross-sectional coronary wall imaging was acquired using a 2D double-inversion-recovery, ECG-triggered, navigator-gated, fatsuppressed, Turbo-Spin-Echo （TSE） sequence on the lesion of coronary artery from the osfium to the middle segment continuously without gap. The vessel cross-sectional area （CSA）, luminal CSA, maximal wall thickness, plaque burden, CNR [（SIvessel wan - SIperivascular area） / SDnoise） and SNR （SIvessel wall / SDnoise） were measured in each slice which were then compared with the IVUS images. IVUS were divided into 5 mm segments to compare side by side with MRI. Results： Nine coronary arteries and 37 slices from 9 patients were imaged and analyzed by both MRI and IVUS. Two patients were ruled out due to long examination time. Twenty of 37 slices were found plaques on both IVUS and MRI; the plaque burden, SNR, CNR in the coronary wall containing plaque were greater compared to the normal coronary wall （0.70±0.11 vs 0.58±0.14, 1.95±0.39 vs 1.48±0.21, 5.47±2.06 vs 2.99±0.78, respectively, P〈0.05）. There were good correlation between MRI and IVUS in vessel CSA, lumen CSA, and plaque burden.（13.66±4.52 vs 14.92±6.37, 4.62±2.23 vs 6.03±3.85, 0.63±0.13 vs 0.60±0.14, respectively, P〈0.05）. Conclusion： Coronary wall MRI can identify coronary plaque in proximal segments.