三维单次扫描多组织对比序列和磁化强度预备梯度回波序列诊断颈动脉斑块内出血的对比研究

Carotid intraplaque hemorrhage imaging using MRI： comparison of the diagnostic performance between multi-contrast atherosclerosis characterization and magnetization-prepared rapid acquisition gradient-echo with histology

目的以组织病理学为诊断金标准，评价3D单次扫描多组织对比序列（MATCH）与3D磁化强度预备梯度回波序列（MPRAGE）对颈动脉斑块内出血（IPH）的诊断效能。方法2014至2015年搜集经超声检查诊断为颈动脉狭窄〉50%且拟行颈动脉内膜剥脱术患者30例，术前分别行MATCH、MPRAGE及3D时间飞跃法（TOF）序列扫描，扫描范围以颈动脉分叉为中心覆盖全部斑块。所采集的影像数据用MRI-Plaque View半自动软件对易损斑块的IPH进行分析，采用Kappa检验分析MATCH与MPRAGE序列及两个序列与病理比较的一致性；与病理相比较，计算两个序列的敏感度、特异度。对两个序列的ROI进行信噪比（SNR）、对比信噪比（CNR）及对比比率（CR）的计算，采用Wilcoxon秩和检验比较两个序列的SNR、CNR、CR的统计学差异。结果30例患者最终602个影像层面及相对应的95层病理图结果进行分析，MATCH和MPRAGE序列对斑块内出血的检出有很好的一致性（Kappa=0.773，P〈0.05）；以95层相对应层面病理作为金标准，MATCH和MPRAGE序列分别与病理进行一致性分析，同样得到很好的一致性（Kappa值分别为0.778和0.685，P〈0.05）；MATCH序列对于IPH诊断的敏感度和特异度为93.2%（68/73）和90.9%（20/22）；MPRAGE序列诊断IPH的敏感度和特异度分别为87.7%（64/73）和90.9%（20/22）；3D MATCH与3D MPRAGE的SNR、CNR、CR差异均有统计学意义，MPRAGE图像上SNR与CNR高于MATCH序列，而MATCH的CR高于MPRAGE。结论与MPRAGE序列相比较，MATCH序列对于斑块内出血具有同样的诊断效能。

ObjectiveTo compare the diagnostic performance of multi-contrast atherosclerosis characterization （MATCH） and magnetization-prepared rapid acquisition gradient-echo （MPRAGE） for the detection of IPH with histologic analysis as the reference standard. MethodsThirty individuals were collected in this study. They were diagnosed to have carotid stenosis〉50% by ultrasound and scheduled for carotid endarterectomy from 2014 to 2015. 3 T carotid MR examinations using MPRAGE, MATCH and 3D TOF were performed in these patients. Axial images covered all plaques and centered at the bifurcation of the carotid artery. All image data sets were processed on a semi-automatic software （MRI-Plaque View, VPDiagnostics, US） to analyze the component of IPH for vulnerable plaques. The consistency between MATCH and MPRAGE was analyzed by using Cohen Kappa analysis. Comparison of the two sequences to the pathological results was performed in a similar manner. The sensitivity and specificity of the two sequences were obtained. The SNR,CNR and contrast ratio（CR） of the two regions of interest were calculated and Wilcoxon rank sum test was used to compare the difference between the two methods.ResultsAmong 30 patients, a total of 602 available sections and 95 correponding histology specimens were included in the analysis. When all 602 available sections were included in the analysis, MATCH yielded good agreement with MPRAGE（Kappa=0.773） on the detection of IPH. With pathological specimens as the gold standard, moderate to good agreement was shown for both MATCH and MPRAGE （Kappa=0.778, 0.685）. The sensitivity and specificity for the detection of IPH was 93.2% （68/73） and 90.9% （20/22） for MATCH. For MPRAGE, the sensitivity and specificity was 87.7%（64/73） and 90.9%（20/22） respectively. The difference between MATCH and MPRAGE was statistically significant for SNR, CNR and CR. That is to say, SNR and CNR of MPRAGE were higher than those of MATCH（P〈0.05）, while CR of MATCH was higher than that of MPRAGE（P〈0.05）. ConclusionCompared to the MPRAGE sequence, MATCH technique demonstrates similar diagnostic performance for the detection of IPH.