Extracellular Volume Fractions in Chronic Myocardial Infarction
Extracellular Volume Fractions in Chronic Myocardial Infarction
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DOI：
10.1097/rli.0b013e3182631c37
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发表时间：
2012-09-01
影响因子：
6.7
通讯作者：
Wintersperger, Bernd J.
中科院分区：
文献类型：
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作者：
Bauner, Kerstin Ulrike;Biffar, Andreas;Wintersperger, Bernd J.
目的：应用包括定量细胞外体积分数(ECV)在内的平扫和增强后T1图技术对慢性心肌梗死(CMI)进行评估和勾画。材料和方法：对26例CMI患者在增强前和增强后10分钟分别在3个短轴层面上采用改良Look-Locker反转恢复序列进行1.5T扫描。使用反转恢复梯度回波序列(参考标准)进行晚期Gd增强成像。计算平扫和增强后的T1图，定义CMI为T1值大于3SD的区域，与正常心肌(MYO)不同。测量CMI、MYO和血池的T1值，计算CMI和MYO的ECV。T1值和ECV的统计分析采用双尾t检验。计算平扫和增强后T1图检测CMI的灵敏度和特异度。结果：两组的T1值比较，差异有统计学意义(1,159+/-vs1001+/-47毫秒，P<；0.001；238+/-74vs379+/-59毫秒，P<；0.001)。在平扫Look-Locker反转恢复扫描和增强后图像上，T1图检测CMI的敏感性和特异性分别为41.7%和100%，95.8%和99.3%。平均ECV为28%+/-5%和53%+/-10%(P<；0.001)。ROC分析显示T1值和ECV曲线下面积分别为0.937和0.997，差异无统计学意义(P=0.137)。T1值检测CMI的敏感性和特异性分别为92.3%和92.3%，ECV分别为95.5%和100%，临界值为305毫秒或小于或大于42%。结论：慢性心肌梗死患者的增强后T1值和ECV与正常MYO的相应值有显著差异。这两个参数都可以准确地检测CMI，ECV显示出略高的敏感性和特异性。平扫T1值缺乏对CMI勾画的准确性。
Objectives: The aim of this study was to assess and delineate chronic myocardial infarction (CMI) using precontrast and postcontrast T1 mapping techniques including quantification of extracellular volume fractions (ECVs).Materials and Methods: A total of 26 patients with CMI were examined at 1.5 T applying a modified Look-Locker Inversion Recovery sequence before and 10 minutes after contrast at 3 short-axis slice positions. An inversion recovery gradient recalled echo sequence (standard of reference) was used for imaging late gadolinium enhancement. Precontrast and postcontrast T1 maps were calculated, and CMI was defined as areas with T1 values more than 3 SDs different compared with normal myocardium (MYO). T1 values of CMI, MYO, and blood pool were measured, and ECVs of CMI and MYO were calculated. Two-tailed Student t test was used for statistical analysis of T1 values and ECVs. Sensitivities and specificities for detection of CMI on precontrast and postcontrast T1 maps were calculated. Receiver operating characteristic (ROC) analysis was performed for postcontrast T1 values and ECV for discrimination of CMI.Results: The comparison of T1 values of CMI and MYO revealed significant differences in precontrast and postcontrast scans (1159 +/- 64 vs 1001 +/- 47 milliseconds, P < 0.001, and 238 +/- 74 vs 379 +/- 59 milliseconds, P < 0.001). Sensitivities and specificities for detection of CMI on T1 mapping were 41.7% and 100% in precontrast Look-Locker Inversion Recovery scans and 95.8% and 99.3% in postcontrast images, respectively. Average ECV for MYO and CMI were 28% +/- 5% and 53% +/- 10% (P < 0.001). ROC analysis revealed nonsignificantly different areas under the curve of 0.937 and 0.997 for T1 values and ECV, respectively (P = 0.137). Sensitivities and specificities were 92.3% and 92.3% for detecting CMI by postcontrast T1 values and 95.5% and 100% for ECV, with cutoff values being 305 milliseconds or less and greater than 42%. Combined criteria did not result in any further improvement of sensitivity for CMI detection.Conclusions: Postcontrast T1 values and ECV of chronically infarcted MYO are significantly different compared with respective values of normal MYO. Both parameters allow for accurate detection of CMI with ECV showing marginally higher sensitivity and specificity. Precontrast T1 values lack accuracy in delineation of CMI.