T2 quantification for improved detection of myocardial edema
T2 quantification for improved detection of myocardial edema
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DOI：
10.1186/1532-429x-11-56
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发表时间：
2009-12-30
影响因子：
6.4
通讯作者：
Simonetti, Orlando P.
中科院分区：
文献类型：
--
作者：
Giri, Shivraman;Chung, Yiu-Cho;Simonetti, Orlando P.
背景：T2加权(T2W)磁共振成像(MRI)脉冲序列已被用于检测急性心肌梗死患者的水肿，并鉴别急性和慢性心肌梗死。T2W序列存在的问题包括：(1)相控阵线圈引起的信号强度变异性；(2)缓慢运动的室腔血液可模拟和掩盖心内膜下心肌T2升高的高信号；(3)运动伪影；(4)T2W图像解释的主观性。在这项工作中，我们展示了定量T2标测技术的优势，可以准确可靠地检测水肿性心肌组织区域，而不受定性T2W成像的限制。方法：对T2标测方法在模体上进行评估；然后对这些方法中最好的方法进行优化，以用于活体成像。优化后的方案被用于研究健康受试者的空间、视点依赖和受试者间的变异性和运动敏感性。利用由此获得的洞察力，T2标测在猪急性心肌梗死(AMI)模型和3名急性心肌梗死患者中得到了应用。结果：T2-准备的SSFP在估计模体的T2方面比多回波快速自旋回波更准确。人体心肌的T2为52.18+/-3.4ms(范围为48.96~55.67ms)，不同受试者之间的变异性与心率无关。与T2W图像不同，T2图没有显示任何由于相控阵线圈的可变灵敏度而导致的信号变化，并且对心脏运动不敏感。在三只猪和三名急性心肌梗死患者中，梗死区的T2显著高于远端心肌。结论：定量T2标测解决了与心脏T2W成像相关的众所周知的问题，并为提高检测心肌水肿的准确性提供了可能性。
Background: T2-Weighted (T2W) magnetic resonance imaging (MRI) pulse sequences have been used to detect edema in patients with acute myocardial infarction and differentiate acute from chronic infarction. T2W sequences have suffered from several problems including (i) signal intensity variability caused by phased array coils, (ii) high signal from slow moving ventricular chamber blood that can mimic and mask elevated T2 in sub-endocardial myocardium, (iii) motion artifacts, and (iv) the subjective nature of T2W image interpretation. In this work we demonstrate the advantages of a quantitative T2 mapping technique to accurately and reliably detect regions of edematous myocardial tissue without the limitations of qualitative T2W imaging.Methods: Methods of T2 mapping were evaluated on phantoms; the best of these protocols was then optimized for in vivo imaging. The optimized protocol was used to study the spatial, viewdependent, and inter-subject variability and motion sensitivity in healthy subjects. Using the insights gained from this, the utility of T2 mapping was demonstrated in a porcine model of acute myocardial infarction (AMI) and in three patients with AMI.Results: T2-prepared SSFP demonstrated greater accuracy in estimating the T2 of phantoms than multi-echo turbo spin echo. The T2 of human myocardium was found to be 52.18 +/- 3.4 ms (range: 48.96 ms to 55.67 ms), with variability between subjects unrelated to heart rate. Unlike T2W images, T2 maps did not show any signal variation due to the variable sensitivity of phased array coils and were insensitive to cardiac motion. In the three pigs and three patients with AMI, the T2 of the infarcted region was significantly higher than that of remote myocardium.Conclusion: Quantitative T2 mapping addresses the well-known problems associated with T2W imaging of the heart and offers the potential for increased accuracy in the detection of myocardial edema.