Signal characteristics of focal liver lesions on double echo T2-weighted conventional spin echo MRI: Observer performance versus quantitative measurements of T2 relaxation times
Signal characteristics of focal liver lesions on double echo T2-weighted conventional spin echo MRI: Observer performance versus quantitative measurements of T2 relaxation times
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DOI：
10.1097/00004728-200003000-00004
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发表时间：
2000-03-01
影响因子：
1.3
通讯作者：
Yucel, EK
中科院分区：
文献类型：
--
作者：
Fenlon, HM;Tello, R;Yucel, EK
目的：本研究的目的是评估专家读者在双回波T2加权常规自旋回波（CSE） MR图像上基于病变信号强度的视觉评估来区分良性和恶性肝脏病变的能力，并将读者的表现与T2松弛时间的定量测量进行比较。方法：由三名独立读者对双回声t2加权CSE序列（TR 3,600 ms/TE 50,160 ms）的67张MR检查结果进行定性分析，显示85个肝脏病变（37个血管瘤，32个恶性肿瘤，15个囊肿，1个局灶性结节增生）。计算每个病变的T2弛豫时间。比较专家阅读者的接收者工作特征（ROC）分析计算的T2松弛时间。结果：T2值对肝脏病变特征的评价明显优于主观解读分析（ROC下面积= 0.93 vs. 0.81、0.78和0.75;p < 0.0001）。使用125 ms的T2阈值，T2值对恶性病变的敏感性为100%，特异性为71%，准确性为84%。相比之下，三种阅读器对恶性病变的敏感性为76-83%，特异性为61-72%，总体准确率为71-80%。结论：尽管有专家分析，但在使用中间TEs （50/160 ms）时，对肝脏病变信号特征的主观评价容易不准确，缺乏确定性和一致性。应定量测量T2松弛时间，以准确和自信地区分良性和恶性肝脏病变。使用比以前推荐的更高的T2阈值，以避免恶性肿瘤的错误分类。
Purpose: The purpose of this work was to evaluate the ability of expert readers to differentiate benign from malignant liver lesions based on visual assessment of lesion signal intensity on double echo T2-weighted conventional spin echo (CSE) MR images and to compare reader performance with quantitative measurements of T2 relaxation times.Method: Sixty-seven MR examinations demonstrating 85 liver lesions (37 hemangiomas, 32 malignancies, 15 cysts, and 1 focal nodular hyperplasia) on double echo T2-weighted CSE sequences (TR 3,600 ms/TE 50, 160 ms) were qualitatively reviewed by three independent readers. T2 relaxation tines were calculated for each lesion. Receiver operating characteristic (ROC) analyses of expert readers were compared with calculated T2 relaxation times.Results: T2 values performed significantly better than subjective reader analysis for Liver lesion characterization (area under ROC = 0.93 vs. 0.81, 0.78, and 0.75; p < 0.0001). With use of a T2 threshold of 125 ms, the sensitivity of T2 values for malignant lesions was 100%, specificity 71%, and accuracy 84%. By comparison, the sensitivity of the three readers for malignant lesions was 76-83%, with a specificity of 61-72% and an overall accuracy of 71-80%.Conclusion: Despite expert reader analyses, subjective evaluations of liver lesion signal characteristics are prone to inaccuracy and lack certainty and consistency when intermediate TEs (50/160 ms) are used. Quantitative measurements of T2 relaxation times should be performed to accurately and confidently differentiate: benign from malignant liver lesions. Use of a higher T2 threshold than previously recommended is required to avoid misclassification of malignancies.