T1 Hyperintense Renal Lesions: Characterization with Diffusion-weighted MR Imaging versus Contrast-enhanced MR Imaging
T1 Hyperintense Renal Lesions: Characterization with Diffusion-weighted MR Imaging versus Contrast-enhanced MR Imaging
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DOI：
10.1148/radiol.2513080724
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发表时间：
2009-06-01
期刊：
影响因子：
19.7
通讯作者：
Taouli, Bachir
中科院分区：
文献类型：
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作者：
Kim, Sooah;Jain, Monica;Taouli, Bachir
目的：以组织病理学分析和随访成像为参考标准，比较磁共振弥散加权成像(DW)和增强磁共振成像(MR)测量的表观弥散系数(ADC)在非含脂肪T1高信号肾脏病变中的表现。材料和方法：这项符合HIPAA标准的回顾性研究获得机构审查委员会的批准，免除了知情同意的要求。两位独立的观察者回顾评估了41例非含脂肪T1高信号肾脏病变患者的MR图像。MR检查包括获取DW和增强后的T1加权图像。对于每个指标性病变，观察者评估(A)平均(+/-标准差)的ADC，(B)强化比率，以及(C)减影图像是否存在强化(置信度分数，1-5)。以肾细胞癌(RCC)的组织病理学分析和良性病变的随访影像为参考标准。比较良性病变和肾癌的ADC值。采用受试者工作特征(ROC)曲线分析评价DW图像、增强率和减影对肾癌诊断的准确性。结果：共诊断病灶38个，平均直径3.9 cm，其中良性T1高信号囊肿38个，肾癌26个。肾癌的平均ADC值明显低于良性囊肿组([1.75+/-0.57]×10(-3)mm(2)/s vs[2.50+/-0.53]×10(-3)mm(2)/s，P<；0.0001)。囊性和实性肾癌的ADC值分别为[1.37+/-0.55]×10(-3)mm(2)/s vs[2.45+/-0.63]×10(-3)mm(2)/s，P<；0.0001。当两个观察者的数据合并在一起时，DW成像的ROC曲线下面积、敏感性和特异性分别为0.846、71%和91%；增强率(排泄期)分别为0.865、65%和96%；减影分别为0.861、83%和89%(P=0.48和P=0.85)。DW成像与减影结合后的ROC曲线下面积、灵敏度和特异度分别为0.893%、87%和92%，与单独使用减影相比有显著提高(P=0.041)。结论：在T1高信号肾脏病变的定性方面，DW成像的表现与增强率相当，两种方法的灵敏度均低于图像减影，但无统计学意义。(C)RSNA，2009年
Purpose: To compare the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted (DW) magnetic resonance (MR) imaging in the characterization of non-fat-containing T1 hyperintense renal lesions with that of contrast material-enhanced MR imaging, with histopathologic analysis and follow-up imaging as the reference standards.Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant retrospective study, and the informed consent requirement was waived. Two independent observers retrospectively assessed MR images obtained in 41 patients with non-fat-containing T1 hyperintense renal lesions. The MR examination included acquisition of DW and contrast-enhanced T1-weighted images. For each index lesion, the observers assessed the (a) mean (+/- standard deviation) of ADC, (b) enhancement ratio, and (c) subtracted images for the presence of enhancement (confidence score, 1-5). Histopathologic analysis of renal cell carcinomas (RCCs) and follow-up imaging for benign lesions were the reference standards. ADCs of benign lesions and RCCs were compared. Receiver operating characteristic (ROC) curve analysis was performed to assess the accuracy of DW imaging, enhancement ratio, and subtraction for the diagnosis of RCC.Results: A total of 64 lesions (mean diameter, 3.9 cm), including 38 benign T1 hyperintense cysts and 26 RCCs, were assessed. Mean ADCs of RCCs were significantly lower than those of benign cysts ([1.75 +/- 0.57] X 10(-3) mm(2)/sec vs [2.50 +/- 0.53] X 10(-3) mm(2)/sec, P < .0001). ADCs of solid and cystic portions of complex cystic RCCs were significantly different ([1.37 +/- 0.55] X 10(-3) mm(2)/sec vs [2.45 +/- 0.63] X 10(-3) mm(2)/sec, P < .0001). When data from both observers were pooled, area under the ROC curve, sensitivity, and specificity were 0.846, 71%, and 91%, respectively, for DW imaging; 0.865, 65%, and 96%, respectively, for enhancement ratio (at the excretory phase); and 0.861, 83%, and 89%, respectively, for subtraction (P = .48 and P = .85, respectively). The combination of DW imaging and subtraction resulted in area under the ROC curve, sensitivity, and specificity of 0.893, 87%, and 92%, respectively, with significantly improved reader confidence compared with subtraction alone (P = .041).Conclusion: The performance of DW imaging was equivalent to that of enhancement ratio in the characterization of T1 hyperintense renal lesions, with both methods having lower sensitivity than image subtraction without reaching significance. (C) RSNA, 2009