Department of Radiology, Thomas Jefferson University Hospital, 132 S 10th St, Philadelphia, PA 19107, USA.
Radiology. 2010 May;255(2):501-7. doi: 10.1148/radiol.09091109. Epub 2010 Feb 16.
To retrospectively determine whether benign exophytic renal masses can be distinguished from renal cell carcinoma (RCC) on the basis of angular interface at single-shot fast spin-echo (SE) T2-weighted magnetic resonance (MR) imaging.
This retrospective study was compliant with HIPAA and was approved by the institutional review board. Patient informed consent was waived. A total of 162 exophytic (2 cm or greater) renal masses in 152 patients (103 men, 49 women; mean age, 58 years; age range, 23-85 years) were included. Two radiologists independently recorded the mass size and angular interface on single-shot fast SE T2-weighted MR images. Surgical pathologic report and MR follow-up were used as reference standards. Logistic regression analysis was used to examine the usefulness of these variables for differentiating benign masses from RCCs. Diagnostic performance was analyzed by comparing values for area under receiver operating characteristic curve (A(z)). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of angular interface for diagnosing benign masses were calculated. Reader agreement was assessed with kappa-weighted statistics and intraclass correlation coefficients (ICCs).
Of 162 masses, 65 were benign, and 97 were RCCs. The sensitivity, specificity, PPV, NPV, and A(z) of angular interface for diagnosing benign masses were 78%, 100%, 100%, 87%, and 0.813, respectively. Angular interface (P < .001) was a significant predictor of benign renal mass but mass size (P = .66) was not. There was almost perfect interobserver agreement for mass size (ICC = 0.96) and angular interface (kappa = 0.91).
The presence of an angular interface with the renal parenchyma at single-shot fast SE T2-weighted MR imaging is a strong predictor of benignity in an exophytic renal mass 2 cm or greater in diameter with high specificity and diagnostic accuracy.
回顾性分析单次快速自旋回波（SE）T2 加权磁共振（MR）成像的角状界面是否能区分肾外生性良性肿块与肾细胞癌（RCC）。
本回顾性研究符合 HIPAA 规定，并经机构审查委员会批准。豁免了患者的知情同意。共纳入 152 例患者（103 例男性，49 例女性；平均年龄 58 岁；年龄范围：23-85 岁）的 162 个外生性（≥2cm）肾肿块。两位放射科医生分别记录单次快速 SE T2 加权 MR 图像上的肿块大小和角状界面。手术病理报告和 MR 随访结果被用作参考标准。使用逻辑回归分析来评估这些变量在区分良性肿块与 RCC 方面的作用。通过比较受试者工作特征曲线下面积（A(z)）值来分析诊断性能。计算角状界面诊断良性肿块的敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和准确性。采用 Kappa 加权统计量和组内相关系数（ICC）评估观察者间的一致性。
162 个肿块中，65 个为良性，97 个为 RCC。角状界面诊断良性肿块的敏感性、特异性、PPV、NPV 和 A(z)分别为 78%、100%、100%、87%和 0.813。角状界面（P＜0.001）是良性肾肿块的重要预测因子，而肿块大小（P=0.66）则不是。观察者 1 对肿块大小（ICC=0.96）和角状界面（kappa=0.91）的一致性几乎为完美。
单次快速 SE T2 加权 MR 成像上存在与肾实质的角状界面是直径≥2cm 的外生性肾肿块为良性的强有力预测因子，具有高特异性和诊断准确性。
