From the Department of Radiology (D.M., D.D., B.P., R.T.G., A.M., R.C.N.) and Carl E. Ravin Advanced Imaging Laboratories (K.R.C.), Duke University Medical Center, Box 3808 Erwin Rd, Durham, NC 27710.
Radiology. 2017 Sep;284(3):737-747. doi: 10.1148/radiol.2017161872. Epub 2017 Mar 28.
Purpose To determine whether single-phase contrast material-enhanced dual-energy material attenuation analysis improves the characterization of small (1-4 cm) renal lesions compared with conventional attenuation measurements by using histopathologic analysis and follow-up imaging as the clinical reference standards. Materials and Methods In this retrospective, HIPAA-compliant, institutional review board-approved study, 136 consecutive patients (95 men and 41 women; mean age, 54 years) with 144 renal lesions (111 benign, 33 malignant) measuring 1-4 cm underwent single-energy unenhanced and contrast-enhanced dual-energy computed tomography (CT) of the abdomen. For each renal lesion, attenuation measurements were obtained; attenuation change of greater than or equal to 15 HU was considered evidence of enhancement. Dual-energy attenuation measurements were also obtained by using iodine-water, water-iodine, calcium-water, and water-calcium material basis pairs. Mean lesion attenuation values and material densities were compared between benign and malignant renal lesions by using the two-sample t test. Diagnostic accuracy of attenuation measurements and dual-energy material densities was assessed and validated by using 10-fold cross-validation to limit the effect of optimistic bias. Results By using cross-validated optimal thresholds at 100% sensitivity, iodine-water material attenuation images significantly improved specificity for differentiating between benign and malignant renal lesions compared with conventional enhancement measurements (93% [103 of 111]; 95% confidence interval: 86%, 97%; vs 81% [90 of 111]; 95% confidence interval: 73%, 88%) (P = .02). Sensitivity with iodine-water and calcium-water material attenuation images was also higher than that with conventional enhancement measurements, although the difference was not statistically significant. Conclusion Contrast-enhanced dual-energy CT with material attenuation analysis improves specificity for characterization of small (1-4 cm) renal lesions compared with conventional attenuation measurements. RSNA, 2017 Online supplemental material is available for this article.
目的 本研究旨在通过病理分析和随访影像学检查作为临床参考标准，评估单期对比增强双能物质衰减分析是否优于常规衰减测量，从而提高对直径为 1~4cm 的小肾脏病变的特征描述能力。
材料与方法 本回顾性研究符合 HIPAA 规定和机构审查委员会的批准，共纳入 136 例连续患者（95 例男性，41 例女性；平均年龄，54 岁），这些患者共 144 个肾脏病变（111 个良性病变，33 个恶性病变），直径为 1~4cm，均接受了腹部单能平扫和对比增强双能 CT 检查。对每个肾脏病变均进行了衰减测量；增强程度大于或等于 15HU 被认为是增强的证据。还使用碘水、水碘、钙水和水钙物质基对获得双能衰减测量值。使用两样本 t 检验比较良性和恶性肾脏病变之间的平均病变衰减值和物质密度。通过 10 倍交叉验证评估和验证衰减测量和双能物质密度的诊断准确性，以限制乐观偏差的影响。
结果 在以 100%敏感性为交叉验证最优阈值的情况下，与常规增强测量相比，碘水物质衰减图像显著提高了区分良恶性肾脏病变的特异性（93%[111 个中的 103 个]；95%置信区间：86%，97%；vs 81%[111 个中的 90 个]；95%置信区间：73%，88%）（P=.02）。碘水和钙水物质衰减图像的敏感性也高于常规增强测量，尽管差异无统计学意义。
结论 与常规衰减测量相比，对比增强双能 CT 联合物质衰减分析可提高对直径为 1~4cm 的小肾脏病变的特征描述的特异性。
放射学学会，2017 年
在线补充材料可在本文中获取。
