Histogram Analysis of Small Solid Renal Masses: Differentiating Minimal Fat Angiomyolipoma From Renal Cell Carcinoma
Histogram Analysis of Small Solid Renal Masses: Differentiating Minimal Fat Angiomyolipoma From Renal Cell Carcinoma
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DOI：
10.2214/ajr.11.6887
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发表时间：
2012-02-01
影响因子：
5
通讯作者：
Neville, Amy M.
中科院分区：
文献类型：
--
作者：
Chaudhry, Humaira S.;Davenport, Matthew S.;Neville, Amy M.
客观的。我们研究的目的是利用平扫 CT 的衰减测量直方图分析来回顾性确定微小脂肪肾血管平滑肌脂肪瘤是否可以与小肾肿块中的透明细胞癌或乳头状肾细胞癌 (RCC) 区分开来。材料和方法。使用机构数据库将 20 个最小脂肪肾血管平滑肌脂肪瘤与 22 个透明细胞 RCC 和 23 个乳头状 RCC 进行比较。所有肿块均经过组织学证实，所有最小脂肪肾血管平滑肌脂肪瘤均缺乏肉眼可见脂肪的放射学证据。使用衰减测量直方图分析，两名盲法放射科医生确定了每个肾脏肿块内负像素的百分比。记录低于 0、-5、-10、-15、-20、-25 和 -30 HU 衰减阈值的负像素百分比。针对每个阈值生成诊断最小脂肪肾血管平滑肌脂肪瘤的敏感性、特异性、阳性预测值、阴性预测值和受试者操作特征曲线。学生 t 检验用于比较放射科医生和队列。先前发表的衰减和像素计数阈值据报道具有接近 100% 的特异性，可用于区分最小脂肪肾血管平滑肌脂肪瘤和 RCC。结果。最小脂肪肾血管平滑肌脂肪瘤的平均最大横向病变直径为 1.8 cm（SD，0.5 cm；范围，1.1-3.0 cm），透明细胞 RCC（SD，0.5 cm；范围，1.0-2.9 cm）为 2.1 cm，乳头状 RCC 为 2.1 cm（SD，0.7 cm；范围，1.3-3.9 cm）。在任一放射科医生选定的任何衰减阈值下，最小脂肪肾血管平滑肌脂肪瘤和透明细胞 RCC 之间或最小脂肪肾血管平滑肌脂肪瘤和乳头状 RCC 之间的负像素百分比均未发现显着差异 (p = 0.210-0.499)。放射科医生 1 和放射科医生 2 使用的感兴趣区域大小显着不同 (p < 0.001)，但放射科医生均无法区分微小脂肪肾血管平滑肌脂肪瘤和 RCC。先前公布的阈值无法以 100% 的特异性区分微小脂肪肾血管平滑肌脂肪瘤和肾细胞癌。结论。衰减测量直方图分析不能可靠地区分微脂肾血管平滑肌脂肪瘤和肾细胞癌。
OBJECTIVE. The objective of our study was to retrospectively determine whether minimal fat renal angiomyolipoma can be differentiated from clear cell or papillary renal cell carcinoma (RCC) in small renal masses using attenuation measurement histogram analysis on unenhanced CT.MATERIALS AND METHODS. Twenty minimal fat renal angiomyolipomas were compared with 22 clear cell RCCs and 23 papillary RCCs using an institutional database. All masses were histologically confirmed and all minimal fat renal angiomyolipomas lacked radiographic evidence of macroscopic fat. Using attenuation measurement histogram analysis, two blinded radiologists determined the percentage of negative pixels within each renal mass. The percentages of negative pixels below attenuation thresholds of 0, -5, -10, -15, -20, -25, and -30 HU were recorded. Sensitivity, specificity, positive predictive value, negative predictive value, and receiver operator characteristic curves for the diagnosis of minimal fat renal angiomyolipoma were generated for each threshold. The Student t test was used to compare radiologists and cohorts. Previously published attenuation and pixel-counting thresholds reported as having a specificity of near 100% for discriminating between minimal fat renal angiomyolipomas and RCCs were analyzed.RESULTS. The mean maximal transverse lesion diameter was 1.8 cm for minimal fat renal angiomyolipomas (SD, 0.5 cm; range, 1.1-3.0 cm), 2.1 cm for clear cell RCCs (SD, 0.5 cm; range, 1.0-2.9 cm), and 2.1 cm for papillary RCCs (SD, 0.7 cm; range, 1.3-3.9 cm). No significant difference in the percentage of negative pixels was found between minimal fat renal angiomyolipomas and clear cell RCCs or between minimal fat renal angiomyolipomas and papillary RCCs at any of the selected attenuation thresholds for either radiologist (p = 0.210-0.499). Radiologist 1 and radiologist 2 used significantly different region-of-interest sizes (p < 0.001), but neither radiologist could differentiate minimal fat renal angiomyolipoma from RCC. No previously published threshold allowed discrimination between minimal fat renal angiomyolipoma and RCC with 100% specificity.CONCLUSION. Attenuation measurement histogram analysis cannot reliably differentiate minimal fat renal angiomyolipoma from RCC.