1 Department of Radiology, San Antonio Military Medical Center, San Antonio, TX.
2 Present address: Department of Radiology, University of Colorado Hospital, Anschutz Medical Campus, 12401 E 17th Ave, Aurora, CO 80045.
AJR Am J Roentgenol. 2019 Jan;212(1):130-134. doi: 10.2214/AJR.18.20079. Epub 2018 Nov 7.
Incidentally discovered renal lesions on lumbar spine MRI are a common occurrence. Many follow-up recommendations are generated by radiologists encountering renal lesions to help characterize the finding as a benign cyst or a more complex, potentially malignant lesion. We hypothesized that analysis of T2-weighted imaging features of incidentally discovered renal lesions could reliably distinguish complex renal lesions from simple cysts.
Two independent readers retrospectively evaluated 149 renal lesions identified on lumbar spine MRI examinations. Presence or absence of a complex renal lesion was determined using T2-weighted imaging only. Using dedicated renal cross-sectional imaging examinations as the reference standard, statistical analysis was performed to determine the accuracy of lumbar spine MRI in predicting a complex and potentially neoplastic renal lesion.
Of 149 renal lesions, 115 were simple cysts, and 34 were complex renal lesions (20 Bosniak II cysts, nine renal cell carcinomas, three Bosniak IIF cysts, and two angiomyolipomas). Lumbar spine MRI readers identified 72 lesions as simple cysts and 77 lesions as complex renal lesions. Reader sensitivity for detection of a complex renal lesion on lumbar spine MRI was 94% (95% CI, 80-99%); specificity, 63% (95% CI, 53-72%); positive predictive value, 43% (95% CI, 37-49%); and negative predictive value, 97% (95% CI, 90-99%). Readers correctly identified all neoplastic and potentially neoplastic lesions (≥ Bosniak IIF). Interreader agreement was excellent (κ = 0.84).
Follow-up imaging may not be required in all cases of incidentally discovered renal lesions on lumbar spine MRI. Analysis of T2-weighted imaging alone appears to reliably rule out neoplastic and potentially neoplastic complex renal lesions.
在腰椎 MRI 上偶然发现的肾脏病变是很常见的。放射科医生在遇到肾脏病变时会生成许多随访建议，以帮助确定病变是良性囊肿还是更复杂、可能恶性的病变。我们假设分析偶然发现的肾脏病变的 T2 加权成像特征可以可靠地区分复杂的肾脏病变与单纯囊肿。
两位独立的读者回顾性评估了腰椎 MRI 检查中发现的 149 个肾脏病变。仅使用 T2 加权成像确定是否存在复杂的肾脏病变。使用专用的肾脏横断面成像检查作为参考标准，进行统计学分析，以确定腰椎 MRI 在预测复杂和潜在恶性肾脏病变方面的准确性。
在 149 个肾脏病变中，115 个为单纯囊肿，34 个为复杂肾脏病变（20 个 Bosniak II 囊肿、9 个肾细胞癌、3 个 Bosniak IIF 囊肿和 2 个血管平滑肌脂肪瘤）。腰椎 MRI 读者将 72 个病变识别为单纯囊肿，77 个病变识别为复杂肾脏病变。腰椎 MRI 读者检测复杂肾脏病变的敏感性为 94%（95%CI，80-99%）；特异性为 63%（95%CI，53-72%）；阳性预测值为 43%（95%CI，37-49%）；阴性预测值为 97%（95%CI，90-99%）。读者正确识别了所有的肿瘤和潜在肿瘤病变（≥ Bosniak IIF）。两位读者之间的一致性很好（κ=0.84）。
在腰椎 MRI 上偶然发现的肾脏病变并非所有病例都需要进行随访成像。单独分析 T2 加权成像似乎可以可靠地排除肿瘤和潜在肿瘤性复杂肾脏病变。
