Woo Sungmin, Kim Sang Youn, Cho Jeong Yeon, Kim Seung Hyup
1 Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
2 Institute of Radiation Medicine and Kidney Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea.
Acta Radiol. 2018 May;59(5):627-634. doi: 10.1177/0284185117723371. Epub 2017 Jul 27.
Background Recent literature suggests that intratumoral hemorrhage detection may be helpful in differentiating papillary renal cell carcinoma (pRCC) from fat-poor angiomyolipoma (fpAML). Purpose To determine whether intratumoral hemorrhage detected using chemical shift magnetic resonance imaging (MRI) and T2*-weighted (T2W) gradient echo (GRE) can be used to differentiate pRCC from fpAML. Material and Methods This retrospective study included 42 patients with pRCC (n = 28) and fpAML (n = 14) who underwent MRI followed by surgery. Two blinded radiologists independently assessed the presence of intratumoral hemorrhage using chemical shift MRI (decrease in signal intensity from opposed- to in-phase) and T2W GRE ("blooming"). Consensus reading was determined for discrepant cases. MRI findings were compared using Chi-square test. Inter-observer agreement was assessed using kappa statistics. Results Inter-observer agreement was substantial for both sequences ( k = 0.622 and 0.793, P < 0.001). For chemical shift MRI, the prevalence of intratumoral hemorrhage was significantly greater in pRCC than in fpAML (71.4% versus 28.6%, P = 0.019 for reader 1; 64.3% versus 14.3%, P = 0.003 for reader 2; and 75% versus 21.4%, P = 0.002 for the consensus). T2W GRE showed a similar tendency (46.4% versus 14.3%, P = 0.049 for both readers; and 50% versus 14.3%, P = 0.042 for the consensus). Using the consensus reading, sensitivity and specificity of determining pRCC were 75% and 78.6% for chemical shift MRI and 50% and 85.7% for T2W GRE. Conclusion The prevalence of intratumoral hemorrhage identified from chemical shift MRI or T2*W GRE was significantly different between pRCC and fpAML. These hemorrhage-sensitive MRI sequences may be used as an adjunctive tool for discriminating between the two entities.
背景 近期文献表明，肿瘤内出血的检测可能有助于鉴别乳头状肾细胞癌（pRCC）与乏脂性血管平滑肌脂肪瘤（fpAML）。目的 确定使用化学位移磁共振成像（MRI）和T2加权（T2W）梯度回波（GRE）检测到的肿瘤内出血是否可用于鉴别pRCC和fpAML。材料与方法 这项回顾性研究纳入了42例接受MRI检查后接受手术的pRCC患者（n = 28）和fpAML患者（n = 14）。两名盲法放射科医生使用化学位移MRI（从反相位到同相位信号强度降低）和T2W GRE（“ blooming”）独立评估肿瘤内出血的存在情况。对存在差异的病例进行一致性解读。使用卡方检验比较MRI结果。使用kappa统计量评估观察者间的一致性。结果 两个序列的观察者间一致性均较高（k = 0.622和0.793，P < 0.001）。对于化学位移MRI，pRCC中肿瘤内出血的发生率显著高于fpAML（读者1：71.4% 对28.6%，P = 0.019；读者2：64.3% 对14.3%，P = 0.003；一致性解读：75% 对21.4%，P = 0.002）。T2W GRE显示出类似趋势（两位读者均为46.4% 对14.3%，P = 0.049；一致性解读：50% 对14.3%，P = 0.042）。使用一致性解读，化学位移MRI鉴别pRCC的敏感性和特异性分别为75%和78.6%，T2W GRE分别为50%和85.7%。结论 化学位移MRI或T2W GRE识别出的pRCC和fpAML肿瘤内出血发生率存在显著差异。这些对出血敏感的MRI序列可作为鉴别这两种疾病的辅助工具。
