From the Department of Radiology, Seoul National University Hospital, Seoul, Korea (I.J., J.M.L.); Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea (S.Y.K.); Department of Radiology, Samsung Medical Center, Seoul, Korea (T.W.K., Y.K.K.); Department of Radiology, Korea University Anam Hospital, Seoul, Korea (B.J.P.); Department of Radiology, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, Korea (Y.J.L.); Department of Radiology, Seoul St. Mary's Hospital, Seoul, Korea (J.I.C.); Department of Radiology, Korea University Guro Hospital, Seoul, Korea (C.H.L.); Department of Radiology, Konkuk University School of Medicine, Seoul, Korea (H.S.P.); Department of Pathology, Seoul National University Hospital and Seoul National University College of Medicine, Seoul, Korea (K.L., H.K.); Department of Pathology, Asan Medical Center, Seoul, Korea (E.Y., H.J.K.); Department of Pathology, Samsung Medical Center, Seoul, Korea (S.Y.H.); Department of Pathology, Korea University Anam Hospital, Seoul, Korea (J.Y.K.); Department of Pathology, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, Korea (S.A.); Department of Pathology, Seoul St. Mary's Hospital, Seoul, Korea (E.S.J.); Department of Pathology, Korea University Guro Hospital, Seoul, Korea (B.H.K.); and Department of Pathology, Konkuk University Hospital, Seoul, Korea (H.S.H.).
Radiology. 2020 Aug;296(2):335-345. doi: 10.1148/radiol.2020192275. Epub 2020 Jun 2.
Background Hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) at gadoxetic acid-enhanced MRI may indicate hepatocellular carcinoma (HCC) or nonmalignant cirrhosis-associated nodules. Purpose To assess the distribution of pathologic diagnoses of HBP hypointense nodules without APHE at gadoxetic acid-enhanced MRI and to evaluate clinical and imaging features in differentiating their histologic grades. Materials and Methods This retrospective multicenter study included pathologic analysis-confirmed HBP hypointense nodules without APHE (≤30 mm) in patients with chronic liver disease or cirrhosis screened between January 2008 and June 2016. Central pathologic review by 10 pathologists determined final histologic grades as progressed HCC, early HCC, high-grade dysplastic nodule (DN), and low-grade DN or regenerative nodule. Gadoxetic acid-enhanced MRI features were analyzed by three radiologists. Multivariable logistic regression analyses with elastic net regularization were performed to identify clinical and imaging features for differentiating histologic grades. Results There were 298 patients (mean age, 59 years ± 10; 226 men) with 334 nodules evaluated, and progressed HCCs were diagnosed in 44.0% (147 of 334), early HCCs in 20.4% (68 of 334), high-grade DNs in 27.5% (92 of 334), and low-grade DNs or regenerative nodules in 8.1% (27 of 334). Serum α-fetoprotein level 100 ng/mL or greater (odds ratio, 2.7; = .01) and MRI features including well-defined margin (odds ratio, 5.5; = .003), hypointensity at precontrast T1-weighted imaging (odds ratio, 3.2; < .001), intermediate hyperintensity at T2-weighted imaging (odds ratio, 3.4; < .001), and restricted diffusion (odds ratio, 1.9; = .04) were independent predictors for progressed HCC at multivariable analysis. Conclusion In patients at high risk for hepatocellular carcinoma (HCC), hepatobiliary phase hypointense nodules without arterial phase hyperenhancement at gadoxetic acid-enhanced MRI corresponded mainly to progressed HCCs, early HCCs, and high-grade dysplastic nodules. High α-fetoprotein level and some imaging features at MRI helped to differentiate progressed HCC from lower grade nodules. © RSNA, 2020 See also the editorial by Motosugi in this issue.
背景 在钆塞酸增强 MRI 的肝胆期呈低信号且无动脉期强化（APHE）的结节可能提示肝细胞癌（HCC）或非恶性肝硬化相关结节。目的 评估在钆塞酸增强 MRI 上肝胆期低信号且无 APHE 的结节的病理诊断分布，并评估在鉴别其组织学分级方面的临床和影像学特征。
材料与方法 本回顾性多中心研究纳入了 2008 年 1 月至 2016 年 6 月期间筛查出的患有慢性肝病或肝硬化的患者，这些患者经病理分析证实存在肝胆期低信号且无 APHE（≤30 mm）的结节。由 10 位病理学家进行中心病理复查，将最终组织学分级确定为进展期 HCC、早期 HCC、高级别异型增生结节（DN）和低级别 DN 或再生结节。由 3 位放射科医生分析钆塞酸增强 MRI 特征。采用弹性网络正则化的多变量逻辑回归分析确定用于鉴别组织学分级的临床和影像学特征。
结果 共纳入 298 例患者（平均年龄，59 岁±10 岁；226 例男性），共评估了 334 个结节，其中 44.0%（147/334）为进展期 HCC，20.4%（68/334）为早期 HCC，27.5%（92/334）为高级别 DN，8.1%（27/334）为低级别 DN 或再生结节。血清甲胎蛋白水平≥100 ng/mL（比值比，2.7； =.01）和 MRI 特征（包括边界清楚[比值比，5.5； =.003]、平扫 T1 加权成像呈低信号[比值比，3.2； <.001]、T2 加权成像呈中等高信号[比值比，3.4； <.001]和弥散受限[比值比，1.9； =.04]）是多变量分析中进展期 HCC 的独立预测因素。
结论 在 HCC 高危患者中，在钆塞酸增强 MRI 的肝胆期呈低信号且无 APHE 的结节主要与进展期 HCC、早期 HCC 和高级别异型增生结节相对应。高甲胎蛋白水平和 MRI 上的一些影像学特征有助于鉴别进展期 HCC 与低级别结节。
