1 Department of Radiology, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
2 Department of Gastroenterology, Osaka Red Cross Hospital, Osaka, Japan.
AJR Am J Roentgenol. 2018 Aug;211(2):347-357. doi: 10.2214/AJR.17.19341. Epub 2018 Apr 30.
The purpose of this study is to identify points useful in the imaging differentiation of hepatocellular carcinoma (HCC) showing hyperintensity on the hepatobiliary phase of gadoxetic acid-enhanced MRI and focal nodular hyperplasia (FNH) and FNH-like nodules.
We enrolled consecutive 51 pathologically diagnosed HCCs that were hyperintense on hepatobiliary phase imaging (47 patients, including 44 with cirrhosis) and 10 FNHs and eight FNH-like nodules (16 patients, including five with cirrhosis). Imaging findings of dynamic CT and gadoxetic acid-enhanced MRI were assessed by two radiologists and compared between HCC and FNH.
The apparent diffusion coefficient (ADC) was lower in hyperintense HCC than in FNH (p = 0.004). The enhancement patterns of hyperintense HCC and FNH at dynamic CT were significantly different (p < 0.0001), with 95.9% of HCCs and 22.2% of FNHs showing arterial phase enhancement with a washout pattern, and 4.1% of HCCs and 77.8% of FNHs showing arterial phase enhancement without a washout pattern. The frequency of coronalike enhancement was 84.3% in hyperintense HCCs versus 11.1% in FNHs (p < 0.0001). The signal distribution on the hepatobiliary phase was significantly different between hyperintense HCCs and FNHs (p = 0.0002). The frequency of a capsulelike rim was 88.2% versus 22.2%, that of a mosaic appearance was 72.5% versus 11.1%, and that of a central scar was 0% versus 55.6% in hyperintense HCCs versus FNHs (all p < 0.0001). Multivariate logistic regression analysis showed that ADC ratio (p = 0.03; odds ratio, 0.12) and enhancement pattern at dynamic CT (p = 0.04; odds ratio, 16.21) were the independent factors for differentiation between hyperintense HCC and FNH.
For the diagnosis of hyperintense HCC differentiated from FNH and FNH-like nodule, arterial phase enhancement and washout pattern at dynamic CT and decrease of ADC ratio would be important findings.
本研究旨在确定在钆塞酸增强 MRI 肝胆期呈高信号的肝细胞癌（HCC）和局灶性结节增生（FNH）及 FNH 样结节的影像鉴别中有用的特征。
我们纳入了 51 例经病理诊断为肝胆期成像高信号的 HCC（47 例患者，其中 44 例伴有肝硬化）和 10 例 FNH 及 8 例 FNH 样结节（16 例患者，其中 5 例伴有肝硬化）。两位放射科医生评估了动态 CT 和钆塞酸增强 MRI 的影像学表现，并比较了 HCC 和 FNH 的影像学表现。
高信号 HCC 的表观扩散系数（ADC）低于 FNH（p=0.004）。高信号 HCC 和 FNH 的动态 CT 增强模式有显著差异（p＜0.0001），95.9%的 HCC 和 22.2%的 FNH 呈动脉期增强伴洗脱模式，4.1%的 HCC 和 77.8%的 FNH 呈动脉期增强不伴洗脱模式。冠状位样强化在高信号 HCC 中的发生率为 84.3%，而在 FNH 中的发生率为 11.1%（p＜0.0001）。高信号 HCC 和 FNH 的肝胆期信号分布有显著差异（p=0.0002）。包膜样边缘的发生率在 HCC 中为 88.2%，在 FNH 中为 22.2%（均 p＜0.0001）；马赛克样外观的发生率在 HCC 中为 72.5%，在 FNH 中为 11.1%（均 p＜0.0001）；中央瘢痕的发生率在 HCC 中为 0%，在 FNH 中为 55.6%（均 p＜0.0001）。多变量逻辑回归分析显示，ADC 比值（p=0.03；比值比，0.12）和动态 CT 增强模式（p=0.04；比值比，16.21）是鉴别高信号 HCC 与 FNH 的独立因素。
对于诊断从 FNH 和 FNH 样结节中区分出的高信号 HCC，动态 CT 的动脉期增强和洗脱模式以及 ADC 比值的降低可能是重要的发现。
