Indocyanine green (ICG) excretory defect is characterized by an ICG retention rate of more than 50% at 15 min without any other abnormal liver functions. The incidence of ICG excretory defect is 0.007% in the Japanese population. Due to its rarity, the imaging characteristics associated with ICG excretory defect remain unclear. Herein, we present three cases of ICG excretory defect, which showed impaired lesion detectability on gadoxetic acid-enhanced MR imaging (EOB-MRI). In the hepatobiliary phase (HBP) of EOB-MRI, diminished enhancement of the liver parenchyma, prolonged intravascular enhancement, and attenuated gadoxetic acid excretion to the bile duct were observed. Our study also investigated the expression level of organic anion transporting polypeptide (OATP) 1B3 and OATP1B1/1B3, which is related to the uptake of ICG and gadoxetic acid into hepatocytes. All cases showed decreased expression of OATP1B3, which was assumed to be characteristic of ICG excretory defect. The present study indicates that, when patients with ICG excretory defect are evaluated using EOB-MRI, attention should be paid to the impaired lesion detectability in the HBP due to the attenuated gadoxetic acid uptake into the liver parenchyma.

吲哚菁绿 (ICG) 排泄缺陷的特点是 15 分钟时 ICG 保留率超过 50%，没有任何其他肝功能异常。日本人群中ICG排泄缺陷的发生率为0.007%。由于其罕见，与 ICG 排泄缺陷相关的成像特征尚不清楚。在此，我们介绍了三例 ICG 排泄缺陷病例，其在钆塞酸增强 MR 成像 (EOB-MRI) 上显示病变可检测性受损。在 EOB-MRI 的肝胆期 (HBP) 中，观察到肝实质增强减弱、血管内增强延长和胆管中的钆塞酸排泄减弱。我们的研究还调查了有机阴离子转运多肽 (OATP) 1B3 和 OATP1B1/1B3 的表达水平，这与 ICG 和钆塞酸进入肝细胞有关。所有病例均显示 OATP1B3 表达降低，这被认为是 ICG 排泄缺陷的特征。目前的研究表明，当使用 EOB-MRI 评估 ICG 排泄缺陷患者时，应注意 HBP 中由于减弱的钆酸摄取到肝实质而受损的病变可检测性。