肝局灶性结节增生的多种影像学表现分析

目的分析肝局灶性结节增生(FNH)的CT、DSA及18FDG正电子发射体层摄影术(PET)的影像表现,认识FNH的多种影像学特征.资料与方法 10例FNH经手术病理证实,回顾分析其多种影像学表现.10例均行CT平扫及动态增强扫描,其中4例行DSA肝动脉造影,2例行18FDG PET显像.结果 10例FNH均为单发性结节,位于肝右叶8例,肝左叶2例.肿瘤直径1.1～9.3 cm,平均5.1 cm.CT检查10例,平扫均为低密度,其中8例病灶(直径均＞3.0 cm)中央区有星芒状的更低密度区;增强扫描,动脉期9个结节明显强化,1个中等强化,病灶中央更低密度区无强化,2个病灶中央或周边见增粗迂曲血管,其中1个尚可见动脉-门脉、动脉-静脉分流现象;门脉期病灶密度稍有下降,8个高于或等于肝实质,2个低于肝实质;延迟期7个等于或略高于肝实质,3个低于肝实质,5个病灶中央更低密度有强化.血管造影:4例FNH的供血动脉均来自肝动脉系统,供血动脉增粗、扭曲, 1例血管分支放射状分布,周围呈环绕状聚集染色,中央局限性缺损,另3个分支血管紊乱并呈抱球征,1个尚见动脉-门脉、动脉-静脉分流.2例18FDG PET显像均未见异常放射性浓聚.结论 FNH CT平扫为低密度,增强扫描以"快进慢出"为主要特征,而血管造影显示肝动脉供血为主,表现为供血动脉增粗、扭曲,呈轮辐状向周围发散.这些影像特征有利于FNH的定性诊断.

Analysis of Different Imagings Findings in the Hepatic Focal Nodular Hyperplasia

Objective To analyse CT, DSA and PET appearances of focal nodular hyperplasia (FNH) of the liver, and realize the typical and atypical characteristics.Materials and Methods 10 patients with FNH proved surgically and pathologically were performed with Pre and postcontrast CT scan. Transcatherter arterial angiography was performed in 4 patients, and FDG PET examination in 2 patients. CT, DSA and PET appearances of focal nodular hyperplasia (FNH) of the liver were reviewed retrospectively.Results All FNH were solitary lesions. 10 lesions were all hypodense on plain CT scan. 8 of 10 lesions were shown punctate, streak and radial scar with even lower hypodense. On the arterial phase scans, marked and homogenous enhance were seen in all but one lesion which was moderate enhanced without enhancement of the central scar. 2 of 10 were shown dilated and tortuous arteries at the center or peripheral area, and one with shunt of artery-portal vein and artery-vein. On the portal venous phase scans, focal density were decreased, but still showing hyperdense or isodense relative to normal liver in 8 lesions. On the delay phase scans, 7 of 10 lesions were slightly hyperdense or isodense, 3 of 10 were hypodense. Enhancement of central scar were observed in 5 lesions. On the angiography images, dilated feeding arteries were seen in all the 4 patients. 1 patient was shown radiate arterial branches which stain at the peripheral area, and absent stain at the central area. The other 3 were presented disorderly arterial branches and global stain. 1 of 3 were shown hepatic arteriovenous shunt and arterio-portal venous shunt. 18 FDG PET imaging were performed in 2 of 10 patients without abnormal concentration.Conclusion FNH is presented hypodense on pre-contrast CT scan, and obvious enhancement in the early arterial phase, and enhancement of the central scar in delay phase. On the angiography imaging, feeding arteries of FNH is presented as radical vascular architecture which arise from hepatic artery, these characteristics of different imagings are useful for diagnosing FNH of the liver.