肝局灶性结节增生的MRI诊断价值与CT征象比较

目的:评价肝局灶性结节增生(FNH)的MRI诊断价值。方法:经手术或穿刺活检病理证实的FNH19例,共21个病灶。全部病例进行了CT和MRI检查,CT检查常规行平扫和双期增强扫描;MRI平扫序列如下:用快速恢复快速自旋回波序列(FRFSE)采集压脂T2W图像,用快速扰相梯度回波序列(FSPGR)采集压脂T1W图像,用真稳态进动梯度回波序列(FIESTA)采集T2/T1比值加权图像,用FSPGR序列同时采集无脂肪抑制的反相位和同相位T1W图像。所有病例均行Gd-DTPA动态增强扫描,其中3例进行细胞特异性对比增强扫描。结果:17个FNH在平扫T2WI fs为等信号或略高信号,在T1WI fs上呈等信号或略低信号。MRI平扫共见中心瘢痕12个、中央粗大血管3条、假包膜数2个,均多于CT平扫所见。Gd-DTPA动态增强扫描时,21个FNH于动脉期均明显强化,16个FNH于门脉期或延迟期的信号强度与肝组织接近,中心瘢痕和假包膜延迟强化。行细胞特异性对比增强扫描的3个FNH实质均明显强化,中心瘢痕无强化。结论:绝大多数FNH在MRI上有特征性的征象,MRI可以明确诊断,MRI对FNH的诊断价值高于CT。

Focal nodular hyperplasia of the liver: the value of MRI and CT diagnosis

Objective:To investigate the value of MR imaging in diagnosis of focal nodular hyperplasia(FNH) of the liver.Methods:19 cases with FNH(total 21 lesions) proved pathologically examined by CT and MRI.Non-contrast enhanced and dynamic contrast enhanced scanning were performed on 19 patients.Cell specific contrast-enhanced scanning was performed on 3 cases.The finding of CT and MRI of FNH were analysed and compared.Results:Of 21 FNH on non-enhanced scanning,17 FNH manifested isointensity or lightly hypointensity on T1WI and lightly hyperintensity on T2WI.12 central scars and 3 thicken central vessel and 3 pseudocapsule of FNH were found on non-contrast enhanced MRI,more than on non-contrast enhanced CT.21 FNH had obvious enhancement during arterial phase,and 16 FNH signal intensity were becoming to near the liver during portal phase or delayed phase.The central scar and pseudocapsule were enhanced during late portal phase and delayed phase.On cell specific contrast-enhanced scanning,the parenchymal of FNH were markedly enhanced on 3 cases,whereas the central scar were not enhanced,becoming more clear.Conclusion:Most FNH having characteristic findings on MRI,can be correctly diagnosed.To FNH,the value of MRI diagnosis is higher than CT.