新型磁共振造影剂钆贝葡胺诊断肝细胞癌的价值及病理基础

Value of Gd-BOPTA Enhanced MR in Diagnosing Hepatocellular Carcinoma with Correlation of Pathology

目的探讨具有双相增强作用的磁共振造影剂钆贝葡胺(gadobenate dimeglumine,Gd-BOPTA)诊断肝细胞癌(HCC)的价值及其MR表现的病理基础。方法33例(42个病灶)CT或超声检查疑有肝脏占位的患者,按以下顺序接受MRI常规轴位的T2WI和T1WI平扫、冠状的T2WI、3D磁共振胆胰管成像(MRCP)、Gd-BOPTA增强的轴位LAVA三期动态扫描(延时时间为15、55及90s)、2D-T1W增强扫描、LAVA延时扫描(5及10min)和肝胆期扫描(20、40及80min)。收集大体标本及病理切片,与磁共振表现进行对比分析。结果手术病理证实HCC诊断21例(27个结节)。包含动态期和肝胆期在内的综合MRI诊断HCC的敏感性、特异性及准确性分别为92.9%、93.3%和92.9%。①血液动力学期(动态及延迟期):HCC以“快进快出”强化表现为主(22个),少数呈动静脉期强化(4个)及均无强化(1个)。②肝胆期(排泄期):23个HCC结节呈均匀稍低信号;另外4个结节(3个高分化及1个中分化)呈非均匀稍低信号,其中散在云絮状或斑点状稍高信号,病理上见肿瘤细胞淤胆及含有胆汁的毛细胆管存在。结论双相作用的Gd-BOPTA增强MR检查既能反映HCC的血供特点,又能反映病灶内不同程度丢失正常肝细胞功能的病理基础,具有较好的诊断价值。

Objective To investigate the value of new double-phasic MR contrast agent （gadobenate dimeglumine, Gd-BOPTA） in diagnosis of hepatocellular carcinoma （HCC） with correlation of pathology. Methods MRI scan was performed on 33 patients suspected of having focal liver lesions by CT or ultrasonography. The MRI scan protocol included routine axial T1WI and T2WI, coronal T2WI and 3D-MRCP, Gd-BOPTA enhanced 3D gradientecho sequence of T1W （LAVA sequence） acquiring dynamic data at 15 s, 55 s and 90 s respectively, delayed LAVA acquisition at 5 min, 10 min, and at 40 min, 80 min respectively. Surgical specimen was collected for pathological analysis. Results Surgery confirmed the diagnosis of HCC in 21 patients with 27 lesions. The sensitivity, specificity and accuracy of MR imaging with combined phases （including hemodynamic phase and hepatobiliary phase） were 92.9%, 93.3%, 92.9% respectively. （1）In the hemodynamic phase： 22 lesions showed early enhancement in arterial phase, fast ＂washout＂ in portal venous phase, and hypointense in delayed phase. Four lesions showed slight enhancement, while 1 lesion showed no enhancement in all hemodynamic phases. （2）in the hepatobiliary phase： 23 le sions showed homogeneous hypointensity compared to the enhanced liver background, but 4 lesions （3 well-differentiated and 1 moderately-differentiated） had patchy or dot-like slightly hyperintense areas scattered within the lesions. Pathologically cholestatic changes of tumor cells were observed and bile-contalning small ducts were present. Conclusion Gd-BOPTA enhanced MRI can both depict the hemodynamic characteristics and reflect the absence of normal hepatocyte function in HCC lesions, thus contributing greatly to the diagnosis of HCC.