肝内结节性病变MRI信号改变与血供的关系

Relationship between MRI Signal Intensity and Blood Supply in Hepatic Nodule Lesions

【目的】以肝硬化基础上发生的再生性结节(RN)、增生性结节(DN)、小肝癌(SHCC)的MRI信号表现推断病灶的血供特点,分析病灶血供与信号变化的对应关系。【方法】对经病理证实的17个DN、16个RN和45个SHCC病灶进行回顾性分析,观察病灶的大小、信号强度、强化的方式和时间,推断病灶的血供特点,分析病灶血供与信号变化的关系。【结果】RN为T1WI高、T2WI低的信号,动态增强为缓慢上升型,提示动脉、门脉血供均少;DN在T1WI高、中、低信号均有,T2WI为等信号和稍高信号,动态增强为速升缓降型,提示动脉供血增多、门脉正常;SHCC以T1WI低、T2WI高信号为主,动态增强为速升速降型,提示动脉血供增多、门脉减少。由RN到SHCC,相应的T1WI和T2WI信号高低之间有统计学差异(P<0.05)。【结论】从RN到SHCC,动脉血供逐渐增多,门脉血供逐渐减少,T2WI信号由低转高,T1WI由高转低,血供与信号之间有一定的对应关系。

[Objectives] To investigate the characteristics of blood supply based on the magnetic resonance imaging （MRI） signal manifestations of regenerative nodules （RN）, dysplastic nodules （DN）, and small hepatocellular carcinoma （SHCC） secondary to liver cirrhosis, and to evaluate the corresponding relationship between blood supply and MRI signal intensity of hepatic nodules. [Methods] The MR imaging of 17 RNs, 16 DNs and 45 SHCCs, which had been confirmed by pathology, were analyzed retrospectively. The size of the focus, signal intensity, dynamic enhancement patterns and phases were observed to investigate the characteristics of blood supply and to analyze the relationship between blood supply and the change of signal intensity. [ Results] Most RNs demonstrated super intense signal on T1WI and hypo-intensity on T2WI. The slow sustained enhancement indicated the decreasing blood supply of artery and portal vein. DNs showed high, low or iso-intensity on T1WI and isoor high intensity on T2WI with speedy rising and slowly decreasing dynamic enhancement which indicated the increasing blood supply of artery and normal supply of portal vein. SHCCs showed hypointensity in most cases on T1WI, and hyper-intensity on T2WI. Dynamic enhancement increased and decreased rapidly which indicated that the artery blood supply increased and the portal venous supply decreased. There were statistically significant differences in signal intensity on T1WI and T2WI between RN, DN, and SHCC （P 〈 0.05）. [Conclusions] From RN to SHCC, arterial supply increased gradually and portal venous supply decreased gradually as well. The signals change from hypo- to hyperintensity on T2WI, and from hyper- to hypo- intensity on TIWI. There exists a definite corresponding relationship between the blood supply and the signal.