MR和CT动态扫描对小肝癌强化特征的比较研究

目的 前瞻性比较研究小肝癌（SHCC）在动态MR和螺旋CT多期扫描中的强化特征,探讨MR优于螺旋CT的原因。方法 53例SHCC患者，均行螺旋CT和MR动态增强扫描。螺旋CT全肝平扫后分别行动脉期、门脉期和延迟期的增强扫描。MR和SE序列和FMPSPGR序列动态增强多期扫描。结果 53例患者共发现病灶76个，MR和CT动脉期扫描分别有69个病灶和49个病 灶有明显强化。SHCC在MR和CT动脉期－门脉期－延迟期扫描中的典型表现为高－低－低信号（密度）和高－等－低信号（密度）；不典型的表现为高－高－高信号（密度）、高－等－等信号（密度）和低－低－低信号（密度）。结论 动态MR和螺旋CT多期扫描均可显示SHCC的强化特征。MR动脉期扫描更能充分反映SHCC富血供的特点；在定性诊断方面，结合SE序列上的一些信号特征，MR更优于螺旋CT。

Comparason of enhancement patterns of multi-phase scan of dynamic MRI and dynamic CT in small hepatocellular carcinoma

Objective To study prospectively the enhancement features of multi phase scan of dynamic MRI and spiral CT in the diagnosis of small hepatocellular carcinoma(SHCC) and to discuss the cause of dynamic MRI being superior to spiral CT.Methods Multi phase contrast scanning of dynamic MR and spiral CT were done in 53 SHCC patients. The lesions were proved by surgery and pathology. The arterial phase, portal venous phase and delayed phase scan of spiral CT were carried out after the pre contrast scanning of the entire liver. MRI was performed with SE sequence and FMPSPGR sequence dynamic multi phase contrast scans.Results Seventy six lesions were found in 53 patients. Sixty nine lesions and 54 lesions were enhanced obviously in MR and spiral CT arterial phase scans. The typical enhancement patterns of SHCC in the arterial phase, portal venous phase and delayed phase scan of MRI and spiral CT were hyper hypo hypointense (dense) and hyperintense (hyperdense), isointense (isodense) and hypointense (hypodense). Atypical enhancement patterns were hyperintense (hyperdense), hyperintense (hyperdense), hyperintense (hyperdense), hyperintense (hyperdense), isointense (isodense), isointense (isodense) and hypointense (hypodense), hypointense (hypodense) and hypointense (hypodense).Conclusion Both dynamic MRI and spiral CT multi phase contrast scanning are able to demonstrate the enhancement features of SHCC, with arterial phase scan of MRI being superior to spiral CT in reflecting the hypervascular characterization of SHCC. Combined with SE sequence in characterizing the SHCC, MRI is better than spiral CT.