肝转移瘤螺旋CT多期扫描

Multiphase helical CT scanning of hepatic metastases

目的分析肝转移瘤(HMs)螺旋CT多期扫描表现,探讨适合HMs诊断、鉴别诊断及检出的螺旋CT最佳扫描计划。方法收集原发灶明确、并经临床、CT证实的HM46例,所有病例均作了螺旋CT平扫和动脉期、门脉期、平衡期增强扫描,5例尚作了延迟扫描。至少两位医师阅片,分析记录HMs螺旋CT多期表现。结果平扫多数瘤灶(69.6%)呈外周略低密度中央更低密度。多期增强扫描,第1类少血供37例(80.4%),以门脉期明显环形强化为主;第二类富血供6例(13.0%),以动脉期明显环形强化为主;第三类无血供3例(6.6%),动脉期、门脉期、平衡期均无强化。结论对有特征性的少血供或无血供HMs仅需门脉期单期扫描;而对富血供者,则需作多期扫描,以便与其它富血供的肝脏病变鉴别。

Objective To analyze the different appearances of multiphase helical CT scanning o f hepatic metastases(HMs )and to in-vestigate the optimal scanning plan for diagnosing and detecting HMs.Methods Forty -six patients with HMs those pr imary cancers were proved by clinical and imaging data u nderwent CT plain scans and arterial ,portal,and equilibrium phase enhanced scan s.5patients un-derwent additional delayed scans.Resutls Most HMs (69.6%)were revealed central lower attenuation surrounded by low attenuation r im on plain scans.According to the blood -supply of HMs during multiphase scan s,all of HMs were classified info thr ee categories,i.e.hypovasular(80.4%),hypervascular(13.0%),and nonvascular(6.6%)metastases.Hypovascular HMs showe d a thickened ring of enhancement during the portal phase,hypervascular HMs Showed a complet e ring of enhancement during the arte rial phase.and nonvascular HMs showed non -enhancement during a ll of phases.Conclusion Most typical hypo -or nonvascular HM s need only to perform the portal phase scan while hypervascular HMs n eed to perform the multiphase scans s o as to differentiate them from other hrpervascular lesions.[