多层螺旋CT对微小肝癌的诊断研究

Diagnosis of microhepatic cellular carcinoma with multi-slice helical computed tomography

目的研究多层螺旋CT(MSCT)多时相薄层扫描对微小肝癌(MHCC)的诊断价值,提高MH-CC的检出率。方法选择临床上已确诊为肝功能失代偿期的肝硬化患者300例,先行常规螺旋CT增强扫描后,然后行MSCT多时相薄层扫描,即动脉期(20～25 s)、门静脉期(50～55 s)、平衡期(2～3min),高压注射器灌注非离子型对比剂为3 mL/s,扫描层厚3～5 mm,螺距(pitch)为1。CT检查阳性病例均在DSA上行选择性肝动脉造影检查,并与常规螺旋CT增强检查结果对比。结果 300例肝功能失代偿期肝硬化患者中共检出MHCC 27例,MHCC的MSCT表现特点是平扫呈等密度或略低密度,多时相薄层增强扫描图像表现:动脉期呈高密度,门静脉期呈略高密度、等密度或略低密度,平衡期呈等密度或低密度。三期敏感性分别为:动脉期92.59%,门静脉期77.78%,平衡期88.89%,综合多时相薄层扫描敏感性为96.30%,DSA上检出MHCC的描敏感性为33.33%。而常规螺旋CT增强扫描结果为:动脉期40.40%,门静脉期26.67%,平衡期33.33%,综合三期敏感性为53.33%。结论 MSCT多时相薄层扫描诊断MHCC是临床上必须选择的最佳检查方法,检出MHCC癌灶以动脉期和平衡期为最佳,综合多时相薄层扫描影像明显提高MHCC的检出率和诊断正确率。

Objective To study diagnostic value of microhepatic cellular carcinoma（MHCC） with multi-slice helical computed tomography（MSCT） for increasing detection rate.Methods Three hundred patients with cirrhosis of liver were diagnosed by clinical,and underwent regularly multi-phase helical CT with 3~5 mm thick-section scan.For multi-phase helical CT,hepatic arterial-phase（HAP） and portal venous-phase（PVP） and delayed-phase（DP） scanning began 20~25 s,55~55 s,2~3 min,respectively,after intravenous nonionic contrast material injection at a rate of 3 mL/s.DSA was performed in 25 patients of which MHCC was detected by CT,and compared with CT.Results There were 27 MHCC patients in 300 cases.The CT characteristics of micro-nodules were iso-and hypodense in unenhanced scan,all hyperdense in HAP,iso-and hypodense in PVP,iso-and hypodense in DP.The sensitivity was 93.5% at HAP,86.5% at PVP,90% at DP,and 80.5 in DSA.The sensitivity was 40.4% at HAP,26.67% at PVP,33.33% at DP in CT.Conclusion MSCT scanning is the bestmethod in detecting MHCC.However,some nodules are detected only with the HAP and DP images.Therefore,all three phase scan are recommended for detection of MHCC.