螺旋CT双期或三期扫描对肝脏占位性病变的诊断

Diagnosis of hepatic space-occuping lesions with spiral CT two- phase or three phase scans

目的分析肝脏螺旋CT双期或三期扫描表现,探讨其对原发性肝癌、肝转移瘤、肝血管瘤的诊断及鉴别诊断的意义。方法经临床证实25例,均作螺旋CT平扫、动脉期、门脉期及部分平衡期和延迟期扫描,并分析螺旋CT多期扫描表现。结果原发性肝癌动脉期明显强化而肝脏无强化,形成鲜明的对比。门脉期呈相对低密度或恢复到平扫时表现。肝血管瘤CT特征为动脉期呈边缘性环状、结节样强化,门脉期病灶边缘强化向中心强化并充满病灶呈高密度,平衡期呈等密度或低密度。肝转移瘤表现多样化,周边强化或不均匀强化或不强化。结论螺旋CT双期或三期扫描已作为对肝脏占位性病变的主要检查方法,并作为常规。

Objective To analyze CT findings of hepatic space- occuping lesions during arterial phase,portal venous phase and delayed phase scans and to test the dynamic CT capability to differentiate the primary hepatocelluar carcinoma(HCC) from hemangioma and metastasis.Methods Twenty- five patients with clinically proved hepatic spacc- occuping lesions in which included HCCs(15),hemangiomas(5),and metastases (5) underwent spiral CT precontrast scans and dynamic arterial phase and portal venous phase scans,5 patients with hemangioma underwent additional delayed phase scans.Results In arterial phasc,HCC appeared as obvious enhancement while the liver was non- enhanced so that formed a clear contrast between the lesions and normal tissue.In portal venous phase,HCC presented relative hypodense or recovered to precontrast findings.Hepatic hemangioma was characterized by circular or nodular enhancement of borders in arteral phase and step by step enhanced from border to center in portal venous phase and appeared as hyperdense while in delayed phase the lesions were totally isodense or hypodense.CT findings of liver metastases were varied such as the borders to be enhanced or non homogeneous enhanced or non enhanced.Conclusion The contrast enhancement patterns of HCCs,hemangiomas and metastases seen in dynamic CT scanning are useful in the differential diagnosis of these tumors. [