肝转移瘤的CT灌注成像

目的探讨肝脏CT灌注成像对肝转移瘤诊断及鉴别诊断的应用价值。方法对28例肝转移瘤患者进行CT灌注成像;根据其表现特征,采用校正后的最大斜率法计算各自的灌注参数;应用改进后的图像重建方法重建出肝转移瘤的4种灌注图像。结果富血供转移瘤的时间-密度曲线(TDC)呈速升速降型或速升缓降型,肝动脉灌注量(HAP)明显增加,门静脉灌注量(PVP)明显减低,与周围肝实质相比呈明显HAP、PVP倒置倾向,肝动脉灌注指数(HPI)明显升高,门静脉灌注指数(PPI)明显降低。在HAP图像上,癌灶呈明显高灌注,周围肝实质呈低灌注;在PVP图像上,癌灶呈明显低灌注,周围肝实质呈高灌注;在HPI、PPI图像上的表现分别类似HAP、PVP。乏血供转移瘤的TDC呈缓慢上升型,其基线、上升斜率及上升幅度均明显低于周围肝实质,其全肝总灌注量(TLP)、PVP和PPI均明显低于周围肝实质,HPI略高于周围肝实质。在HAP图像上,癌灶呈不均匀低灌注,周围肝实质呈相对较高灌注;在PVP图像上,癌灶仍呈低灌注,周围肝实质呈不均匀高灌注,病灶轮廓更清晰;在HPI和PPI图像上的表现分别与HAP、PVP类似。结论肝脏CT灌注成像能在一次扫描过程中同时获得良好显示解剖细节及灌注定量信息的影像学资料,准确地反映肝转移瘤的血液动力学特征,有利于病变的定性诊断,具有重要的临床应用价值。

CT Perfusion Imaging of Hepatic Metastases

Objective To explore the applied value of CT perfusion imaging in diagnosis and differential diagnosis of hepatic metastases.Methods CT perfusion was performed in 28 patients with hepatic metastases,the perfusion parameters were calculated by maximum slope method,four kinds of perfusion images were reconstructed by modified-reconstruction method.Results In the hypervascular metastases,the time-density curve(TDC) was quickly risen and fallen or quickly risen and slowly fallen,hepatic arterial perfusion(HAP)obviously increased,portal venous perfusion(PVP) obviously decreased,and the value of HAP,PVP was reversed compared with that of hepatic parenchyma,hepatic arterial perfusion index(HPI) obviously increased,portal venous perfusion index(PPI) obviously decreased.The hypervascular metastases appeared as high perfusion on HAP images,but as low perfusion on PVP images,the hepatic parenchyma appeared as low perfusion on the HAP images and high perfusion on the PVP images.Appearance of all of them at the HPI images and the PPI images was similar to that on the HAP images and the PVP images respectively.In the hypovascular metastases,TDC was slowly risen,the base-line,the risen slope and its amplitude were very lower than that of hepatic parenchyma,total liver perfusion(TLP),PVP and PPI in the hypovascular metastases were obviously lower than that of hepatic parenchyma,HPI was slightly higher.The hypovascular metastases appeared as heterogeneously low perfusion on the HAP images and also as low perfusion on the PVP images,the hepatic parenchyma appeared as relatively high perfusion on the HAP images and as heterogeneously high perfusion on the PVP images.Appearance of all of them at the HIP images and the PPI images was similar to that on the HAP images and the PVP images respectively.Conclusion CT perfusion can accurately reflect the hemodynamic change of hepatic metastases,it's very useful in diagnosis of hepatic metastases,so it has very important clinical applied value.