延迟期CT动态增强扫描对肝脏占位病变的术前评估价值

Value of delayed-phase dynamic CT enhancement in preoperative evaluation for focal liver lesions

目的:通过对肝脏双期与三期增强扫描进行对比,探讨动态增强CT延迟期对肝脏占位病变术前评估的价值。方法:选取我院因发现肝脏占位性病变拟行手术切除治疗的患者34例,行CT三期动态增强检查(动脉期、门静脉期及延迟期扫描时间分别为注药后30、70及180s),对病变进行定性诊断及术前评估。由两位具有15年以上肝脏影像诊断经验的医师对图像进行两次评价,第一次仅评价动脉期及门静脉期图像,第二次评价全部三期增强图像,评价内容包括病变显示清晰程度、血管显示能力(肝动脉、门静脉、肝静脉)、影像诊断及诊断信心。结果:两位医师对于病变显示清晰程度、良恶性诊断及诊断信心的主观评价,两次阅片比较差异均无统计学意义(P>0.05)。A、B两位医师第一次阅片诊断符合率分别为82%(28/34)和79%(27/34),第二次阅片分别为85%(29/34)和88%(30/34)。B医师对于肝静脉显示两次阅片评价结果差异具有统计学意义(P=0.005)。结论:与肝脏CT双期增强扫描比较,三期增强扫描(增加延迟期)在肝脏占位性病变的术前评估中对病变范围的显示、肝脏术前血管的评估及医师诊断信心方面并没有明显作用,但增加了辐射剂量;但三期增强扫描一定程度上增加了肝脏占位病变的定性诊断准确性。

Objective：To study the value of delayed-phase of dynamic CT enhancement in preoperative evaluation for focal liver lesions by comparing dual-phase with triple-phase CT scan. Methods..Thirty-four patients （from January 2012 to December 2012） with focal liver lesions undergoing dynamic triple-phase CT scan were included in this study. All the patients underwent surgical resection. In triple-phase CT,hepatic arterial,portal venous and delayed phase scanning began 30, 70 and 180s,respectively,after the injection of 100 ml of iodinated contrast material （injecting rate 4ml/s）. Dual-phase images excluding delayed-phase and triple-phase CT images were reviewed independently by two experienced radiologists. The subjective evaluation included border of lesion, benignancy or malignancy, diagnosis and confidence. The vascular display ability （including hepatic artery, portal vein and hepatic vein） was also assessed. Results： The diagnosis coincidence rate of two radiologists were 82% （28/34） and 79% （27/34） for dual-phase reading,and 85% （29/34） and 88% （30/34） for triple-phase reading, respectively. Border of lesion, benignancy or malignancy evaluation and diagnosis confidence had no statistical significance between two readings （P〉0.05）. The evaluation of doctor B for hepatic vein display ability had statistical significance between two readings （P = 0. 005）. Conclusion： Compared with dual-phase, triple-phase liver CT scan （including delayed-phase） has higher radiation dose meanwhile can provide more diagnostic information, which can properly inerease diagnostic accuracy of focal liver lesion; however, it has no additional value for the preoperative evaluation including extent of lesion and vascular display.