正常犬肺动脉三维CT重建中不同剂量对比剂的比较

背景：行CT血管成像时,需要静脉注入碘对比剂,并且随着对比剂应用剂量的增大,对患者带来的危害也相应增大。 目的：验证低剂量对比剂在多层螺旋CT肺动脉成像中的可行性。 方法：12只健康家犬参照临床上人的碘海醇(300 mgI/mL)使用剂量,根据《药理实验中动物间和动物与人体间的等效剂量换算》得出相应犬的3个剂量组分别为碘海醇2.40 mL/kg,2.02 mL/kg,1.62 mL/kg组。12只犬分别接受3种剂量各1次,每次实验扫描间隔时间至少48 h,共进行36次CT扫描。根据原始图像、容积重现像和最大密度投影像,对3种方案肺动脉分支的显示情况、肺动脉边缘清晰程度及肺静脉充盈程度进行评分,并测量肺动脉内对比剂的浓度。 结果与结论：3种方案均能清晰显示犬肺动脉4级分支,血管边缘清晰,显示程度评分各组差异无显著性意义(P > 0.05)。3种方案肺静脉显影程度均较低,与肺动脉有很好的密度对比,各组差异无显著性意义(P > 0.05)。3种方案肺动脉内的对比剂浓度均维持在较高的水平,差异无显著性意义(P > 0.05)。提示低剂量对比剂在多层螺旋CT犬肺动脉成像中是可行的,图像质量可以满足临床诊断要求,从而为临床应用低剂量对比剂行肺动脉成像提供实验依据。

Comparison of different dose contrast media in three-dimensional CT reconstruction of healthy canine pulmonary artery

BACKGROUND:CT angiograph needs that the contrast media injects into vein, and the greater the dose of contrast media, the greater the hazard to patients. OBJECTIVE:To validate the feasibility of low dose contrast media in spiral CT pulmonary artery angiograph.  METHODS:A total of 12 healthy canis familiaris with reference to iohexol dose of human in clinic, according to “equivalent dose conversion of animals and between animals and humans in pharmacological experiments”, which got the corresponding three dose groups: iohexol 2.40 mL/kg group, iohexol 2.02 mL/kg group, iohexol 1.62 mL/kg group. Twelve canis familiaris were treated with 3 kinds of doses for once; scan interval of each experiment was at least 48 hours, a total of 36 CT scans. Pulmonary artery branch conditions, pulmonary vein edge clarity, and filling degree of pulmonary vein of 3 proposals were scored by original image, volume recurrence image, and maximum intensity projection image, and the concentration of contrast media in pulmonary artery was measured RESULTS AND CONCLUSION:Three kinds of proposals can clearly show 4 branches of canines’ pulmonary artery, the edge of vascular is clear. There was no significant difference in each group (P > 0.05). The degree of pulmonary vein imaging was lowered, and had a good density comparison with pulmonary artery; there was no significant difference in each group (P > 0.05). The concentration of contrast media in pulmonary artery maintained at a high level, there was no significant difference (P> 0.05). It is indicated that it is feasible to use low dose contrast media in multislice spiral CT pulmonary artery angiograph of canines, the image quality can meet the clinical diagnostic requirements to provide the experimental basis of pulmonary artery angiograph with low dose contrast media for clinical application.