双低能谱CT对活体供肾动脉的术前评估

Application of Gemstone CT with Low Tube Voltage and Low Dosage Contrast Medium in Evaluating Preoperative Living Donor Renal Artery

目的探讨采用宝石能谱CT低剂量对比剂、低管电压技术肾动脉成像在肾移植供体术前评估中的应用价值。资料与方法对50例活体供肾者于肾移植术前行螺旋CT肾动脉成像,将其随机分为双低组和对照组,每组25例。双低组管电压100 k V,对比剂使用威视派克(270 mg/ml);对照组管电压120 k V,对比剂使用碘普罗胺(370 mg/ml)。两组图像的重建均为40%ASi R,其他扫描参数不变。比较两组图像质量评分、肾动脉CT值、对比噪声比(CNR)、噪声、辐射剂量以及对比剂用量。结果 2名医师对两组肾动脉图像质量评分的一致性较高(Kappa=0.82)。两组的肾动脉CT值、图像质量整体评分及细节评分比较,差异无统计学意义(t=1.05、0.07、1.62,P>0.05);两组CNR、噪声及辐射剂量比较,差异有统计学意义(t=2.92、-6.95、-2.21,P<0.05);双低组的对比剂用量较对照组降低了27%。结论低浓度对比剂(270 mg/ml)联合低管电压(100 k V)及迭代重建算法在肾动脉CTA中可获得满意的图像,可作为活体肾移植供体术前检查的常规方法。

Purpose To explore the gemstone CT with low tube voltage and low concentration contrast medium in evaluating renal artery imaging of preoperative living renal transplantation donor. Materials and Methods Fifty cases of living kidney donor underwent spiral CT angiography of renal artery before operation. The patients were randomly divided into double-low group（25 patients） with 100 k V and Visipaque（270 mg/ml）, and control group（25 patients） with 120 k V and Iopromide（370 mg/ml）. Image reconstruction of 40% ASi R was used in both groups. The image quality score, CT values of renal arteries, contrast-to-noise ratio（CNR）, noise, radiation dose and the amount of contrast agent of the two groups were recorded and compared. Results Kappa coefficient analysis showed that the consistency in evaluating image quality between two radiologists was excellent（Kappa=0.82）. The CT value of the renal arteries and image quality did not show significant difference between the two groups（t=1.05, 0.07 and 1.62, P〈0.05）. The CNR, noise and average radiation dose were statistical different between the two groups（t=2.92,- 6.95 and- 2.21, P〈0.05）. The contrast medium dosage of double-low group was decreased by 27% when compared with that of the control group. Conclusion Satisfied image quality of renal artery CTA can be obtained with low tube voltage（100 k V） and low concentration contrast medium（270 mg/ml） combined with iterative reconstruction algorithm. It can be used as a routine method in preoperative examination of living renal donors.