双源CT“双低”冠脉成像应用的可行性研究

The study of the feasibility of dual-source CT and “double low”coronary artery imaging

目的探讨双源CT低管电压和低浓度造影剂冠脉成像在正常体质量患者中的应用可行性。方法连续选择60例体质量指数(BMI)<24 kg·m-2、心率<80次/分的患者,将其分为两组,每组30例。A组使用370 mg I·m L-1造影剂和100 Kv管电压回顾性冠脉扫描,B组使用320 mg I·m L-1造影剂和80 Kv管电压前瞻性冠脉扫描。分别测量两组图像主动脉根部CT值、图像噪声、信号噪声比(SNR)和对比噪声比(CNR),使用双盲法对冠脉图像质量以4分法进行评分,对两组图像质量评分进行比较。结果 A组主动脉根部CT值、噪声低于B组,SNR和CNR高于B组,均差异有统计学意义(均P<0.05);主观评价两组图像质量差异无统计学意义;B组有效辐射剂量(1.60±0.41)m Sev明显低于A组(4.15±0.52)m Sev,差异有统计学意义(P<0.05),碘摄入量B组明显低于A组。结论对于BMI<24 kg·m-2、心率<80次/分的患者,采取"双低"扫描方案,在保证图像质量的同时,患者接受有效辐射剂量和碘摄入量大大降低。

Objective To discuss the feasibility of Dual-source CT tube of low voltage and low concentration contrast applied in coronary artery imaging in patients with normal body weight. Methods 60 patients with BMI 24 kg·m-2,heart rate 80 times/min were selected consecutively and divided into two groups,with 30 cases in each group： group A with 370 mg I·m L-1 contrast agents and 100 Kv voltage retrospective coronary scanning,group B using 320 mg I·m L-1 contrast agents and 80 kv voltage prospective coronary scanning. The aortic root image CT value and image noise,SNR and CNR,were measured in the two groups using double blind method in coronary artery image quality rating method with four points,two groups of image quality score were compared. Results The CT values of the aortic root,noise of group A were lower than that of group B,SNR and CNR of group A were higher than that of group B,there were statistically significant（respectively P〈0. 05）. Subjective assessment of the difference in image quality between the two groups is not significant. The effective radiation dose（1. 60 ± 0. 41） m Sev in group B was significantly lower than that in group A（4. 15 ± 0. 52）m Sev,and the difference was statistically significant（P〈0. 05）. Iodine intake in group B was significantly lower than in group A. Conclusion With the application of＂double low＂scan,the patients with BMI 24 kg·m-2,heart rate 80 times/min received less radiation dose and iodine intake while the quality of the image was not affected.