探讨超低剂量前瞻性冠脉CTA成像技术在低体重指数患者中的应用价值(英文)

Feasibility of 80 kVp Ultra-low Dose Scan Protocol in Prospective Coronary CT Angiography

目的:探讨在低体重指数患者中使用80 kVp管电压的前瞻性心脏冠脉CTA成像的可行性。方法:对84例临床上怀疑冠心病的患者应用80 kVp管电压的前瞻性心脏冠脉CTA检查。按BMI分为80 kVp(BMI≤22 kg/m^2)和100 kVp(22<BMI≤25)2组。脉冲曝光时间为200 ms(心率≦65次/分)或380 ms(心率>65次/分)。分析直径≥1.5 mm的冠脉节段的图像质量(1~4分),比较各组的图像质量及辐射剂量。结果:两组患者的年龄、身高、心率的一致性较好(P>0.05)。80 k Vp、100 k Vp组的ED分别为(0.56±0.21)mSv、(1.43±0.58)mSv。两组的CT容积剂量指数(CT dose index volume,CTDIvol)、剂量长度乘积(dose length product,DLP)、ED存在显著的统计学差异((P=0.000)。80 kVp、100 kVp组的合格图像分别为92.2%、91.8%。两组的图像质量评分、主动脉SNR及左、右冠主干CNR无统计学差异(P>0.05)。结论:80 kVp的超低剂量前瞻性冠脉CTA可以应用于低体重指数患者,图像质量足以满足诊断需要,辐射剂量显著降低。

Objective： To investigate the feasibility of prospective coronary computed tomography angiography （CTA） using tube voltage of 80 kVp in patients with low body mass index （BMI）. Methods： Eighty-four patients with suspected coronary artery disease （CAD） underwent prospective ECG-gate coronary CTA. The cases were divided into two groups based on BMI： One group （BMI 〈 22 kg/mz） was examined with 80 kVp, and the other group （22 〈 BMI 〈 25） with 100 kVp. If heart rates 〈 65beats/min, pulse exposure time was set at 200 ms, otherwise 380ms. The imaging qualities of coronary artery segments with diameter 〉 1.5 mm were evaluated. Image quality and radiation dose were compared between groups. Results： The age, height, and heart rate were insignificantly different between groups. In the 80 kVp and 100 kV groups, the EDs were 0.56 ±0.21 and （1.43 ± 0.58） mSv, respectively. There were significant differences in CT dose index volume （CTDIvol）, dose length product （DLP） and ED between groups. The image quality rates （score of 3 or 4） were 92.2% and 91.8% in the 80 kVp and 100 kVp groups, respectively. In image quality scores, aortic SNR and coronary trunk CNR had no significant differences between two groups. Conclusion： Prospective coronary CTA using tube voltage of 80 kVp in low-BMI patients can provide adequate coronary diagnostic information; while significantly reduce the radiation dose,