320排CT冠状动脉成像:100 kV对不同体质量者图像质量、噪声及剂量的影响  

Impact of 100 kV on Image Quality,Noise and Radiation Dose of Coronary Angiography with 320-Row CT in Patients with Different Body Mass Index

作　　者：刘红艳[1] 曾庆千 杨栋梁[1] 黄俊毅[1] 卢俊英[1] 黄奕妆 

机构地区：[1]广东省清远市人民医院影像中心,511518

出　　处：《临床放射学杂志》2013年第8期1189-1192,共4页Journal of Clinical Radiology

摘　　要：目的探讨100 kV对不同体质量者320排CT冠状动脉成像(CTCA)图像质量、噪声及剂量的影响。方法连续搜集采用100 kV进行320排CT冠状动脉成像检查者472例,男254例,女218例,平均年龄(60.5±12.2)岁。其中15例心律不齐,4例频发早搏。心率<65次/min者,曝光70%～80%R-R时间窗;心率>65次/min者,曝光30%～80%R-R时间窗。按体重指数(BMI)<20 kg/m2、20 kg/m2≤BMI≤25 kg/m2、25 kg/m2<BMI≤30 kg/m2分为3组。图像质量采用双盲5分评分法(1分为不能诊断,5分为图像质量优),并计算有效辐射剂量(ED)。以感兴趣区(ROI)大小为2 cm×2 cm进行升主动脉根部层面噪声标准差(SD)的测量。评价每组间图像质量、SD及ED的差异。结果图像质量评分4分以上占90.25%(426/472)。3组图像质量评分、SD及ED分别为(4.71±0.65)分、(4.60±0.78)分、(4.62±0.80)分;(26.13±6.59)HU、(30.25±7.15)HU、(33.94±7.44)HU;(4.80±2.67)mSv、(4.70±3.04)mSv、(4.20±2.81)mSv。3组间比较SD差异有统计学意义(P=0.000),图像质量评分及ED差异无统计学意义(P>0.05)。结论 320排CT在25 kg/m2<BMI≤30 kg/m2时采用100 kV行CTCA,图像质量能够满足临床诊断需求。使用70%～80%R-R时间窗曝光,可进一步有效减少ED。Objective To explore the impact of lOOkV on image quality, noise and radiation dose with 320-row CT coronary angiography（CTCA） for patients with different body mass index. Methods 472 consecutive patients （M/F 254/ 218, mean age 60.5 ：i： 12.2 years） who underwent prospective ECG gated CTCA with 100kV, adaptive mA modulation were enrolled ,including 15 patients with arrhythmia and 4 patients with premature pulsing. All scans were performed using 70 -80% R-R interval when the heart rate lower than 65 bpm, and 30 -80% R-R interval in patients with heart rate faster than 65 bpm. The patients were divided into three groups according to the body mass index（BMI） including 〈 20 kg/m2 （n = 68 ） , 20 - 25 kg/m2 （ n = 281 ） , 25 - 30 kg/m2 （ n = 123 ）. Image quality for coronary arteries was assessed using a 5- point scale （1-non-diagnostic; 5-excellent）by two readers blinded to patient information and scan parameters. The effective dose （ED） was calculated. The image noise presented as standard deviation（SD） was measured for each patient on ascend- ing aorta with region of interest （ROI） 2 cm x 2 cm. Image quality, noise, and ED between the groups were compared. Results The image quality score above 4 was 90.25% （426/472）. The mean image quality score, SD and ED of three groups were 4.71± 0.65 vs 4.60 ±0.78 vs 4.62 ± 0.80 seore, （26.13 ±6.59 ） HU vs （ 30.25 ± 7.15 ） HU vs （ 33.94 ± 7.44） HU, and （4.80± 2.67 ） rosy vs （ 4.70± 3.04 ） mSv vs （ 4.20± 2.81 ） mSv respectively. There was significant difference in SD among the three BMI groups （ F = 27. 023, P = 0. 000）. However, there was no significant difference in the image quality score and ED among them（P 〉 0.05）. Conclusion The lOOkV setting is feasible for patients with 25 〈 BMI〈30 kg/m2 when combined with adaptive mA modulation on 320-row CTCA, which can maintain diagnostic imagequality. It can be effective to reduce ED on using 70 - 80% R-R interval scanning.

关 键 词：冠状动脉 图像质量噪声辐射剂量体层摄影术 x线计算机 

分 类 号：R816.2[医药卫生—放射医学]