Application of free-breathing coronary CT angiography in obese patients
10.3760/cma.j.cn112271-20241124-00454
- VernacularTitle:自由呼吸冠状动脉CT血管造影在肥胖患者的应用研究
- Author:
Yan ZHANG
1
;
Ying WANG
;
Aihui DI
;
Jing LI
;
Ning LANG
;
Huishu YUAN
Author Information
1. 北京大学第三医院放射科，北京 100191
- Publication Type:Journal Article
- Keywords:
Coronary CT angiography (CCTA);
Obesity;
Free breathing;
Breath holding;
Iodinated contrast agent
- From:
Chinese Journal of Radiological Medicine and Protection
2025;45(9):904-910
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the feasibility of the combination of free breathing with the high-threshold, short-delay technique in reducing radiation dose and the volumes of iodinated contrast agent in coronary computed tomography angiography (CCTA) for obese patients.Methods:The data of 73 obese patients with weights > 85 kg and body mass indices (BMIs) > 30 kg/m 2 who received CCTA in the Radiology Department of the Peking University Third Hospital from February 2023 to May 2024 were prospectively collected. These patients were divided into a control group (31 patients) and an experimental group (42 patients). Data were collected from the control group and experimental groups under breath-holding and free-breathing conditions, respectively. The bolus tracking thresholds, delay times, and ICA injection durations were set at 100 HU, 7 s, and 12 s for the control group and at 250 HU, 2 s, and 8 s for the experimental group, respectively. Other scanning and reconstruction parameters of both groups were consistent. The CT values and their standard deviations ( SD) of both groups were assessed and compared, with the CT values involving the lumens of the aorta (AO) root, left anterior descending (LAD), left circumflex artery (LCX), and right coronary artery (RCA). The signal-to-noise ratios (SNR) and contrast-to-noise ratio (CNR) were also calculated. The subjective assessment of image quality was performed for the 18 coronary artery segments using a 4-point scale. The effective radiation doses ( E) and the volumes of iodinated contrast agent of both groups were recorded and compared. The statistical differences in the aforementioned parameters between the groups were tested and analyzed using the analysis of variance (ANOVA), the Mann-Whitney U test, or the χ 2 test. With the results of the ICA as the gold standard, the diagnostic performance of the combination of free-breathing with the high-threshold, short-delay technique in CCTA for obese patients was assessed. Results:There was no statistically significant difference ( P > 0.05) in coronary artery images between both groups, specifically regarding the CT, SNR, and CNR values of the lumens of the AO roots, LAD, LCX, and RCA, as well as the SD values of the AO roots. Both groups received subjective scores of ≥ 3 for coronary artery images, meeting the diagnostic criteria, with no statistically significant differences ( P > 0.05). Compared with the results of the ICA, the analyses of the coronary artery segments of 23 patients from the experimental group, revealed that the accuracy, sensitivity, and specificity of CCTA in the diagnosis of > 50% stenosis were 89%, 86%, and 97%, respectively. Compared to that (45 ml) of the control group, the volume (30 ml) of iodinated contrast agent of the experimental group decreased by 33.3%, with no statistically significant difference in the effective radiation dose ( E) between both groups ( P > 0.05). Conclusions:The combination of free breathing with the high-threshold, short-delay technique can further reduce the volume of the ICA for obese patients while maintaining high CCTA image quality and diagnostic performance.
