Liu Zi-Yan, Ma Ze-Peng, Gao Kai, Ding Wei, Zhao Yong-Xia
Department of Radiology, The Affiliated Hospital of Hebei University, Baoding City, Hebei Province, People's Republic of China.
J Comput Assist Tomogr. 2025;49(2):265-270. doi: 10.1097/RCT.0000000000001666. Epub 2024 Sep 19.
To compare the image quality and radiation dose in coronary computed tomography angiography (CCTA) based on different acquisition time windows corresponding to the heart rate of breath-holding after free breathing.
Two hundred patients who underwent CCTA with a basal heart rate between 70 and 85 beats/min were divided into groups A and B, with 100 patients in each group. Patients in groups A and B were scanned with the acquisition time window corresponding to the heart rate determined during a breath hold obtained after free breathing and the basal heart rate during free breathing, respectively. Computed tomography (CT) attenuation values of the coronary artery, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. The subjective image scores of the groups were assessed blindly by 2 experienced physicians using a 4-point system, and score consistency was compared using the κ test. The volume CT dose index and dose-length product were recorded for each patient, and the effective dose (ED) was calculated. The Kruskal-Wallis H test was performed to evaluate differences in age, heart rate, and body mass index. A χ2 test was used to evaluate sex differences. An independent-sample t test was employed to compare objective and subjective data such as dose-length product, volume CT dose index, ED, SNR, CNR, and averaged subjective assessment scores. Statistical significance was set at P < 0.05.
No statistically significant differences occurred in sex, age, or body mass index between patients in group A and group B (all P > 0.05). No significant differences occurred in the mean CT values, mean SNR values, mean CNR values, or mean subjective scores of CCTA images between the patients in groups A and B ( P > 0.05). The ED values of the patients in group A were 52.93% lower than those in group B ( P < 0.001).
The radiation dose in CCTA examinations can be significantly reduced while maintaining image quality by narrowing the acquisition time window for breath-holding after free breathing.
比较基于自由呼吸后屏气心率的不同采集时间窗下冠状动脉计算机断层扫描血管造影（CCTA）的图像质量和辐射剂量。
将200例基础心率在70至85次/分钟之间接受CCTA检查的患者分为A组和B组，每组100例。A组和B组患者分别采用与自由呼吸后屏气时测定的心率以及自由呼吸时的基础心率相对应的采集时间窗进行扫描。计算冠状动脉的计算机断层扫描（CT）衰减值、信噪比（SNR）和对比噪声比（CNR）。由2名经验丰富的医师使用4分制对各组的主观图像评分进行盲法评估，并使用κ检验比较评分一致性。记录每位患者的容积CT剂量指数和剂量长度乘积，并计算有效剂量（ED）。采用Kruskal-Wallis H检验评估年龄、心率和体重指数的差异。使用χ2检验评估性别差异。采用独立样本t检验比较剂量长度乘积、容积CT剂量指数、ED、SNR、CNR和平均主观评估得分等客观和主观数据。设定统计学显著性水平为P < 0.05。
A组和B组患者在性别、年龄或体重指数方面均无统计学显著差异（均P > 0.05）。A组和B组患者的CCTA图像平均CT值、平均SNR值、平均CNR值或平均主观评分均无显著差异（P > 0.05）。A组患者的ED值比B组低52.93%（P < 0.001）。
通过缩小自由呼吸后屏气的采集时间窗，在保持图像质量的同时可显著降低CCTA检查中的辐射剂量。
