Qu Ting-Ting, Li Jian-Ying, Jiao Xi-Jun, Zhang Xiang-Li, Song Zhe-Fan, Guo Yin-Xia, Guo Jian-Xin
1 Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , PR China.
2 CT Research Center, GE Healthcare China , Beijing , China.
Br J Radiol. 2018 Dec;91(1092):20180580. doi: 10.1259/bjr.20180580. Epub 2018 Sep 4.
: To investigate the use of shortened contrast injection with late triggering in coronary CT angiography (CCTA) for decreasing contrast dose and maintaining image quality.
: 106 patients for CCTA on a 16-cm wide-detector CT were prospectively enrolled into groups A (n = 50) and B (n = 56) randomly. Patient weight-dependent contrast medium (Iopamiro, 370 mgI ml) at dose rate of 25 mgI/kg/s was used with 8 s and the standard 10 s injection time in groups A and B, respectively. CT values of the aortic sinus (AS), right coronary artery, left anterior descending and left circumflex at the proximal, middle and distal segments were measured and compared. Subjective image quality was evaluated and analyzed with Fisher exact test. Contrast dose, injection rate and enhancement duration (between the start of enhancement in AS and scan finish) were also compared.
: There was no difference in the injection rate and enhancement duration between the two groups (p > 0.05), while the total contrast dose in group A (36.2 ± 5.7 ml) was significantly lower than in group B (46.4 ± 6.3 ml) (p < 0.001). There was no difference for CT values in all major coronary vessels between the two groups and no difference in subjective image quality scores (all p > 0.05).
: It is feasible to shorten contrast injection to 8 s in CCTA on wide-detector CT systems to significantly reduce contrast dosage, maintain adequate enhancement and reduce contrast-related artifacts.
: (1) Coronary CT angiography (CCTA) scans with shortened contrast medium injection duration and late triggering are feasible with a 16-cm wide-detector CT system (2) Compared with the conventional CCTA with 10 s contrast injection duration, the new contrast injection protocol of using shortened injection duration (to 8 s) and late triggering reduces contrast dose to 36.2 ml, while maintaining adequate enhancement in vessels and reducing contrast-related artifacts.
研究在冠状动脉CT血管造影（CCTA）中使用缩短对比剂注射时间并延迟触发来降低对比剂剂量并维持图像质量。
前瞻性地将106例行16厘米宽探测器CT的CCTA患者随机分为A组（n = 50）和B组（n = 56）。A组和B组分别以25 mgI/kg/s的剂量率使用与患者体重相关的对比剂（碘帕醇，370 mgI/ml），注射时间分别为8秒和标准的10秒。测量并比较主动脉窦（AS）、右冠状动脉、左前降支和左旋支近端、中段和远端的CT值。采用Fisher精确检验对主观图像质量进行评估和分析。还比较了对比剂剂量、注射速率和强化持续时间（AS强化开始至扫描结束之间）。
两组间注射速率和强化持续时间无差异（p > 0.05），而A组的总对比剂剂量（36.2 ± 5.7 ml）显著低于B组（46.4 ± 6.3 ml）（p < 0.001）。两组所有主要冠状动脉血管的CT值无差异，主观图像质量评分也无差异（均p > 0.05）。
在宽探测器CT系统上进行CCTA时，将对比剂注射时间缩短至8秒是可行的，可显著降低对比剂用量，维持足够的强化并减少对比剂相关伪影。
（1）使用16厘米宽探测器CT系统，缩短对比剂注射持续时间并延迟触发进行冠状动脉CT血管造影（CCTA）扫描是可行的。（2）与对比剂注射持续时间为10秒的传统CCTA相比，新的对比剂注射方案采用缩短注射持续时间（至8秒）并延迟触发，可将对比剂剂量降低至36.2 ml，同时维持血管内足够的强化并减少对比剂相关伪影。
