改良单次短时屏气法用于血管减影冠状动脉CT成像

目的 观察改良单次短时屏气法用于血管减影冠状动脉CT成像（S-CCTA）的价值。方法 收集21例冠状动脉钙化复查（n=18）或冠状动脉支架植入术后（n=3）患者，采用改良单次短时屏气法行S-CCTA扫描，获得两次扫描图像和减影后图像后进行处理，采用4分制评价冠状动脉CT血管成像（CCTA）及S-CCTA图像质量，观察以严重钙化节段评估管腔狭窄程度的能力，并计算有效辐射剂量（ED）。结果 21例患者屏气时间为（10.34±1.07）s，辐射ED为（3.43±1.04）mSv。18例冠状动脉钙化复查患者共90个钙化斑块，S-CCTA图像质量（3.47±0.69）分]明显高于CCTA（2.48±0.70）分，P<0.001），且S-CCTA图像所示可用于评估管腔狭窄程度的严重钙化冠状动脉节段（88.89%）明显多于CCTA图像（66.67%，P<0.001）；3例冠状动脉支架植入术后患者共植入5枚支架，其S-CCTA图像质量（2.75±0.29）分]明显高于CCTA（1.84±0.23）分，P<0.05]。结论 改良单次短时屏气S-CCTA可有效缩短屏气时间、减少辐射剂量并提高冠状动脉图像质量。

Modified single short-time breath-holding method applicated in subtraction coronary CT angiography

Objective To observe the application value of modified single short-time breath-holding method in subtraction coronary CT angiography (S-CCTA). Methods Twenty-one patients who received re-examination of coronary calcifications (n=18) or after coronary stent implantation (n=3) were collected and underwent modified single short-time breath-holding S-CCTA. The images obtained from 2 times of scanning and subtraction were processed. The image qualities of coronary CT angiography (CCTA) and S-CCTA were evaluated using a 4-point scale, and the effective dose (ED) was calculated. Results The breath-holding time was (10.34±1.07)s, and the radiation ED was (3.43±1.04)mSv. The image qualities of S-CCTA of 90 calcified plaques in 18 patients with coronary calcifications (3.47±0.69] points) were significantly higher than those of CCTA (2.48±0.70] points, P<0.001), and S-CCTA images showed that the severe calcified coronary segments (88.89%) which could be used to evaluate the degree of lumen stenosis were significantly more than those of CCTA (66.67%, P<0.001), while the image qualities of S-CCTA (2.75±0.29] points) of 5 stents in 3 patients were significantly higher than those of CCTA (1.84±0.23] points, P<0.05). Conclusion The modified single short-time breath-holding S-CCTA could effectively shorten the breath-holding time, reduce radiation ED and improve image quality of CCTA.