基于双源CT大螺距动脉晚期扫描进行左心耳影像学评估的临床应用

Evaluation for left atrial appendage imaging based on high-pitch late arterial phase scanning by dual-source CT

目的 探讨利用双源CT大螺距动脉晚期扫描进行左心耳(LAA)充盈程度评估及形态学测量的临床应用价值。方法 选取2022年6月至10月空军军医大学第二附属医院因心房颤动(AF)需要行LAA CT血管造影的患者80例,收集患者临床资料并行第二代双源CT大螺距Flash扫描模式,随机分为A组40例(动脉期扫描)和B组40例(动脉晚期扫描),所有患者均行双期扫描,间隔时间均为30 s。根据第1期LAA是否完全充盈分为LAA充盈组59例和未充盈组21例。记录患者接受的辐射剂量;测量LAA、同层面升主动脉(AA)、最大层面左心房(LA)共3个部位的CT值,同时测量LAA开口短径、长径、面积及LAA深度。结果 80例患者第1期辐射剂量为2.2(2.0,3.9)mSv、第1期+延迟期辐射剂量为2.7(2.4,4.8)mSv,第1期与第1期+延迟期扫描辐射剂量比较,差异有统计学意义(P<0.01);B组LAAHU/AAHU、LAAHU/LAHU、第1期LAA充盈比例高于A组,差异有统计学意义(P<0.05,P<0.01);LAA充盈组LAA开口长径、LAA开口短径、LAA开口面积、LAA深度低于LAA未充盈组,差异有统计学意义[(26.6±3.1)mm vs(30.1±2.8)mm,P<0.01;(20.8±2.9)mm vs(22.8±2.1)mm,P<0.01;(454.6±92.1)mm2vs(561.9±85.9)mm2,P<0.01;(35.8±4.8)mm vs(40.7±5.4)mm,P<0.01]。结论 采用双源CT大螺距Flash动脉晚期扫描,LAA完全充盈率大幅提高,缩短检查时间的同时降低了患者的辐射剂量,值得临床应用推广。

Objective To explore the application of high-pitch late artery scanning by dual-source CT in evaluating the filling defect and morphological measurement of left atrial appendage(LAA).Methods A total of 80patients requiring LAA CT angiography(CTA)scanning due to atrial fibrillation(AF)admitted in our hospital from July to October 2022were enrolled,and their clinical data were collected.The second-generation dual-source CT high-pitch FLASH scanning was adopted to all the patients who were randomly divided into group A(arterial phase scanning,40cases)and group(late arterial phase scanning B,40cases).All patients underwent dual-phase scanning and the time interval was 30s.According to the filling defects of LAA in the first phase,the patients were divided into LAA filling group(n=59)and non-filling group(n=21).The radiation dose the patients received was recorded.The CT values of LAA,ascending aorta(AA)at the same slice and left atrium(LA)at its largest slice were calculated,and the short diameter,long diameter,area of LAA opening and depth of LAA were also measured.Results The radiation dose received in patients in phase 1was 2.2(2.0,3.9)mSv,and that in phase 1+delayed was 2.7(2.4,4.8)mSv,with significant difference between the first and the first+delayed scanning period(P<0.01).The ratios of CT values(LAAHU/AAHUand LAAHU/LAHU)and of LAA filling defect in the first phase were significantly higher in the group B than the group A(P<0.05,P<0.01).The long diameter,short diameter,area of LAA opening and depth of LAA were obviously lower in the LAA filling group than the non-filling group(26.6±3.1mmvs 30.1±2.8mm,P<0.01;20.8±2.9mmvs 22.8±2.1mm,P<0.01;454.6±92.1mm2 vs 561.9±85.9mm2,P<0.01;35.8±4.8mmvs 40.7±5.4mm,P<0.01).Conclusion High-pitch Flash late arterial phase scanning by dual source CT can significantly elevate the LAA filling defects,shorten the examination time and reduce the radiation dose in patients.It is worthy of clinical application and promotion.