心电门控320排容积CT在急性胸痛中应用价值的前瞻性研究

目的:探讨前瞻性心电门控320排容积CT对急性胸痛成像的可行性及诊断价值。方法:对连续61例急性胸痛患者不控制心率条件下行前瞻性心电门控wide-volume模式并强制在一个心动周期扫描,曝光时间窗根据心率不同预设在40%~50%R-R间期(心率≥70次/min)或70%~80%R-R间期(心率70次/min)。2个volume涵盖自胸廓入口至心膈面,对比剂采用三相注射法以便同时显示主动脉、冠状动脉、肺动脉三大血管床。评价三大血管床的图像质量及对胸痛病因的诊断能力。记录患者的有效辐射剂量、对比剂用量。结果:61例患者的三大血管床(主动脉、冠状动脉及肺动脉)均得到明显均匀强化。主动脉和肺动脉均获得良好的可诊断图像(可诊断率达100%,61/61)。2例患者因屏气不良冠状动脉图像无法评价,在其余59例患者的625个冠状动脉节段中,图像质量为1级的占94.2%(589/625),2级图像质量占3.2%(20/625),总的可评价率达97.4%。观察者之间总的一致性较好(k=0.83,95%CI:0.60~1.00)。平均有效辐射剂量为(5.44±1.15)mSv,对比剂总量平均为(75.7±4.35)mL。本扫描计划对胸痛病因阳性诊断率为82%(50/61),CTA诊断为阴性的18%(11/61)的患者中随诊一月内无不良并发症出现。结论:320排容积CT的前瞻心电门控wide-volume扫描模式在不控制心率情况下可低辐射剂量及低对比剂用量地对急性胸痛患者进行评价。

Assessment of acute chest pain with prospective ECG-triggered 320-MDCT angiography

Objective：To assess the feasibility of triple rule-out protocol for acute chest pain with 320-MDCT angiography in emergency department. Methods： 61 consecutive patients with acute chest pain underwent triple rule-out CTA using a prospective ECG-gated wide-volume scan protocol without heart rate（ HR）control. The exposure window was set at 40%-50% R-R interval（ HR≥70bpm） or 70%-80% R-R interval（ HR 70bpm） in a single heart beat. The image quality of the pulmonary arteries,the thoracic aorta,and coronary arteries were evaluated for motion artifacts. The mean attenuation was measured in the different level of aorta. The radiation dose and contrast medium volume were recorded. Results： The image quality was acceptable in the aorta（ 100%）,pulmonary arteries（ 100%） and CA（ 97. 4%）. The mean radiation dose was（ 18.42 ±5.02） mSv. The median radiation exposure was（ 5.44 ±1.15） mSv. The mean volume of contrast medium was（ 75. 7 ± 4. 35） mL. The reason of chest pain was diagnosed in 50 /61 patients. There were no adverse outcomes at 30 days in the negative group. Conclusion： For patients with acute chest pain,prospective ECG-gated wide-volume scan in CTA of triple rule-out has the potential to provide diagnostic image of the pulmonary arteries,the thoracic aorta,and coronary arteries with lower radiation exposure.