Institute for Clinical Radiology; Ludwig-Maximilians-University Hospital Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany.
Eur J Radiol. 2013 Dec;82(12):2217-21. doi: 10.1016/j.ejrad.2013.09.003. Epub 2013 Sep 12.
Coronary CT angiography (CCTA) is usually performed during breath holding to reduce motion artifacts caused by respiration. However, some patients are not able to follow the breathing commands adequately due to deafness, hearing impairment, agitation or pulmonary diseases. The aim of this study was to evaluate the potential of high-pitch CCTA in free breathing patients when compared to breath holding patients.
In this study we evaluated 40 patients (20 free breathing and 20 breath holding patients) with a heart rate of 60 bpm or below referred for CCTA who were examined on a 2nd generation dual-source CT system. Image quality of each coronary artery segment was rated using a 4-point grading scale (1: non diagnostic-4: excellent).
Mean heart rate during image acquisition was 52 ± 5 bpm in both groups. There was no significant difference in mean image quality, slightly favoring image acquisition during breath holding (mean image quality score 3.76 ± 0.32 in breath holding patients vs. 3.61 ± 0.45 in free breathing patients; p = 0.411). Due to a smaller amount of injected contrast medium, there was a trend for signal intensity to be slightly lower in free breathing patients, but this was not statistically significant (435 ± 123 HU vs. 473 ± 117 HU; p=0.648).
In patients with a low heart rate who are not able to hold their breath adequately, CCTA can also be acquired during free breathing without substantial loss of image quality when using a high pitch scan mode in 2nd generation dual-source CT.
冠状动脉 CT 血管造影（CCTA）通常在屏气期间进行，以减少呼吸引起的运动伪影。然而，由于耳聋、听力障碍、躁动或肺部疾病，有些患者无法充分遵循呼吸指令。本研究的目的是评估高心率 CCTA 在自由呼吸患者中的潜在应用价值，并与屏气患者进行比较。
本研究共纳入 40 例心率在 60 次/分或以下的患者，他们因 CCTA 而被转介至我们医院，这些患者在第二代双源 CT 系统上进行了检查。使用 4 分制评分标准（1：无法诊断-4：优秀）对每个冠状动脉节段的图像质量进行评分。
两组患者的图像采集时平均心率分别为 52±5 次/分。两组的平均图像质量无显著差异，屏气组的图像质量略好（屏气组的平均图像质量评分为 3.76±0.32，自由呼吸组为 3.61±0.45；p=0.411）。由于注射的造影剂较少，自由呼吸组的信号强度略低，但无统计学意义（435±123 HU 比 473±117 HU；p=0.648）。
在心率较低且无法充分屏气的患者中，使用第二代双源 CT 的高心率扫描模式，在自由呼吸时也可以获得 CCTA，而不会显著降低图像质量。
