Department of Radiology, University Hospitals Bristol and Weston NHS Foundation Trust, Upper Maudlin Street, Bristol BS2 8HW, UK.
University of Bristol, Faculty of Health Sciences, Queens Road, Bristol BS8 1QU, UK.
Clin Radiol. 2023 Mar;78(3):e237-e242. doi: 10.1016/j.crad.2022.11.007. Epub 2022 Dec 30.
To compare the thoracic vascular opacification achieved using the standard bolus-tracking protocol (BTP) with a fixed-timing protocol (FTP) with a modified breathing instruction during computed tomography pulmonary angiography (CTPA) examinations.
A single-centre review of CTPA examinations performed between July 2018 and January 2019 using the BTP or FTP and weight-based contrast dosing of 20 mg iodine/kg body weight/s for 20 seconds at 100 kV tube potential. Radiodensity (in Hounsfield units) was analysed in the right ventricle, main pulmonary artery (MPA), left atrium, left ventricle, and ascending and descending thoracic aorta (DTA). A p-value of <0.05 was considered significant.
Of 782 examinations, 88 BTP and 90 FTP examinations were included. Mean attenuation of the MPA was similar in the FTP (396 ± 106 HU) and BTP (362 ± 119 HU; p=0.06); however, good-quality (≥250 HU) MPA opacification was achieved in more FTP examinations (87/90, 96.7%) compared to the BTP (73/88, 82.9%; p=0.002). Mean attenuation of the DTA was better in the FTP (325 ± 72 HU) than the BTP (228 ± 75 HU; p <0.0001), with good-quality opacification (≥250 HU) in 76/90 (84.4%) FTP examinations compared with 36/88 (40.9%) BTP examinations (p <0.001).
The FTP achieves better opacification of the MPA and DTA compared to the BTP.
比较在计算机断层肺动脉造影（CTPA）检查中使用标准团注追踪（BTP）和固定定时（FTP）方案，并结合改良呼吸指令时所获得的胸部血管显影效果。
回顾性分析 2018 年 7 月至 2019 年 1 月间在 100kV 管电压下，使用 20mg 碘/kg 体重/s 进行 20 秒的体重剂量对比剂注射，行 BTP 或 FTP 方案的 CTPA 检查。分析右心室、主肺动脉（MPA）、左心房、左心室以及升主动脉和降主动脉（DTA）的放射密度（以亨氏单位表示）。p 值＜0.05 认为有统计学意义。
782 例检查中，有 88 例 BTP 检查和 90 例 FTP 检查被纳入分析。FTP（396±106HU）和 BTP（362±119HU）方案中 MPA 的平均衰减相似（p=0.06）；然而，FTP 方案（87/90，96.7%）获得高质量（≥250HU）MPA 显影的比例高于 BTP 方案（73/88，82.9%）（p=0.002）。FTP 方案（325±72HU）的 DTA 平均衰减优于 BTP 方案（228±75HU；p＜0.0001），76/90（84.4%）FTP 检查中获得高质量（≥250HU）显影，而 36/88（40.9%）BTP 检查中获得高质量显影（p＜0.001）。
与 BTP 相比，FTP 方案能更好地显影 MPA 和 DTA。
