Department of Radiology, Ankara Training and Research Hospital, Ankara, Turkey.
Eur Radiol. 2010 Sep;20(9):2100-7. doi: 10.1007/s00330-010-1782-y. Epub 2010 May 1.
To compare the image quality of computed tomography pulmonary angiography (CTPA) obtained with the injection of various low doses of contrast medium (CM) with different injection-related factors.
A total of 90 patients (42 females, 48 males; 54.3 +/- 18.6 years) undergoing CTPA were included. Three CM protocols, each containing 30 patients, were created. Protocols 1, 2 and 3 consisted of a CM of 60 ml, 55 ml and 50 ml, and a bolus trigger level of 120 HU, 90 HU and 75 HU, respectively. Injection was uniphasic for protocols 1 and 2 (flow rate 5 ml/s), and biphasic for protocol 3 (flow rates 5 and 4 ml/s); with saline flushing afterwards. Enhancement was measured in three central and six peripheral pulmonary arteries.
The mean attenuation value for pulmonary arteries was over 250 HU for all protocols. There was no difference between the attenuation levels with the protocols (p > 0.05). The percentage of pulmonary arteries exceeding optimal attenuation (> or =250 HU) showed that protocols 2 and 3 were 90-100% successful (p < 0.05).
The use of proper injection-related factors during CTPA, such as a low trigger level and a high flow rate with saline injection following a decreased CM volume (55 ml or 50 ml), will enable adequate pulmonary artery contrast enhancement.
比较不同注射相关因素下，不同低剂量对比剂（CM）注射的 CT 肺动脉造影（CTPA）的图像质量。
共纳入 90 例患者（42 名女性，48 名男性；54.3±18.6 岁）行 CTPA。制定了 3 种 CM 方案，每个方案包含 30 例患者。方案 1、2 和 3 分别使用 60ml、55ml 和 50ml 的 CM，以及 120HU、90HU 和 75HU 的触发水平。方案 1 和 2 为单相注射（流速 5ml/s），方案 3 为双相注射（流速 5 和 4ml/s），随后使用生理盐水冲洗。在三个中心和六个外周肺动脉中测量增强值。
所有方案中肺动脉的平均衰减值均超过 250HU。方案之间的衰减水平没有差异（p>0.05）。达到最佳衰减（≥250HU）的肺动脉百分比显示方案 2 和 3 的成功率为 90%-100%（p<0.05）。
在 CTPA 期间使用适当的注射相关因素，如低触发水平和高流速，并在减少 CM 体积（55ml 或 50ml）后进行生理盐水注射，可实现足够的肺动脉对比增强。
