Department of Radiology, George Eliot Hospital NHS Trust, Nuneaton, Warwickshire, UK.
Department of Radiology, George Eliot Hospital NHS Trust, Nuneaton, Warwickshire, UK.
Clin Radiol. 2014 Jan;69(1):36-40. doi: 10.1016/j.crad.2013.07.023. Epub 2013 Sep 23.
To evaluate whether a reduced volume of a higher-concentration iodinated contrast medium delivered with a multiphasic injection could be used in computed tomography pulmonary angiography (CTPA) to achieve a reduction in dose without adversely affecting image quality.
The CTPA images were retrospectively evaluated of 69 patients who received 100 ml of 300 mg iodine/ml ioversol, injected at constant rate of 5 ml/s and 70 patients who received 75 ml of 350 mg iodine/ml ioversol contrast medium delivered using a multiphasic injection protocol (starting at 5 ml/s and reducing exponentially). The degree of opacification in the proximal pulmonary arteries was measured in Hounsfield units.
The groups did not differ in terms of age, sex distribution, or weight. The mean iodine dose was lower in the 75 ml of 350 mg iodine/ml group (26.25 versus 29.5 g, p < 0.0001). Mean opacification did not differ significantly between the 75 ml of 350 mg iodine/ml and 100 ml of 300 mg iodine/ml groups in the main pulmonary artery (365 versus 331, p = 0.055) although it was significantly higher in the 75 ml group in the right (352 versus 315, p = 0.024) and left pulmonary arteries (347 versus 312, p = 0.028). Opacification correlated positively with age and negatively with weight (p < 0.001) and when these effects had been accounted for, the differences in opacification were not statistically significant in the main (p = 0.23), right (p = 0.11), or left pulmonary arteries (p = 0.13). The number of suboptimally opacified studies (opacification of less than 250 HU in main pulmonary artery) did not differ between the groups (12 versus 13, p = 0.83).
A reduction in iodine dose can be achieved without adversely affecting pulmonary arterial enhancement in CTPA by administering a smaller volume of high-concentration contrast medium using a multiphasic injection protocol.
评估在 CT 肺动脉造影（CTPA）中使用多相注射法输送较小体积的高浓度碘造影剂是否可以降低剂量，同时不影响图像质量。
回顾性分析了 69 例接受 100ml 300mg 碘/ml 碘海醇以 5ml/s 恒速注射和 70 例接受 75ml 350mg 碘/ml 碘海醇对比剂的患者的 CTPA 图像，采用多相注射方案（起始速度为 5ml/s，然后呈指数递减）。以亨氏单位测量近端肺动脉的-opacity 程度。
两组在年龄、性别分布或体重方面无差异。75ml 350mg 碘/ml 组的平均碘剂量较低（26.25 与 29.5g，p<0.0001）。在主肺动脉中，75ml 350mg 碘/ml 组与 100ml 300mg 碘/ml 组之间的平均-opacity 无显著差异（365 与 331，p=0.055），但在右（352 与 315，p=0.024）和左肺动脉中 75ml 组的-opacity 显著更高（347 与 312，p=0.028）。-opacity 与年龄呈正相关，与体重呈负相关（p<0.001），当考虑到这些影响时，在主肺动脉（p=0.23）、右肺动脉（p=0.11）或左肺动脉（p=0.13）中，-opacity 的差异无统计学意义。两组中次优-opacity 研究的数量（主肺动脉-opacity 小于 250HU）无差异（12 与 13，p=0.83）。
通过使用多相注射方案输送较小体积的高浓度造影剂，可以在不影响 CTPA 肺动脉增强的情况下降低碘剂量。
