Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
AJR Am J Roentgenol. 2010 Mar;194(3):W272-7. doi: 10.2214/AJR.09.2970.
The objective of our study was to prospectively investigate the effect of adjusting the scan length of CT coronary angiography using the calcium scoring images instead of the scout view with regard to radiation dose.
One hundred twenty-five consecutive patients (mean age +/- SD, 62 +/- 10 years) undergoing both calcium scoring and CT coronary angiography were included in our study. The scan length of calcium scoring was planned on the scout view; the scan length of CT coronary angiography was planned on the axial images of the calcium scoring by identifying the origin of the left main artery and cardiac apex and adding 1 cm cranially and caudally. Effective radiation doses were calculated for CT coronary angiography using both scout view-derived and calcium scoring-derived scan lengths.
The scout view-derived scan length (mean +/- SD, 139 +/- 13 mm) was significantly greater than the calcium scoring-derived scan length (117 +/- 9 mm; p < 0.01). The average radiation dose was 0.8 +/- 0.3 mSv (range, 0.6-1.5 mSv) for calcium scoring and 9.0 +/- 0.6 mSv (range, 6.5-10.2 mSv) for CT coronary angiography. Using the scout view-derived scan length would have been associated with an effective radiation dose of 10.7 +/- 1.2 mSv (mean +/- SD) for CT coronary angiography, which is significantly higher than that using the calcium scoring-derived scan length (p < 0.05). The average difference between CT coronary angiography using a calcium scoring-derived scan length and that using a scout view-derived scan length was 1.7 +/- 0.9 mSv, corresponding to a radiation dose reduction of 16%. The average dose reduction when using a calcium scoring-derived instead of a scout view-derived scan length for CT coronary angiography-including the radiation dose of the calcium scoring scan-was 1.2 +/- 0.8 mSv (range, 0.1-2.7 mSv) (p < 0.05).
Adjustment of the scan length of CT coronary angiography using the images from calcium scoring instead of the scout view is feasible and is associated with a 16% reduction in radiation dose of dual-source CT coronary angiography.
本研究旨在前瞻性地研究使用钙评分图像而不是扫描视图来调整 CT 冠状动脉成像的扫描长度对辐射剂量的影响。
本研究纳入了 125 例连续进行钙评分和 CT 冠状动脉成像的患者（平均年龄 +/- 标准差，62 +/- 10 岁）。钙评分的扫描长度是在扫描视图上计划的；CT 冠状动脉成像的扫描长度是在钙评分的轴位图像上计划的，通过识别左主干和心尖的起源，并在头侧和尾侧增加 1cm。使用扫描视图和钙评分衍生的扫描长度分别计算 CT 冠状动脉成像的有效辐射剂量。
扫描视图衍生的扫描长度（平均值 +/- 标准差，139 +/- 13mm）明显大于钙评分衍生的扫描长度（117 +/- 9mm；p < 0.01）。平均辐射剂量为钙评分 0.8 +/- 0.3 mSv（范围，0.6-1.5 mSv），CT 冠状动脉成像 9.0 +/- 0.6 mSv（范围，6.5-10.2 mSv）。使用扫描视图衍生的扫描长度会导致 CT 冠状动脉成像的有效辐射剂量为 10.7 +/- 1.2 mSv（平均值 +/- 标准差），明显高于使用钙评分衍生的扫描长度（p < 0.05）。使用钙评分衍生的扫描长度与使用扫描视图衍生的扫描长度进行 CT 冠状动脉成像之间的平均差异为 1.7 +/- 0.9 mSv，相当于辐射剂量减少 16%。当使用钙评分衍生的扫描长度而不是扫描视图衍生的扫描长度进行 CT 冠状动脉成像时，包括钙评分扫描的辐射剂量在内，平均剂量减少 1.2 +/- 0.8 mSv（范围，0.1-2.7 mSv）（p < 0.05）。
使用钙评分图像而不是扫描视图来调整 CT 冠状动脉成像的扫描长度是可行的，与双源 CT 冠状动脉成像的辐射剂量减少 16%相关。
