Stolzmann Paul, Leschka Sebastian, Betschart Thomas, Desbiolles Lotus, Flohr Thomas G, Marincek Borut, Alkadhi Hatem
University Hospital Zurich, Zurich, Switzerland.
Int J Cardiovasc Imaging. 2009 Apr;25(4):443-51. doi: 10.1007/s10554-008-9397-y. Epub 2008 Dec 12.
The purpose of this study was to assess the radiation dose and associated image noise of previously suggested calcium scoring protocols using dual-source CT.
One hundred consecutive patients underwent coronary calcium scoring using dual-source CT. Patients were randomly assigned to five different protocols: retrospective ECG-gating and tube current reduction to 4% outside the pulsing window at 120 (protocol A) and 100 kV (B), prospective ECG-triggering at 120 (C) and 100 kV (D), and prospective ECG-triggering at 100 kV with attenuation-based tube current modulation (E). Radiation dose parameters and image noise were determined and compared.
Protocol A resulted in an effective dose of 1.3 +/- 0.2 mSv, protocol B in 0.8 +/- 0.2 mSv, protocol C in 1.0 +/- 0.2 mSv, protocol D in 0.6 +/- 0.1 mSv, and protocol E in 0.7 +/- 0.1 mSv. Effective doses were significantly lower (P < 0.001) with 100 kV when compared to 120 kV protocols, and were significantly lower (P < 0.001) for prospective versus retrospective ECG-gating. No significant difference was found between protocol D and E. Significant negative correlations were found between the CTDI(vol) and heart rate for both retrospective ECG-gating protocols (protocol A: r = -0.98, P < 0.001; protocol B: r = -0.83, P < 0.001). The mean image noise was 29.0 +/- 6.7 HU, with no significant differences between the five protocols. The image noise was significantly correlated with the body weight (r = 0.21, P < 0.05) and BMI (r = 0.31, P < 0.01).
Effective dose of calcium scoring using dual-source CT ranges from 0.6 to 1.3 mSv. Prospective triggering and lower tube voltage significantly reduces the radiation but yield similar image noise.
本研究旨在评估使用双源CT的先前建议的钙化积分方案的辐射剂量及相关图像噪声。
连续100例患者接受双源CT冠状动脉钙化积分检查。患者被随机分配到五种不同方案：回顾性心电图门控，在120（方案A）和100 kV（方案B）时将管电流在脉冲窗之外降低至4%；前瞻性心电图触发，在120（方案C）和100 kV（方案D）时；以及在100 kV时采用基于衰减的管电流调制的前瞻性心电图触发（方案E）。确定并比较辐射剂量参数和图像噪声。
方案A的有效剂量为1.3±0.2 mSv，方案B为0.8±0.2 mSv，方案C为1.0±0.2 mSv，方案D为0.6±0.1 mSv，方案E为0.7±0.1 mSv。与120 kV方案相比，100 kV时的有效剂量显著更低（P<0.001），前瞻性心电图门控与回顾性心电图门控相比有效剂量也显著更低（P<0.001）。方案D和E之间未发现显著差异。两种回顾性心电图门控方案（方案A：r = -0.98，P<0.001；方案B：r = -0.83，P<0.001）的容积CT剂量指数（CTDI(vol)）与心率之间均发现显著负相关。平均图像噪声为29.0±6.7 HU，五种方案之间无显著差异。图像噪声与体重（r = 0.21，P<0.05）和体重指数（BMI）（r = 0.31，P<0.01）显著相关。
使用双源CT进行钙化积分的有效剂量范围为0.6至1.3 mSv。前瞻性触发和较低管电压可显著降低辐射，但产生的图像噪声相似。
