Department of Radiology, University of Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany.
Eur Radiol. 2012 Mar;22(3):569-78. doi: 10.1007/s00330-011-2300-6. Epub 2011 Oct 9.
To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine.
Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation.
Estimates for mean relative ED was 7.1 ± 2.1 mSv/100 mAs for TCM and 12.5 ± 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR (≤60 bpm) was highest (49 ± 5%) compared to intermediate (60-70 bpm, 33 ± 12%) and high HR (>70 bpm, 29 ± 12%). However lowest ED is achieved at high HR (5.2 ± 1.5 mSv/100 mAs), compared with intermediate (6.7 ± 1.6 mSv/100 mAs) and low (8.3 ± 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied.
Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM.
• Monte Carlo simulations allow for individual radiation dose calculations. • ECG-triggered tube current modulation (TCM) can effectively reduce radiation dose. • Slow and regular heart rates allow for highest dose reductions by TCM. • Adaptive pitch accounts for lowest radiation dose at high heart rates. • Women receive higher effective dose than men undergoing spiral coronary CT-angiography.
评估在临床常规中使用双源系统进行心电图触发管电流调制（TCM）和心率（HR）依赖性螺距自适应的螺旋冠状动脉 CT 血管造影（CTA）的患者的辐射剂量水平。
对 56 例患者进行了冠状动脉 CTA 检查，采用了心电图触发管电流调制（TCM）和心率（HR）依赖性螺距自适应。进行了个体蒙特卡罗（MC）模拟以进行剂量评估。采用恒定管电流（CTC）进行回顾性模拟作为参考。对肺组织进行分割，并用于计算器官和有效剂量（ED）。
TCM 的平均相对 ED 估计值为 7.1±2.1 mSv/100 mAs，CTC 为 12.5±5.3 mSv/100 mAs（P<0.001）。与中速（60-70 bpm，33±12%）和高速（>70 bpm，29±12%）相比，低速（≤60 bpm）的相对剂量降低最大（49±5%）。然而，当自动适应螺距时，HR 最高（5.2±1.5 mSv/100 mAs），与中速（6.7±1.6 mSv/100 mAs）和低速（8.3±2.1 mSv/100 mAs）相比，ED 最低。
在低速和常规 HR 下，TCM 可实现高达 52%的辐射剂量节省。但是，通过自适应螺距，尽管 TCM 的辐射剂量降低效果较差，但在 HR 较高时仍可获得最低的 ED。
蒙特卡罗模拟允许进行个体辐射剂量计算。
心电图触发管电流调制（TCM）可有效降低辐射剂量。
缓慢而规则的心率可使 TCM 的剂量降低幅度最大。
自适应螺距可在高心率时达到最低的辐射剂量。
女性在接受螺旋冠状动脉 CT 血管造影时比男性接受更高的有效剂量。
