Department of Bioengineering, Rice University, Houston, TX 77005, USA.
Phys Med Biol. 2013 Jul 7;58(13):4455-69. doi: 10.1088/0031-9155/58/13/4455. Epub 2013 Jun 12.
We investigated the possibility of reducing radiation dose to the breast tissue of pediatric females by using multiple tube voltages within a single CT examination. The peak kilovoltage (kVp) was adjusted when the x-ray beam was directly exposing the representative breast tissue of a 5-year-old, 10-year-old, and an adult female anthropomorphic phantom; this strategy was called kVp splitting and was emulated by using a different kVp over the anterior and posterior tube angles. Dose savings from kVp splitting were calculated relative to using a fixed kVp over all tube angles and the results indicated savings in all three phantoms when using 80 kVp over the posterior tube angles regardless of the anterior kVp. Monte Carlo (MC) simulations with and without kVp splitting were performed to estimate absorbed breast dose in voxelized models constructed from the CT images of pediatric female patients; 80 kVp was used over the posterior tube angles. The MC simulations revealed breast dose savings of between 9.8% and 33% from using kVp splitting compared to simulations using a fixed kVp protocol with the anterior technique. Before this strategy could be implemented clinically, the development of suitable image reconstruction algorithms and the image quality of scans with kVp splitting would need further study.
我们研究了在单次 CT 检查中使用多个管电压来降低儿科女性乳房组织辐射剂量的可能性。当 X 射线束直接照射 5 岁、10 岁和成年女性人体模型的代表性乳房组织时，调整峰值千伏值（kVp）；这种策略称为 kVp 分裂，通过在前、后管角度使用不同的 kVp 来模拟。kVp 分裂的剂量节省相对于在所有管角度使用固定 kVp 进行计算，结果表明，在后管角度使用 80 kVp 时，所有三个模型都有节省，而不管前 kVp 如何。使用和不使用 kVp 分裂进行了蒙特卡罗（MC）模拟，以估计从儿科女性患者的 CT 图像构建的体素化模型中的乳房吸收剂量；在后管角度使用 80 kVp。MC 模拟显示，与使用固定 kVp 协议的前技术相比，使用 kVp 分裂可节省 9.8%至 33%的乳房剂量。在该策略可以在临床上实施之前，需要进一步研究合适的图像重建算法和使用 kVp 分裂的扫描图像质量。
