使用VIP-Man模型计算X射线检查的能量传递和有效剂量。

Winslow Mark, Huda Walter, Xu X George, Chao T C, Shi C Y, Ogden Kent M, Scalzetti Ernest M

Nuclear Engineering and Engineering Physics Program, Rensselaer Polytechnic Institute, NES Building, Tibbits Avenue, Troy, NY 12180, USA.

Health Phys. 2004 Feb;86(2):174-82. doi: 10.1097/00004032-200402000-00008.

A male human tomographic model was used to calculate values of energy imparted (epsilon) and effective dose (E) for monoenergetic photons (30-150 keV) in radiographic examinations. Energy deposition in the organs and tissues of the human phantom were obtained using Monte Carlo simulations. Values of E/epsilon were obtained for three common projections [anterior-posterior (AP), posterior-anterior (PA), and lateral (LAT)] of the head, cervical spine, chest, and abdomen, respectively. For head radiographs, all three projections yielded similar E/epsilon values. At 30 keV, the value of E/epsilon was approximately 1.6 mSv J(-1), which is increased to approximately 7 mSv J(-1) for 150 keV photons. The AP cervical spine was the only projection investigated where the value of E/epsilon decreased with increasing photon energy. Above 70 keV, cervical spine E/epsilon values showed little energy dependence and ranged between approximately 8.5 mSv J(-1) for PA projections and approximately 17 mSv J(-1) for AP projections. The values of E/epsilon for AP chest examinations showed very little variation with photon energy, and had values of approximately 23 mSv J(-1). Values of E/epsilon for PA and LAT chest projections were substantially lower than the AP projections and increased with increasing photon energy. For abdominal radiographs, differences between the PA and LAT projections were very small. All abdomen projections showed an increase in the E/epsilon ratio with increasing photon energy, and reached a maximum value of approximately 13.5 mSv J(-1) for AP projections, and approximately 9.5 mSv J(-1) for PA/lateral projections. These monoenergetic E/epsilon values can generate values of E/epsilon for any x-ray spectrum, and can be used to convert values of energy imparted into effective dose for patients undergoing common head and body radiological examinations.

使用男性人体断层模型来计算在X射线检查中，单能光子（30 - 150 keV）的能量传递值（ε）和有效剂量（E）。利用蒙特卡罗模拟获得人体模型中各器官和组织的能量沉积。分别针对头部、颈椎、胸部和腹部的三种常见投照方式[前后位（AP）、后前位（PA）和侧位（LAT）]获得E/ε值。对于头部X线片，所有三种投照方式产生的E/ε值相似。在30 keV时，E/ε值约为1.6 mSv J⁻¹，对于150 keV光子，该值增加到约7 mSv J⁻¹。AP颈椎是唯一研究的投照方式，其E/ε值随光子能量增加而降低。在70 keV以上，颈椎E/ε值几乎没有能量依赖性，PA投照方式的值约为8.5 mSv J⁻¹，AP投照方式的值约为17 mSv J⁻¹。AP胸部检查的E/ε值随光子能量变化很小，约为23 mSv J⁻¹。PA和LAT胸部投照的E/ε值明显低于AP投照，且随光子能量增加而增加。对于腹部X线片，PA和LAT投照之间的差异非常小。所有腹部投照的E/ε比值均随光子能量增加而增加，AP投照的最大值约为13.5 mSv J⁻¹，PA/侧位投照的最大值约为9.5 mSv J⁻¹。这些单能E/ε值可生成任何X射线谱的E/ε值，并可用于将能量传递值转换为接受常见头部和身体放射检查患者的有效剂量。