Dougeni E, Chapple C L, Willis J, Panayiotakis G
Regional Medical Physics Department, Freeman Hospital, Freeman Road, Newcastle upon Tyne NE7 7DN, UK.
Radiat Prot Dosimetry. 2011 Sep;147(1-2):147-50. doi: 10.1093/rpd/ncr288. Epub 2011 Jul 9.
Current concerns focus on the high doses encountered in computed tomography (CT) examinations as they are extending towards younger and more radiosensitive patients. Previous work produced conversion coefficients for effective dose (E) from dose-length product (DLP) for four anatomical body regions applicable to any patient size. This work aims to update the earlier work, incorporating the new ICRP 2007 tissue-weighting factors and testing the methodology on modern scanners. For each age and body region, E was determined relative to DLP. Measurements were carried out on a 64-slice scanner to test this methodology. The conversion coefficients show exponential decrease with patient size. Conversion factors for the pelvis region are lower than before (30-40 %), those for the chest increased (by up to 25 %) whereas those for the head and abdomen remained fairly similar. Application of the coefficients to modern scanners verified the results, so that this methodology can be applied for a wide range of paediatric CT examinations.
当前的关注点集中在计算机断层扫描（CT）检查中所遇到的高剂量问题，因为这类检查正逐渐应用于更年轻且对辐射更敏感的患者。先前的研究得出了适用于任何患者体型的四个身体解剖区域从剂量长度乘积（DLP）到有效剂量（E）的转换系数。这项工作旨在更新早期研究，纳入国际辐射防护委员会（ICRP）2007年的新组织权重因子，并在现代扫描仪上测试该方法。对于每个年龄和身体区域，有效剂量（E）是相对于剂量长度乘积（DLP）确定的。在一台64层扫描仪上进行了测量以测试该方法。转换系数显示随着患者体型增大呈指数下降。骨盆区域的转换因子比以前更低（低30 - 40%），胸部的转换因子有所增加（高达25%），而头部和腹部的转换因子保持相当相似。将这些系数应用于现代扫描仪验证了结果，因此该方法可应用于广泛的儿科CT检查。
