Shehu M S, Garba N N, Nasiru R, Abdullahi M, Muhammad A
Department of Physics, Baze University, Abuja, Federal Capital Territory, Nigeria.
Department of Physics, Ahmadu Bello University, Zaria, Kaduna State, Nigeria.
Radiol Phys Technol. 2025 Sep 17. doi: 10.1007/s12194-025-00962-7.
This study used AAPM Report 293 to estimate absorbed doses (EADs) from head and neck CT examinations in 100 patients (ages 18-90), leveraging its superior accuracy over Report 220. The study used data from a diagnostic CT scanner of model Canon Aquilion Lightning 16-row 32-slice, between years 2022 to 2024, with IndoseCT version 20b software to extract parameters, such as volumetric CT dose index (CTDI), dose length product (DLP), X-ray tube current (mAs), X-ray tube voltage (kVp) and Size Specific Dose Estimation (SSDE) based on water equivalent diameter (D). Two IndoseCT methods were employed: Z-axis Slice Number technique for D and Z-axis Slice range technique for EAD. A correlation analysis using Pearson Correlation Coefficient (PCC) and Principal Component Analysis (PCA) investigated relationships between CT dose and patient size parameters. The analysis was conducted using Microsoft Excel software embedded with XLSTAT 2024 version. Results showed CTDIvol values were higher than SSDE in most age groups, except 40-59 and 70-79 years. EADs ranged from 29.21 ± 8.12 mGy for (18-30) to 33.07 ± 5.81 mGy for (≥ 30) age groups. Conversion factors (CF) were varied, with notable impact from the 70-79 age group. this study found similar trends in CTDIvol to SSDE conversion factors (CF) as past work, with a mean CF < 1 indicating slight underestimation of radiation dose (SSDE). Notably, by including the 70-79 age group, CF can be shifted from < 1 to > 1; this suggests that patient size in the 70-79 age group may require protocol optimization.
本研究利用美国医学物理师协会（AAPM）第293号报告，对100名年龄在18至90岁之间的患者进行头颈部CT检查的吸收剂量（EADs）进行估算，该报告的准确性优于第220号报告。该研究使用了2022年至2024年间佳能Aquilion Lightning 16排32层诊断CT扫描仪的数据，采用IndoseCT 20b版软件提取诸如容积CT剂量指数（CTDI）、剂量长度乘积（DLP）、X射线管电流（mAs）、X射线管电压（kVp）以及基于水等效直径（D）的尺寸特定剂量估算（SSDE）等参数。采用了两种IndoseCT方法：用于D的Z轴切片数技术和用于EAD的Z轴切片范围技术。使用Pearson相关系数（PCC）和主成分分析（PCA）进行相关性分析，以研究CT剂量与患者尺寸参数之间的关系。分析使用嵌入了XLSTAT 2024版的Microsoft Excel软件进行。结果显示，除了40至59岁和70至79岁年龄组外，大多数年龄组的CTDIvol值高于SSDE。EADs范围从（18至30岁）组的29.21±8.12 mGy到（≥30岁）组的33.07±5.81 mGy。转换因子（CF）各不相同，70至79岁年龄组有显著影响。本研究发现CTDIvol与SSDE转换因子（CF）的趋势与以往研究相似，平均CF<1表明辐射剂量（SSDE）略有低估。值得注意的是，纳入70至79岁年龄组后，CF可从<1变为>1；这表明70至79岁年龄组的患者尺寸可能需要优化扫描方案。
