Lin Chengxiang, Shen Xigang, Gu Yajia, Qiao Zhongwei, Peng Weijun
Department of Radiology, Children's Hospital of Fudan University, National Children's Medical Center, Fudan University, Shanghai, China.
Department of Radiology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
Quant Imaging Med Surg. 2024 Jun 1;14(6):4031-4040. doi: 10.21037/qims-23-1731. Epub 2024 May 20.
The rapid increase in the use of radiodiagnostic examinations in China, especially computed tomography (CT) scans, has led to these examinations being the largest artificial source of per capita effective dose (ED). This study conducted a retrospective analysis of the correlation between image quality, ED, and body composition in 540 cases that underwent thyroid, chest, or abdominal CT scans. The aim of this analysis was to evaluate the correlation between the parameters of CT scans and body composition in common positions of CT examination (thyroid, chest, and abdomen) and ultimately inform potential measures for reducing radiation exposure.
This study included 540 patients admitted to Fudan University Shanghai Cancer Center from January 2015 to December 2019 who underwent both thyroid or chest or abdominal CT scan and body composition examination. Average CT values and standard deviation (SD) values were collected for the homogeneous areas of the thyroid, chest, or abdomen, and the average CT values and SD values of adjacent subcutaneous fat tissue were measured in the same region of interest (ROI). All data were measured three times, and the average was taken to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for each area. The dose-length product (DLP) was recorded, and the ED was calculated with the following: formula ED = k × DLP. Dual-energy X-ray was used to determine body composition and obtain indicators such as percentage of spinal and thigh muscle. Pearson correlation coefficient was used to analyze the correlations between body composition indicators, height, weight, body mass index (BMI), and ED.
The correlation coefficients between the SNR of abdominal CT scan and weight, BMI, and body surface area (BSA) were -0.470 (P=0.001), -0.485 (P=0.001), and -0.437 (P=0.002), representing a moderate correlation strength with statistically significant differences. The correlation coefficients between the ED of chest CT scans and weight, BMI, spinal fat percentage, and BSA were 0.488 (P=0.001), 0.473 (P=0.002), 0.422 (P=0.001), and 0.461 (P=0.003), respectively, indicating a moderate correlation strength with statistical differences. There was a weak statistically significant correlation between the SNR, CNR, and ED of the other scans with each physical and body composition index (P=0.023).
There were varying degrees of correlation between CT image quality and ED and physical and body composition indices, which may inform novel solutions for reducing radiation exposure.
中国放射诊断检查的使用迅速增加，尤其是计算机断层扫描（CT），这使得这些检查成为人均有效剂量（ED）的最大人工来源。本研究对540例接受甲状腺、胸部或腹部CT扫描的病例的图像质量、有效剂量和身体成分之间的相关性进行了回顾性分析。该分析的目的是评估CT扫描参数与CT检查常见部位（甲状腺、胸部和腹部）的身体成分之间的相关性，并最终为减少辐射暴露的潜在措施提供依据。
本研究纳入了2015年1月至2019年12月在复旦大学附属上海肿瘤医院住院的540例患者，这些患者同时接受了甲状腺或胸部或腹部CT扫描以及身体成分检查。收集甲状腺、胸部或腹部均匀区域的平均CT值和标准差（SD）值，并在同一感兴趣区域（ROI）测量相邻皮下脂肪组织的平均CT值和SD值。所有数据均测量三次，取平均值计算每个区域的信噪比（SNR）和对比噪声比（CNR）。记录剂量长度乘积（DLP），并使用以下公式计算有效剂量：有效剂量=k×DLP。采用双能X射线测定身体成分，并获得脊柱和大腿肌肉百分比等指标。使用Pearson相关系数分析身体成分指标、身高、体重、体重指数（BMI）和有效剂量之间的相关性。
腹部CT扫描的SNR与体重、BMI和体表面积（BSA）之间的相关系数分别为-0.470（P=0.001）、-0.485（P=0.001）和-0.437（P=0.002），表明具有中等相关强度且差异有统计学意义。胸部CT扫描的有效剂量与体重、BMI、脊柱脂肪百分比和BSA之间的相关系数分别为0.488（P=0.001）、0.473（P=0.002）、0.422（P=0.001）和0.461（P=0.003），表明具有中等相关强度且有统计学差异。其他扫描的SNR、CNR和有效剂量与各身体和身体成分指标之间存在微弱的统计学显著相关性（P=0.023）。
CT图像质量与有效剂量以及身体和身体成分指标之间存在不同程度的相关性，这可能为减少辐射暴露提供新的解决方案。
