Department of Medical Imaging, Toronto General Hospital, ON, Canada.
AJR Am J Roentgenol. 2011 Dec;197(6):1328-34. doi: 10.2214/AJR.11.6816.
The purpose of this article is to determine the influence of chest wall composition on image quality in cardiac CT.
A retrospective study of 100 consecutive patients referred for CT coronary artery calcium assessment was performed. Image noise (Hounsfield units) was measured by prescribing a region of interest in the descending thoracic aorta. Image noise was correlated with conventional patient biometric parameters, including body weight, body mass index (BMI), and anteroposterior and lateral thoracic diameters, and with novel patient biometric parameters, including total chest wall soft tissue, chest wall fat, and chest wall muscle and bone. The linear correlation coefficient was used to indicate the strength of the association.
A strong correlation was noted between BMI and image noise in men (r = 0.66), but the strongest relationships were observed in larger women (BMI ≥ 25), who had more chest wall fat than muscle and very strong correlations between image noise, chest wall fat (r = 0.82), and total chest wall soft tissue (r = 0.85).
Chest wall composition has a significant correlation with image noise for cardiac CT. Therefore, strategies that target radiation dose reduction should incorporate adaptation to chest wall composition. These determinations become more significant given the current obesity epidemic.
本文旨在确定胸壁成分对心脏 CT 图像质量的影响。
对 100 例连续因 CT 冠状动脉钙化评估而就诊的患者进行了回顾性研究。通过在降主动脉中规定感兴趣区域来测量图像噪声（亨氏单位）。将图像噪声与常规患者人体测量参数（包括体重、体重指数（BMI）和前后径及横径）以及新型患者人体测量参数（包括胸壁总软组织、胸壁脂肪和胸壁肌肉及骨骼）进行相关性分析。线性相关系数用于表示关联的强度。
在男性中，BMI 与图像噪声之间存在很强的相关性（r = 0.66），但在更大的女性（BMI≥25）中，相关性最强，其胸壁脂肪多于肌肉，图像噪声与胸壁脂肪（r = 0.82）和胸壁总软组织（r = 0.85）之间存在很强的相关性。
胸壁成分与心脏 CT 的图像噪声有显著相关性。因此，针对辐射剂量减少的策略应适应胸壁组成。鉴于当前的肥胖流行，这些测定结果变得更为重要。
