The dosage of contrast agents for computed tomography contrast studies is calculated based on the parameter of actual body weight (ABW) to ensure reproducibility. The use of lean body weight (LBW) and adjustment for physique (lean or obese) improves accuracy. However, this method is complex, because LBW is not a general body parameter and requires a special device to measure. To solve this problem, contrast body weight (CBW), has been proposed as a new and simple parameter that considers physique. CBW is calculated by determining the blood volume ratio based on body height, ABW, and sex and can potentially correct for body size. It can be calculated by entering a formula in a Microsoft Excel sheet. Since CBW can be easily obtained using this general tool, we decided to compare the two body parameters of ABW and CBW. We compared ABW and CBW and demonstrated a higher correlation between CBW-based dosing and the amount of iodine used per body weight than with ABW-based dosing. CBW-based dosing allows correction for body size. This indicates that contrast enhancement over a spectrum of lean or obese examinees can be linearly evaluated. To date, this method has shown good results.
Keywords: Blood volume; Body mass index; Body weight; Contrast enhancement; Height; sex.