Optimization of high-concentration (400 mgI/mL) contrast media volume for abdominal computed tomography: a comparison between fixed-dose and total body weight-based protocols

Background: Contrast-enhanced computed tomography (CT) is routinely employed for diagnosing abdominal diseases. Individualized contrast media (CM) dosing protocols are vital for patient safety and image quality. This study aimed to compare the vascular and parenchymal enhancement effects and overall image quality between fixed-dose and total body weight (TBW)-based high-concentration (400 mgI/mL) CM dosing protocols in abdominal multiphasic contrast-enhanced CT. Methods: Patients scheduled for abdominal multiphasic CT were retrospectively enrolled and placed into the TBW-based dosing group or the fixed-dose group (80 mL CM at 120 kVp). The TBW-based dosing group was further divided into five subgroups: 400 mgI/TBW (kg) at 100 kVp, 400 mgI/TBW (kg) at 120 kVp, 450 mgI/TBW (kg) at 100 kVp, 450 mgI/TBW (kg) at 120 kVp, and 500 mgI/TBW (kg) at 120 kVp. The CT attenuation values of blood vessels and organs were measured, and the contrast enhancement index (CEI), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Results: There were no significant differences observed in age, sex, TBW, or body mass index between the fixed-dose group and TBW-based subgroups. The TBW-based dosing groups received a significantly lower volume of CM compared with the fixed-dose group (P