Abdominal multidetector CT in patients with varying body fat percentages: estimation of optimal contrast material dose.

Purpose: To determine if contrast material dose for abdominal multidetector computed tomography (CT), as determined by using body weight (BW), overestimates the amount of contrast material required in heavier patients. Materials and Methods: Institutional review committee approval and patients' written informed consent were obtained. CT images of the abdomen were obtained by using 2 mL per kilogram of BW of intravenous contrast material (300 mg/mL iodine) injected at 4 mL/sec in 161 consecutive patients (age range, 28–90 years; mean age, 63 years; 95 men, 66 women). CT scans were initiated 45 and 150 seconds after aortic enhancement increased by 50 HU. The patients were divided into low (37–54 kg) and high (55–75 kg) BW groups. The ΔHU/I, where ΔHU is change in CT number and I is iodine dose in grams, and adjusted maximum hepatic enhancement (ΔHU/[I/kg]) were assessed for correlation with BW, body mass index (BMI), and body fat percentage (BFP) by using linear regression. Results: ΔHU/I correlated (P < .0...