Effect of patient weight and scanning duration on contrast enhancement during pulmonary multidetector CT angiography.

Purpose: To retrospectively evaluate the amount of contrast medium required with 16- and 64-section computed tomography (CT) for a given patient weight to achieve desirable contrast enhancement during pulmonary CT angiography. Materials and Methods: Institutional review board approval was obtained, and informed consent was not required for this HIPAA-compliant study. Eighty-five patients (35 men, 50 women; range, 22–87 years) who had undergone 16-section (n = 48) or 64-section (n = 37) CT for the detection of pulmonary embolism were retrospectively evaluated. Contrast medium containing 350 mg of iodine per milliliter was injected at a rate of 4 mL/sec. The injected volume corresponded to the injection rate multiplied by the sum of the scanning delay plus the scanning duration, up to 125 mL. The scanning delay was determined with bolus tracking. Contrast enhancement was measured in the main pulmonary artery and the aorta. For each patient, the injected contrast medium volume per body weight index was calcu...