Conditions: IV Contrast Dosing
Keywords: IV contrast contrast dosing
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 139
Healthy volunteers: no

Brief summary:
There are several different methods that can be used to determine the dose of iodinated contrast material for a CT scan. These include a standard fixed dose, a dose based on total body weight, a dose based on body mass index, a dose based on lean body weight, and a dose based on estimated lean body weight. The fixed dose method uses a predetermined amount of contrast material for all patients having a CT scan of the abdomen regardless of size. This is the standard procedure currently used at Duke. The other methods use the patient's weight, either the total body weight or lean body weight, to determine the amount of contrast necessary for the CT exam. For this study, the investigators will use the fixed dose, total body weight, the lean body weight, and estimated lean body weight methods. The purpose of this study is to evaluate these five methods of determining the IV contrast volume and which may be best for abdominal CT scanning.

Detailed description:

Arms:
arm 1: 50 subjects will receive contrast media based on a fixed dose. Each will receive 125 mL of Isovue 370 (370 mg of iodine/mL) administered at 4 mL/sec (1.48 gmI/sec for 31.25 sec). arm 2: 25 subjects will receive contrast media dose based on the total body weight. Total body weight will be determined. Both men and women will receive contrast media at a dose of 0.7 gmI/kg (1.78 mL of Isovue 370/kg) or 0.30 gmI/lb (0.81 mL of Isovue 370/lb). The injection rate will be 0.058 mL/sec/kg (0.026 mL/sec/lb). arm 3: 25 subjects will receive contrast media dose based on the calculated lean body weight. Total body weight and height will be determined. From this data the lean body weight will be calculated.

Men will receive a dose of 0.86 gmI / kg LBW (2.32 mL of Isovue 370/kg at 0.074 mL/sec/kg) or 0.39 gmI/lb LBW (1.05 mL of Isovue 370/lb at 0.034 mL/sec/lb). Women will receive a dose of 0.92 gmI/kg LBW (2.49 mL of Isovue 370/kg at 0.080 mL/sec/kg) or 0.42 gmI/lb LBW (1.13 mL of Isovue 370/kg at 0.036 mL/sec/kg). arm 4: 50 subjects will receive contrast media dose based on the measured lean body weight. Lean body weight will be determined using the Tanita body composition/analyzer scales. From this data the lean body weight will be calculated.

Men will receive a dose of 0.86 gmI / kg LBW (2.32 mL of Isovue 370/kg at 0.074 mL/sec/kg) or 0.39 gmI/lb LBW (1.05 mL of Isovue 370/lb at 0.034 mL/sec/lb). Women will receive a dose of 0.92 gmI/kg LBW (2.49 mL of Isovue 370/kg at 0.080 mL/sec/kg) or 0.42 gmI/lb LBW (1.13 mL of Isovue 370/kg at 0.036 mL/sec/kg). arm 5: 25 subjects will receive contrast media dose based on the estimated lean body (eLBW) weight. Estimated lean body weight will be determined by using a unique software program which measures the sum of the posterior to anterior attenuation from the digital scout radiograph (abbreviated as sqrt PA) obtained during the standard planning scan of the abdominal/pelvic CT. Men will receive a dose of 0.86 gmI / kg eLBW (2.32 mL of Isovue 370/kg at 0.074 mL/sec/kg) or 0.39 gmI/lb eLBW (1.05 mL of Isovue 370/lb at 0.034 mL/sec/lb). Women will receive a dose of 0.92 gmI/kg eLBW (2.49 mL of Isovue 370/kg at 0.080 mL/sec/kg) or 0.42 gmI/lb eLBW (1.13 mL of Isovue 370/kg at 0.036 mL/sec/kg).

Interventions: intervention 1: Isovue 370 intervention 2: Weight calculation
Intervention descriptions: intervention 1: All contrast media doses administered for this study are within the FDA approved dose range in the package insert. intervention 2: None

Protocol document: