Optimal timing of abdominal CT in children: relationship to injection rate.

PURPOSE

To study computed tomographic (CT) scanning technique in relationship to rate of injection of contrast material for imaging of the liver and other abdominal organs in pediatric patients.

MATERIALS AND METHODS

The time from start of injection of 2 mL/kg iohexol to peak opacification in the aorta, hepatic vein, liver, and kidney was determined for injection rates of 0-0.99, 1.00-1.99, 2.00-2.99, 3.00-3.99, and 4.00 mL/kg or more per minute in 77 pediatric patients.

RESULTS

Peak liver opacification varied only slightly with different injection rates, but the time from start of injection to peak opacification in the aorta, hepatic vein, liver, and kidney did vary with injection rate.

CONCLUSION

Data provided by this study should allow CT scanning to be timed in relation to injection rate to ensure that maximal organ opacification is achieved as the middle of the organ is being scanned, that adequate hepatic and portal vein opacification is achieved, and that streaking from the renal pelvis is minimized.