EFFECT OF RATE OF CONTRAST-MEDIUM INJECTION ON HEPATIC ENHANCEMENT ATCT

PURPOSE: To determine the effect of the rate of contrast medium inject ion on liver enhancement at computed tomography (CT). MATERIALS AND ME THODS: Forty-five patients who underwent a follow-up CT examination of the liver were included in five different groups according to the com pared rates of contrast material delivery: group A, 2 versus 3 mL/sec; group B, 2 versus 4.5 mL/sec; group C, 3 versus 4.5 mL/sec; group D, 3 versus 6 mL/sec; and group E, 4.5 versus 6 mL/sec. RESULTS: Time to peak enhancement was shorter for the faster rates of injection. In eac h group, maximum enhancement was nearly identical for the paired exami nations (group A, 57 vs 58 HU; group B, 48 vs 47 HU; group C, 55 vs 58 HU; group D, 55 vs 54 HU; group E, 62 vs 61 HU, respectively). Mean e nhancement in each group was similar when calculated at 3-second inter vals. CONCLUSION: Higher rates of injection shorten the time to peak l iver enhancement hut have no effect on maximum liver enhancement.