Purpose: To delineate dynamic gadopentetate dimeglumine enhancement profiles within the abdomen as a guide to improve gadolinium-enhanced magnetic resonance (MR) angiography.
Materials and methods: Fifteen patients (eight women, seven men; aged 19-80 years) underwent fast three-dimensional spoiled gradient-recalled-echo imaging with the keyhole technique during the administration of 0.1 mmol/kg gadopentetate dimeglumine by means of bolus (10-second) injection (n = 5), 60 second injection (n = 5), or slow (120-230-second) pump injection (n = 5). Injection was initiated 10 seconds after imaging began. Regions of interest were constructed within the aorta, inferior vena cava, liver, spleen, renal cortex, muscle, and fat. Inclusion of phantoms of gadopentetate dimeglumine in tubes allowed estimation of intravascular gadolinium concentration.
Results: Maximal arterial enhancement occurred with bolus administration; maximal parenchymal organ enhancement, with 60-second injection. Slow pump injection resulted in a longer time to preferential arterial to venous enhancement (120 seconds +/- 14 [+/-standard deviation]) than did bolus (48 seconds +/- 64) or 60-second (88 seconds +/- 39) injections. The peak arterial to venous enhancement ratio was 6.3 +/- 3.3 for the bolus injection, 4.7 +/- 1.6 for the 60-second injection, and 3.3 +/- 1.3 for the slow pump injection.
Conclusion: The dynamics and magnitude of abdominal vascular and soft-tissue enhancement are affected by the rate of gadopentetate dimeglumine administration.