Hepatic enhancement and metastatic lesion conspicuity on CT scans: influence of intravenous glucagon and oral CT contrast material.

PURPOSE

To determine the effect of glucagon and orally administered contrast material on hepatic enhancement and metastatic lesion conspicuity on computed tomographic (CT) scans.

MATERIALS AND METHODS

Nine patients with a history of hepatic metastasis underwent two CT examinations with intravenously administered contrast material. Each patient was given orally administered CT contrast material for the first examination. No oral contrast material was given in the second examination. Five patients underwent the initial CT with intravenous administration of 1 mg of glucagon; the second examination was performed without glucagon. Four patients were administered glucagon before the second examination, but no glucagon was administered before the first. Attenuation in the liver, portal vein, and aorta was measured by observers blinded to whether the patient had been given glucagon. Lesion conspicuity was rated on a continuous scale.

RESULTS

Greater mean hepatic enhancement was noted on scans of patients in whom oral contrast material was administered (mean, 52 HU) versus those in whom no oral contrast material was administered (mean, 47 HU; P = .019). Glucagon was not associated with greater hepatic enhancement. Neither oral contrast material nor glucagon had a significant effect on lesion conspicuity.

CONCLUSION

Oral CT contrast material is associated with a small increase in hepatic enhancement that does not appear to be clinically important. Glucagon does not appear to affect hepatic enhancement or lesion conspicuity in humans.