Pancreatic contrast enhancement with Mn-bis pyridoxal ethylene diamine diacetic acid and the influence of a hormonal stimulation of the pancreas in pigs.

RATIONALE AND OBJECTIVES

Pancreatic and hepatic contrast enhancement after different modes of administration of Mn-bis pyridoxal ethylene diamine diacetic acid (Mn-DPDP) and the influence of the hormones secretin and cholecystokinin on the uptake of this new contrast agent were studied by using magnetic resonance (MR) imaging and atomic absorption spectroscopy (AAS) examinations carried out on 13 young domestic pigs.

METHODS

Mn-DPDP was administered either as bolus injection or 30-min infusion. The course of contrast enhancement was noted. MR imaging was carried out with or without pancreatic stimulation. The Mn content in pancreatic and hepatic tissue was analyzed by using AAS.

RESULTS

Mn-DPDP caused a significant increase (66 +/- 40.1%) in pancreatic signal intensity, an increase in hepatic signal intensity (78 +/- 23.0%), and a significantly higher Mn content on tissue samples of both organs. The results showed a wide individual range. With infusion of Mn-DPDP, pancreatic enhancement was slower, with a peak at 82 +/- 34 min compared with 54 +/- 51 min following bolus injection. The Mn content of both hepatic and pancreatic tissue determined by AAS seemed to be higher after infusion. An incomplete washout of Mn after 24 hr was demonstrated. Hormonal stimulation of the pancreas further increased pancreatic signal intensity but did not influence hepatic contrast enhancement.

CONCLUSION

Infusion is the method of choice for administering Mn-DPDP because it causes an increase in hepatic signal intensity but does not change pancreatic enhancement. Although pancreatic hormonal stimulation intensifies enhancement, the increase is not statistically significant, and this practice will not contribute to day-to-day clinical practice.