Micro-imagerie anatomofonctionelle hépatobiliaire de la souris normale par tomodensitométrie X et scintigraphie planaire sténopée

Objective

Develop the methodology of data acquisition and processing for functional hepatobiliary scintigraphic imaging in normal mice.

Material and methods

The scintigraphic study was done on 11 female adult CD1 mice under gazeous anaesthesia using a small animal dedicated gamma-camera. A dynamic serie of 40 frames with 1 minute per frame was acquired after injection of Tc-99m mebrofenin. Two individuals were used for tomodensitometric morphological acquisitions using an X-ray micro-CT and the injection of a contrast agent and contributed to the choice of the scintigraphic regions of interest. Four analytical models: corrected and deconvolved hepatogram (A), bi-compartmental model (B), fast kinetics compartmental model (C) and factorial analysis (D) were applied to the scintigraphic data starting from areas of interest centered to the cardiac cavities and the liver.

Results

The mebrofenin kinetics is characterized by a time of the maximum t_max ranging between 4.5 and 4.6 min, a time of the center of gravity t_cdg from 6.2 to 7.0 min, a half-life of exponential decay t_1/2decr from 5.4 to 6.8 min, a fraction of hepatic extraction of 100%. Uptake and excretion half-lives are 2.3 and 5.8 min for the bicompratmental model and are 3.2 and 3.3 min for the fast kinetics compartmental model. Comparisons do not find significant differences between the right and left livers nor between models A, B, C and D for uptake time constants nor between models A, B and D for excretion time constants.

Conclusion

Reference values of hepatobiliary function in normal CD1 mice were obtained using different compartmental models.