Molecular gastrin receptor localisation in mice using high-resolution SPET-MRI image fusion

摘要

The images demonstrate the biodistribution of ~(99m)Tc-Demogastrin (~(99m)Tc-minigastrin) studied with a high-resolution SPET camera in a mouse bearing an AR4-2J subcutaneous tumour (rat exocrine pancreatic cancer expressing gastrin receptors). SPET sections were matched and fused with high-resolution (300 urn isotropic resolution) MR images of the same animal. Uptake of the ~(99m)Tc-Demogastrin can be seen in the renal cortex (A), the receptor-positive tumour (B), the stomach (organ with the highest physiological receptor expression (C)) and, to a very small extent, in the liver. The uptake in the tumour correlates with the MR signal of the double echo in the steady state (DESS) sequence. Intermediate MR signal areas, indicating vital tumour tissue, show high gastrin uptake. Areas of higher MR signal intensity, indicating oedema and/or necrosis, show lower ~(99m)Tc-Demogastrin uptake.