Magnetic resonance imaging of plugged homograft fat after transsphenoidal surgery

The auther studied the changes of magnetic resonance (MR) images of the epidual transplanted honograft fats in dogs and the intrasellar plugged homograft fats after the transsphenoidal pituitary surgeries (TS). 28 MR images of 18 patients were examined on 23 days to 1708 days after TS. After the epidural transplantation of the homologous fatty tissue in dog, its T_1 relaxation time (T_1) was signigicantly prolonged (p＜0.001) and its T_2 relaxation time (T_2) was significantly shorted (p＜0.001). The signal intensity of the homograft after TS gradually decreased in either T_1-weighted or T_2-weighted image. Over one year after TS, the homografts showed low siginal intensities in either T_1-weighted or T_2-weighted image. Therefore they were differentiated from the pituitary glands and adenomas. The histopathological studies showed the epidual transplanted homografts had many mycrophages, liquefaction and were finally replaced connective tissues. From this study, it was concluded that the homograft fat can be differentiated from the pituitary gland and adenoma by MR image and changes of T_1 and T_2 may be induced by increasing of free water, macrophage and fibrosis.