POSTOPERATIVE FINDINGS IN MRI FOLLOWING P ITUITARY SURGERY

36 patients with pituitary adenomas were examined via MRI to describe physiological changes and to visualise a residual tumour. Pre- and pos toperative examinations included T1- and T2-weighted SE sequences. T1- weighted images were obtained in sagittal and coronal orientation pre- and post-Gd-DTPA application and T2-weighted images in coronal orient ation. In 12 cases a residual tumour was found. Its signal intensity a nd contrast enhancement were similar to those of the primary tumour. I mplanted material could be distinguished by localisation, decrease in volume and different signal intensity. The behaviour of contrast enhan cement was helpful, since implanted material showed a rim enhancement. In our experience a sensitive imaging protocol in the follow-up of op erated pituitary adenomas would be an early examination three months p ostoperatively followed by a control examination after one year. Infor mation on the size and localisation of the primary tumour and the perf ormed operative procedure is essential.