OBJECTIVESTo review the preliminary clinical experience with high-field-strength intraoperative magnetic resonance imaging (iMRI) suite with neuronavigation system in the pituitary adenoma operation with transsphenoidal approach.

METHODSFrom March 2009 to December 2010, 31 patients [range, 29 - 76 years, mean age (47 ± 11) years]of pituitary adenoma were operated with transsphenoidal approach and intraoperatively with a movable 1.5 T high-field-strength iMRI suite in combination with neuronavigation system. Tumor size was 1.8 - 7.3 cm, mean (3.5 ± 1.2) cm. Twenty-five cases were non-functional pituitary adenoma, 4 cases were prolactin-secreting pituitary adenoma, 2 cases were growth hormone-secreting pituitary adenoma. Thirty patients' resection with transnasal transsphenoidal approach were performed, one patient with transoral transsphenoidal approach was performed.

RESULTSIn 12 cases of 30 patients who planed to totally remove tumor, iMRI had revealed residual lesions and resulted in the change of the surgical strategy, 2 invasive cavernous sinus cases no further resection of the tumor because of internal carotid artery encasement, the other 10 cases resected further, eventually. Finally, 8 cases were totally removed. The ratio of total removal tumor was enhanced to 86.7% (26/30) from 60.0% (18/30). There was no perioperative mortality.

CONCLUSIONSHigh-field-strength iMRI suite with neuronavigation system provides valuable information of tumor resection that allows intraoperative modification of the surgical strategy. It could be very helpful to maximize the resection of the pituitary adenoma and minimize the injury to neurological function.