Objective To review the preliminary clinical experience with dual lOOm intraoperative high-field-strength magnetic resonance(MR)imaging suite with a movable magnet in pituitary adenomas operation through transsphenoidal approach.Methods From February to July 2009,28 patients(mean age:46.60±8.65 years old),of pituitary adenoma were operated through transsphenoidal approach and examined intraoperatively with a movable 1.5T MR magnet.The mean tumor size was 3.37±0.65 cm (ranged from 1.60 to 7.27 cm).A navigation microscope in combination with a ceiling-mounted navigation system enabled microscope-based neuronavigation in 14 cases.Neuroendoscope was also used in 16 cases.Results 27 operations through transnaso-sphenoidal approach were performed.Transorosphenoidal approach Was performed in one patient.In 13 of 28 patients,intraoperative MR imaging had revealed residual lesions and resulted in the change of the SUrgical strategy.Fuaher resection of tumors was not performed in three cavernous sinus invasion cases because of ICA encasemenL The further total resection was achieved in the other 10 cases.There Was no intraoperative MR related safety issue or accident in this study.Conclusions Dual room intraoperative high-field-strength magnetic resonance(MR)imaging suite with a movable magnet could provid high-quality intraoperative MR images and valuable information of tumor resection which are helpful for intraoperative modification of the surgical strategy.It could be very helpful to maximize the resection of pituitary adenomas and minimize the injury to neurological function.