Intraoperative magnetic resonance imaging during surgery for pituitary adenomas: pros and cons.

Surgery for pituitary adenomas still remains a mainstay in their treatment, despite all advances in sophisticated medical treatments and radiotherapy. Total tumor excision is often attempted, but there are limitations in the intraoperative assessment of the radicalism of tumor resection by the neurosurgeon. Standard postoperative imaging is usually performed with a few months delay from the surgical intervention. The purpose of this report is to review briefly the facilities and kinds of intraoperative magnetic resonance imaging for all physician and surgeons involved in the management of pituitary adenomas on the basis of current literature. To date, there are several low- and high-field magnetic resonance imaging systems available for intraoperative use and depiction of the extent of tumor removal during surgery. Recovery of vision and the morphological result of surgery can be largely predicted from the intraoperative images. A variety of studies document that depiction of residual tumor allows targeted attack of the remnant and extent the resection. Intraoperative magnetic resonance imaging offers an immediate feedback to the surgeon and is a perfect quality control for pituitary surgery. It is also used as a basis of datasets for intraoperative navigation which is particularly useful in any kind of anatomical variations and repeat operations in which primary surgery has distorted the normal anatomy. However, setting up the technology is expensive and some systems even require extensive remodeling of the operation theatre. Intraoperative imaging prolongs the operation, but may also depict evolving problems, such as hematomas in the tumor cavity. There are several artifacts in intraoperative MR images possible that must be considered. The procedures are not associated with an increased complication rate.