The Research Of The High-field IMRI’s Application In Transnasalsphenoidal Surgery For Pituitary Adenomas

Objective To discuss the application of the high-field intraoperative magnetic resonance imaging (iMRI) associated with neuronavigation system in transnasalsphenoidal surgery for pituitary adenomas.Methods38pituitary adenomas were resected via nasal-sphenoidal approach with assistance of the GE Signa1.5T intraoperative magnetic resonance system associated with Brain LAB neuronavigation system. And iMRI scannings were performed to make sure that whether the rececting extend of the adenomas need expanding or not. For the adenomas which were totally recected or recected to achieve the pre-operative purpose, then finished the operation. If the adenomas remained, and needed further resecting, then expanded the resecting extent and performed iMRI scannings. Repeated the process above until the tumors were totally resected. The clinical materials, iMRI’s imaging quality and its influence on the surgical process and results were analyzed.Results The times of intraoperative scanning ranged from2to3per patient, averaging2.11+0.41times. The scanning time was3-5min, and adding the packaging and transporting process, the whole procedure lasted15～20minutes. Posing the position, fixing the head rest and navigation registering cost32-40min in all. So the total operation time was extended to47-60min, averaging51.20+0.66min. The iMRI was used to scanning and collecting pictures, and showed that11cases were revealed residual tumor tissue existing.8of the11continued to be totally removed under new navigation data after updating the neuronavigation plans(without a new registeration). while other3cases were sub totally resected because the adenomas were tenacious and adhered closely to the significant anatomy structures surrounding and had achieved the planed resecting extent. Finally, with the use of this iMRI system, the totally resected rate(TRR) of the adenomas increased from71.05%(27/38) to92.11%(35/38), improved21.06%(8/38), X2=4.290,P=0.018, the statistics discrepancy was significant. There was no iMRI related complication happened.Conclusion The application of iMRI-based neuronavigation technology in transnasalsphenoidal operations for pituitary adenomas provides objective evidence for the guidance of surgical procedure and the real time judgment of surgical results, which leads to higher TRR and avoiding accuracy lost caused by brain-drift in transnasalsphenoidal operations.