gms | German Medical Science

Objective: From April 2002 until July 2008 we were able to perform more than 1200 neurosurgical procedures using intraoperative high field magnetic resonance (MR) imaging. The majority of examinations were carried out in adults. In this study we summarize our experience in pediatric neurosurgery.

Methods: Imaging was performed using a 1.5 -Tesla Magnetom Sonata Maestro Class scanner (Siemens AG, Medical Solutions), which was placed in a radiofrequency-shielded operating theatre. The principal surgical position is with the patient’s head placed at the 5-G line allowing surgery with standard instruments and additional neuronavigational guidance. For scanning, the table is turned for 160 degrees into the scanner manually for safety reasons. Imaging is performed with an 8-channel coil integrated into the head holder allowing parallel imaging and automatic patient registration.

Results: Intraoperative high field MR Imaging could be performed in 66 pediatric cases in 60 patients (male 28, female 32, age ranging between 2 and 17 years). We did not encounter any problems with the MR-compatible head fixation. Intraoperative imaging depicted no hematoma caused by the pin fixation. There was no additional morbidity directly attributable to intraoperative imaging. However, we had one case of postoperative meningitis, and in two patients rhinoliquorrhoea occurred so that transsphenoidal re-operation was necessary. In summary we performed 29 craniotomies (pediatric brain tumors, vascular malformations, non-lesional and lesional epilepsies), 20 transsphenoidal approaches (pituitary adenomas, craniopharyngiomas) and 17 burr hole procedures for cyst drainage, catheter placement or frameless stereotactic biopsies. In 34.8 % of all procedures intraoperative imaging resulted into an immediate change of surgical strategy, i.e. further tumor resection or adjustment of a catheter.

Conclusions: Intraoperative high field MR imaging is an effective and safe procedure. It serves as an intraoperative quality control documenting the effects of surgery, e.g. the extent of a resection. Besides its most essential application in brain tumors, it also proved to be particularly helpful in children undergoing complicated catheter placements for cyst drainage, as well as in pituitary and epilepsy surgery.