3 T ioMRI: the Istanbul experience

Intraoperative imaging technologies have improved surgical results in glioma and pituitary adenoma surgeries. With improvements and refinements 3T intraoperative MRI systems offer a potential of further improving these results. Hereby we describe the equipment and technique of a cost-effective shared-resource 3-T ultra-high field intraoperative magnetic resonance imaging system and report our continuing experience on surgical tumor resection. A description of the facility design and equipment are given along with examples from our experience on low-grade gliomas and transsphenoidal surgeries. Our facility based on the twin room concept and uses a 3-T Siemens Trio (Siemens, Erlangen, Germany) scanner. The unit consists of adjacent but independent MRI and operative suites, which are connected by a wide door for ioMRI procedure but are used as conventional MRI and operative units. Rigid head fixation during neurosurgery is achieved with a custom designed 5 pin head-rest which also combines a 4+4 channel head coil. Operation is performed using regular non-MRI compatible equipment and the patient is transferred to the MRI during the procedure using a custom designed floating table. Advanced sequences such as diffusion weighted and diffusion tensor imaging, MR angiography, MR venography, MR spectroscopy can be performed with no changes in the setup and result in image quality comparable to outpatient scans. The intraoperative 3-T ultra high field MRI unit with the twin room concept permits both diagnostic outpatient imaging and image guided surgery in the same setting and is a cost effective solution to afford a highly capable ioMRI system.