A previously healthy 44-year-old woman presented with intermittent episodes of bilateral upper limb numbness over 8 months with worsening symptoms associated with bilateral hand clumsiness and unsteady gait in the past month. She denied having any sphincter dysfunction. Her neurological function status was Nurick grade III. Cervical MRI scan was prescribed for detecting possible pathological conditions.
The patient's general physical examination was unremarkable. The pathologic findings on neurological examination were as follows: spastic quadriparesis that was most prominent on the left side, hypoesthesia mainly between C5 and T1, exaggerated deep tendon reflexes on the left side limbs, and a positive Babinski's sign in the left foot. There was reduced vibration and position sense in the left toe and ankle. Rectal tone and sensation were both normal. The patient also exhibited Romberg's sign and spastic-ataxic type gait disturbances. T2-weighted MRI examination of her cervical spine revealed a hyperintense C2-C5 intramedullary lesion with spinal cord expansion and edema extending rostrally into the medulla and caudally to the thoracic spinal cord (Figure 1). There was no contrast enhancement. We therefore decided to perform microsurgical tumor resection with the aid of a unique imaging protocol that allowed application of high-field ioMRI in combination with neurophysiological monitoring of somatosensory and motor-evoked potentials (MEPs). For the ioMRI T2WI-detected hyperintensity zone, the area was first explored under microscopic guidance. Following tumor confirmation, the resection was performed under stringent control of MEP neuromonitoring. The design prevented us from mistaking operation-induced hyperintensities as tumor masses. Our approach, with enhanced safety measures for patient protection, augmented surgical completeness of IMSCT resection in a multiple operating room (OR) setting that did not have a designated ioMRI operation suite.
At Bahcesehir University, Goztepe Medical Park Hospital, any of the six operating rooms in our surgical theater is designed to have access to the ioMRI (MRW450) system between surgical procedures or stages (Figure 2). Implementation of this novel concept permits that each OR can be assigned for its routine operations with prephased access to ioMRI assistance. Furthermore, the use of MR compatible headrest-head coil unit (General Electric Healthcare, Chi-cago, IL, USA) allows the patient to be imaged directly at planned procedure time point. The surgical tables (Maquet GmbH, Rastatt, Germany) used in our OR are adapted to be interchangeable with an MRI compatible transfer table that enables transient transportation of patient to MRI gantry under general anesthesia. In the present case, the patient was positioned and fixed in prone position for posterior midline approach to the cervical intramedullary region. The thorax and pelvis of the patient were supported by silicon pads. At time of transfer, the operative field was covered with a new drape, coverings beyond the operative field were removed, and the patient was transferred through the connection door to the ioMRI system. Then, the MRI head coil was mounted on the headrest. After ioMRI scanning, the patient was brought back to the operating table, with a new drape being placed on the operative site followed by a general redraping. Images were processed and displayed immediately after acquisition in the monitoring room (Figure 3). Each step was controlled manually, and the members of the surgical team (ie, the primary surgeon and assistant surgeon, anesthesiologist, and radiologist) supervised the transfer to ensure patient safety. The primary neurosurgeon and radiologist interpreted the ioMRI results before refinement microsurgery was performed to ensure a complete removal of the neoplastic mass (Figure 3; Supplementary video).
The surgically removed tumoral tissue was preserved in The Bahcesehir University Tissue Bank (BUTB). BUTB maintains a tissue database with links to our general clinicopathological data storage. The tissue sample was snap-frozen in liquid nitrogen immediately after surgical removal and subsequently transferred from the OR to the tissue bank's liquid nitrogen bank for long-term storage and future analytical studies.