This abstract is aimed at clinicians and researchers that are interested in performing minimally invasive neurosurgical procedures in a conventional MR suite. It is specifically relevant to sites performing deep brain stimulator (DBS ) implantations in an MR suite that does not fully meet operating room standards.The use of intraoperative MR methods for implanting DBS electrodes is on the rise [1]. This burrhole based procedure is conventionally performed in an operating room (OR) environment and is associated with hardware infection rates ranging from 2-10% [2,3]. The requirement that MR guided DBS implantations be performed in a fully compliant OR would greatly restrict the dissemination of this promising surgical approach. We therefore report on our incidence of hardware infections for DBS implantations performed in a diagnostic MR suite.MR guided DBS implantations were performed in a diagnostic MR suite over a ten year period. The MR suite featured a 1.5T MR system, suspended tile ceiling, vinyl flooring, painted drywall, and a number of wood veneer cabinets. The air supply was not HEPA filtered, had a slight positive pressure of 0.87 Pascal and provided 12.6 air exchanges/hour. This unfiltered air flow was directed away from the operative field. Sterile practices were followed, including wiping down all surfaces with germicidal disposable wipes prior to surgery. After cleaning, the room was considered sterile and personnel entering the suite had to wear surgical scrubs, cap and mask. Patients were prepped in a manner analogous to that performed in the OR and received a prophylactic dose of antibiotic (typically 1-2g cefazolin). The surgical team always included an experienced DBS surgeon, who was supported by scrub and circulating nurses with extensive OR experience. The surgical procedure has previously been described in detail but involved unilateral or bilateral burrholes and skull mounted trajectory guides. MR imaging was performed to identify the desired deep brain target, orient the trajectory guides and monitor the insertion process. Medtronic DBS electrodes were used for all studies. After the DBS electrode(s) were successfully positioned, the DBS leads were anchored to the skull and scalp closure occurred with conventional sutures and staples. The implanted pulse generator (IPG) and extender wire were placed in a separate surgical procedure 1-3 weeks later. Hardware infection occurring within 6 months of DBS implantation was attributed to the surgical procedure. Intraoperative microbial culture was performed in all subjects who underwent hardware removal for suspected infection.A total of 164 DBS procedures were performed, with a total of 272 electrodes implanted in 108 bilateral and 56 unilateral procedures. Patients ranged in age from 7-78 years (mean = 57±15 years) and included 141 Parkinsonian patients, 19 dystonia patients, 2 Tourette syndrome patients and 2 tremor disorder patients. A total of six (3.7%) hardware related infections occurred during this ten year enrollment period (Table 1). All infections occurred in PD patients undergoing bilateral electrode implantations. There was an important change in our clinical practice after our first 10 surgical procedures. In these early cases we did not have an MR compatible drill and thus the burrhole was prepared outside the magnet room in a separate sterile field. The patient was then transferred into the magnet suite, a new sterile field was created and the procedure performed. This technique was associated with two early infections that both presented within two weeks of surgery. Bacterial cultures indicated staphylococcus epidermis in one case and propionibacterium in the other. Both featured redness over the frontal incision site and required removal of all implanted hardware. A single sterile field approach was used for all subsequent procedures and this reduced the infection rate for our current surgical practice to 4/154 (2.6%). Bacterial cultures indicating either staphylococcus epidermis (n=2) or MSSA (n=2). Importantly, all infection symptoms in this subset of patients originated at the IPG site and not the frontal incision. This has led us to hypothesize that the source of these infections was not from the DBS electrode implantation, but rather the IPG implantation procedure that was performed 1-3 weeks later. Statistically, the chance of seeing no infections related to the DBS implantation procedure over these 154 procedures indicates that there is a >95% chance that our actual infection rate is <2%.Infection risk when implanting DBS electrodes in a diagnostic MR suite is comparable to that reported for DBS implanted in a regular OR. An experienced team following sterile practices similar to those utilized in a regular OR may be important in achieving an acceptable infection risk.