NOT DETERMINED

Additional Manufacturer Narrative

THE INVESTIGATION IS STILL ONGOING FOR THIS EVENT. WHEN THE INVESTIGATION IS COMPLETE A FOLLOW-UP REPORT WILL BE SENT TO THE FDA.

Description of Event or Problem

PHILIPS RECEIVED A REPORT FROM A CUSTOMER RELATED TO A PATIENT HEATING INCIDENT WITH AN ACHIEVA 1.5T MR SYSTEM. A FEMALE PATIENT WAS EXAMINED WITH THE SENSE NV COIL AND SENSE SPINE COIL AND SUSTAINED A 2ND TO 3RD DEGREE HEATING INJURY ON THE LEFT LOWER BACK.

Additional Manufacturer Narrative

THE COIL WAS RETURNED FROM THE CUSTOMER AND AN ENGINEERING EVALUATION WAS CONDUCTED. ENGINEERING CONDUCTED EXTERNAL AND INTERNAL VISUAL INSPECTIONS WITH NO DEFECTS OR INDICATION OF BURN FOUND. SYSTEM TESTS WERE CONDUCTED TO EMULATE THE FAULT CONDITION. A HEAT TEST WAS CONDUCTED. THE INTERACTION OF THE COIL WITH THE BODY COIL WAS MEASURED AND THE WORST CASE POSITION WAS NOTED. THE TOTAL SCAN TIME DURING THE CLINICAL SCAN WAS ~1 HOUR; THEREFORE, THE HEAT TEST WAS PERFORMED FOR 1 HOUR. AFTER THE HEAT TEST THE NV AND SPINE COIL WERE EVALUATED USING AN IR CAMERA. THE SURFACE TEMPERATURE OF THE COIL EXCEEDED THE MAXIMUM ALLOWABLE TEMPERATURE OF 41 C (PATIENT CONTACT)/51 C (PATIENT CASUAL CONTACT) AROUND THE AREA THAT THE PATIENT BURN WAS REPORTED. THE COIL WAS THOROUGHLY CHECKED ON THE BENCH FOR SIGNS OF EXCESSIVE HEATING. NONE WERE OBSERVED AND THE COIL MEASUREMENTS SEEMED TO BE WITHIN SPECIFICATION. PROBABLE CAUSE FOR OVERHEAT: THE PATIENT WAS PUT THROUGH MULTIPLE HIGH SAR SCANS WITH POWERS RANGING FROM 6.6 KW TO 16 KW WITH MOST SCANS BEING AROUND 15 KW. THIS IS NOT RECOMMENDED. THOUGH THE SURFACE TEMPERATURES OF THE COIL DID GO BEYOND 51 C AT THE PATIENT CASUAL CONTACT SURFACE IT IS NOT PLAUSIBLE FOR A 66 C SURFACE TO CAUSE 3RD DEGREE BURNS UNLESS THE PATIENT WAS LAYING DIRECTLY ON THE HOT SURFACE. THE B1 TESTS DID NOT REVEAL ANY DANGEROUS CABLE CURRENTS THAT MIGHT HAVE CAUSED RF BURNS. THOUGH THERE WERE A FEW MISTUNED DECOUPLERS IN THE COIL, IT WAS SHOWN THAT THE MISTUNED DECOUPLERS DID NOT CONTRIBUTE TO THE TEMPERATURE RAISE AS A SIMILAR TEMPERATURE RAISE WAS OBSERVED AFTER THE FAULT WAS FIXED. THE IFU INDICATES THAT CONSECUTIVE HIGH SAR SCANS SHOULD NOT BE PERFORMED. CONSECUTIVE HIGH SAR SCANS WITH DIRECT PATIENT CONTACT CAN RESULT IN A HARMFUL CONDITION. A PLAUSIBLE EXPLANATION FOR THE CAUSE OF THE INCIDENT COULD BE THAT THE PATIENT¿S BODY WAS IN CONTACT WITH THE TRANSMIT BODY COIL OR THAT THE CABLE WAS ROUTED UNDERNEATH THE PATIENT MAKING CONTACT. BOTH OF THESE CONDITIONS ARE MENTIONED AS SAFETY HAZARDS IN THE IFU. FROM THE ANALYSIS AND THE TESTS PERFORMED, THE FAULT CONDITION IS NOT REPRODUCIBLE.