Implementation of a ferromagnetic detection system in a clinical MRI setting

•Ferromagnetic detection system sensitivity in this study was 100%.•Ferromagnetic detection system specificity in this study was 98%.•The additional screening procedure had little impact on throughput ie additional time taken was minimal.•Staff training, technique and compliance is important in implementing the screening procedures.•The ferromagnetic detection system identified objects that may have demonstrated projectile, heating or artefact effects.

PurposeTo evaluate the implementation of a ferromagnetic detection system (FMDS) into a clinical MRI setting.Materials and methodsOne thousand patients were considered for MRI safety screening using an FMDS. Equipment used was a Ferroguard® Screener (Metrasens Ltd, Malvern, Worcestershire, UK). Fully gowned patients rotated 360° in front of the FMDS in a standardized manner following traditional MRI screening methods (the use of a written questionnaire (Fig. B.1) and verbal interview.ResultsFinal results included 1032 individual screening events performed in 977 patients. There were 922 (94%) initial passes using the FMDS; 34 (4%) failed initial screens but passed a subsequent screen; 21 (2%) failed the initial and subsequent screens. Thus, including all screening events (n = 1032), there were 956 (93%) true negatives (TN); 21 (2%) false positives (FP) and 55 (5%) true positives (TP). No false negatives (FN) were recorded. Therefore, sensitivity was 100% and specificity was 98%.ConclusionImplementation and correct usage of an FMDS proved to increase safety within a clinical MRI environment by alerting staff to ferromagnetic items or implants not identified using traditional MRI screening methods. An FMDS should be used as an adjunct to these methods. The information in this study pertains to the specific equipment used in this investigation.