Author: Chris Beasley, Ngara Linda Bird, Flora Ivanova, Erin B. Macdonald, Lauren M. Neldner, Beth Reed, Scott H. Robertson 👨🔬
Affiliation: School of Medicine, Duke University, Duke University, Duke University Health System 🌍
Purpose: To develop a hands-on, data-driven educational program to improve MRI technologists' understanding and effective use of ferromagnetic detecting (FMD) wands.
Methods: A 30-minute interactive educational program was developed to teach MRI technologists how to effectively use FMDs to inform MRI safety decisions. Learners used a CDIA PD240CH ferromagnetic wand to detect ferrous and non-ferrous metal objects. The training involved two separate tasks: 1. Characterize size/distance performance of FMDs: The maximum detection distance for each of the FMD sensitivity modes was measured for objects of various composition and size that may be encountered clinically. To measure this distance, we moved the FMD slowly toward the object until detection occurred. 2. Hands-on FMD training: Technologists practiced using the wand in simulated screening scenarios. Ferrous, non-ferrous, implanted, and external objects were used to illustrate common limitations and misperceptions associated with FMDs. Pre- and post-training assessments were used to evaluate the effectiveness of the educational program.
Results: Not all metallic objects were detected by the FMD at clinically relevant distances. Larger objects could be detected at further distances than smaller objects. Objects with long length along the direction perpendicular to the FMD face were more readily detected. The sensitivity modes of the FMD provided the ability to accurately distinguish between ferrous and non-ferrous metals.
Conclusion: As supported by the ACR, FMDs are valuable MRI safety tools to supplement MRI screening, but only when used with an understanding of their limitations. FMDs can miss small objects, not detect distant objects, or identify small ferrous objects that pose minimal risk. Technologists must use their expertise to interpret and apply this knowledge as part of a full risk assessment.