One of the questions addressed before anyone gets an MRI scan is whether the patient has any sort of implant or device or foreign body that may be adversely affected by the magnetic fields. Sounds simple, doesn’t it? Don’t we just look at a list of those items that would contraindicate an MRI scan?
Well, it is not so simple. Dr. Emanuel Kanal, director of MR services at University of Pittsburgh Medical Center and a well-known expert on MRI safety issues, has developed the MR Safety Implant Risk Assessment app on the IOS (iPhone) platform to address the multiple factors involved. A recent interview with him on AuntMinnie.com, the popular radiology website, discussed the details and intricacies of the app (Ridley 2016).
Factors affecting the safety during MRI include not only the type of implant but also its location, the type of MRI scan being done, the part of the body being imaged, the strength of the magnet and other issues of configuration of the MRI machine, and other considerations such as the location of the various energy sources relative to the patient’s location in the MRI suite. Kamal notes that what is safe in one system may not be safe in another. Moreover, a patient might safely have one part of the body imaged by MRI but not another. Importantly, some patients may be being denied potentially helpful MRI scanning that could be safely performed given the correct type of study and equipment.
The intended audience for the app is MR technologists, radiologists, or MR physicists and it requires technical knowledge about MRI. Kamal describes the app as a teaching tool in addition to its practical utility in determining whether a patient can be safely imaged by MR. Kamal, who is also a licensed pilot, describes the checklist format that forces the user to consider all the potential safety concerns before concluding that the patient may have the MR study safely performed.
The interview is worth your reading and you should make sure that those involved in your MRI unit know about the nature and availability of the app. But the interview was enlightening even for those of us lacking the technical MR expertise. As a neurologist, I highly suspect after reading it that there have been instances where I referred patients for alternative imaging modalities when an MRI actually could have been performed safely.
Speaking of safety in the MRI suite, we should also note that a coalition of societies and organizations dealing with MRI has proposed a delineation of responsibilities for the management of MRI facilities (Calamante 2016).
Some of our prior columns on patient safety issues related to MRI:
Ridley EL. Mobile App Spotlight: Kanal's MR safety implant risk tool. AuntMinnie.com 2016; August 24, 2016
Apple iTunes store. Kanal's MR Safety Implant Risk Assessment (app).
Calamante F, Ittermann B, Kanal E, The Inter-Society Working Group on MR Safety and Norris D. Recommended responsibilities for management of MR safety. JMRI 2016; Early View 3 Jun 2016