Author: Michael A. Evans, MD – Ann & Robert H. Lurie Children’s Hospital of Chicago, Northwestern Feinberg School of Medicine
A 5-year-old child with a history of Williams syndrome presents for a cardiac magnetic resonance imaging (MRI) under general anesthesia. During induction of anesthesia, the patient has a cardiac arrest. A code is called, and pediatric advanced life support (PALS) is initiated. To which MRI Zone should the patient be evacuated to facilitate assistance in resuscitation?
Correct!
Wrong!
Question of the Week 334
The perioperative areas adjacent to the MRI scanner are divided into four zones: Zone 1, Zone 2, Zone 3, and Zone 4.
Zone 1 is open to unscreened patients and families. It typically consists of areas open to the general public that are outside of the MRI environment. Patients and families are not screened in Zone 1 and move freely and unsupervised.
Zone 2 is the interface between the publicly accessible and uncontrolled Zone 1 and the controlled Zones 3 and 4. Typically, preoperative evaluation, patient screening, and examination occur in Zone 2.
MRI Zone 3 requires personnel be screened prior to entry. Thus, it is most appropriate to move this patient to MRI Zone 2 while continuing resuscitation.
Zone 3 is physically restricted from the general public and non-MR personnel. It is demarcated/indicated as potentially hazardous, as there are static magnetic fields. The introduction of unscreened non-MR personnel or ferromagnetic materials/equipment can result in serious injury or death. It is important to note that the nature of magnetic fields being three-dimensional means Zone 3 may extend between floors in a hospital.
Zone 4 consists of the room that contains the MRI scanner. It is clearly labeled as hazardous due to the existence of strong magnetic fields.
Based on the American College of Radiology’s manual on MR safety, controlled site-access restriction to Zones III and IV must be maintained during resuscitation and other emergent situations for the protection of all involved. This access restriction is enforced by Zone 2 MRI personnel during a code event to protect non-screened personnel from being harmed.
Thus, in the event of cardiac or respiratory arrest in Zone 4, a patient should be evacuated to Zone 2 (or other predetermined area) that is outside the confines of Zones 3 and 4 as quickly and safely as possible while undergoing resuscitative efforts.
Quenching a superconductive magnet is not advised, as quenching the magnet to dissipate the magnetic field can take more than a minute. It could also introduce other hazards to Zone 4.
References
1. ACR Manual on MR Safety. https://www.acr.org/-/media/ACR/Files/Radiology-Safety/MR-Safety/Manual-on-MR-Safety.pdf . Accessed August 2, 2021. ACR COMMITTEE ON MR SAFETY. AMERICAN COLLEGE OF RADIOLOGY. 1891 Preston White Drive, Reston, VA 20191
2. Sammet S. Magnetic resonance safety. Abdom Radiol. 2016; 41(3): 444-451.
3. Expert Panel on MR Safety, Kanal E, Barkovich AJ, et al. ACR guidance document on MR safe practices: 2013. J Magn Reson Imaging. 2013; 37(3): 501-530. doi:10.1002/jmri.24011
Zone 1 is open to unscreened patients and families. It typically consists of areas open to the general public that are outside of the MRI environment. Patients and families are not screened in Zone 1 and move freely and unsupervised.
Zone 2 is the interface between the publicly accessible and uncontrolled Zone 1 and the controlled Zones 3 and 4. Typically, preoperative evaluation, patient screening, and examination occur in Zone 2.
MRI Zone 3 requires personnel be screened prior to entry. Thus, it is most appropriate to move this patient to MRI Zone 2 while continuing resuscitation.
Zone 3 is physically restricted from the general public and non-MR personnel. It is demarcated/indicated as potentially hazardous, as there are static magnetic fields. The introduction of unscreened non-MR personnel or ferromagnetic materials/equipment can result in serious injury or death. It is important to note that the nature of magnetic fields being three-dimensional means Zone 3 may extend between floors in a hospital.
Zone 4 consists of the room that contains the MRI scanner. It is clearly labeled as hazardous due to the existence of strong magnetic fields.
Based on the American College of Radiology’s manual on MR safety, controlled site-access restriction to Zones III and IV must be maintained during resuscitation and other emergent situations for the protection of all involved. This access restriction is enforced by Zone 2 MRI personnel during a code event to protect non-screened personnel from being harmed.
Thus, in the event of cardiac or respiratory arrest in Zone 4, a patient should be evacuated to Zone 2 (or other predetermined area) that is outside the confines of Zones 3 and 4 as quickly and safely as possible while undergoing resuscitative efforts.
Quenching a superconductive magnet is not advised, as quenching the magnet to dissipate the magnetic field can take more than a minute. It could also introduce other hazards to Zone 4.
References
1. ACR Manual on MR Safety. https://www.acr.org/-/media/ACR/Files/Radiology-Safety/MR-Safety/Manual-on-MR-Safety.pdf . Accessed August 2, 2021. ACR COMMITTEE ON MR SAFETY. AMERICAN COLLEGE OF RADIOLOGY. 1891 Preston White Drive, Reston, VA 20191
2. Sammet S. Magnetic resonance safety. Abdom Radiol. 2016; 41(3): 444-451.
3. Expert Panel on MR Safety, Kanal E, Barkovich AJ, et al. ACR guidance document on MR safe practices: 2013. J Magn Reson Imaging. 2013; 37(3): 501-530. doi:10.1002/jmri.24011
