Question

According to the UK Medicine and Healthcare products Regulatory Agency (MHRA) Safety Guidelines for Magnetic Resonance Imaging Equipment in Clinical Use (2007): 

a. The magnetic resonance (MR) controlled area contains the 0.5 mT (5 Gauss) field contour 

b. The inner MR controlled area contains the 5 mT (50 Gauss) field contour 

c. Ferromagnetic objects are allowed in the MR controlled area 

d. Persons with pacemakers can access the MR controlled area but not the inner MR controlled area 

e. Only equipment marked as ‘MR Safe’ can be brought into the inner MR controlled area 

Answer 1

a. True. 

b. False. This contains the 3 mT (30 Gauss) field contour. 

c. True. However, they cannot be brought into the inner MR controlled area where a projectile hazard exists. Good practice would indicate that ferromagnetic objects are also kept out of the controlled area. 

d. False. Patients with pacemakers are not allowed to be exposed to a magnetic field stronger than 0.5 mT (MR controlled area; note this can extend beyond the actual MR room). This may change in the future given the availability of MRI-compatible pacemakers. 

e. False. Equipment marked as ‘MR Conditional’ can also be brought into the inner controlled area, providing the specified conditions are met.