MRSO Cheat Sheet 2026

The 30 highest-yield MRSO facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Ferromagnetic objects can be pulled into the MRI scanner with great force, creating a significant safety hazard, so they must be kept out of the scan room. → To prevent potential injury or malfunction of the implants due to the magnetic field
2. What is the most common cause of serious RF-related thermal injuries (burns) to patients in the MRI environment? → Formation of a conductive loop by skin contact or cables.
3. What is the primary role of a Magnetic Resonance Safety Officer (MRSO)? → To ensure the safety of patients, staff, and equipment in the MRI environment
4. Which patient condition represents the most significant risk factor for developing Nephrogenic Systemic Fibrosis (NSF)? → Acute kidney injury or severe chronic kidney disease
5. What is the primary safety concern related to the static magnetic field (B0) in MRI? → Projectile hazards from ferromagnetic objects
6. What is the primary function of the quench pipe or vent? → To safely vent helium gas outside the building during a quench
7. Which of the following items would most likely be labeled 'MR Safe'? → A non-ferromagnetic, non-conductive plastic basin
8. The visual phenomenon of seeing flashes of light, known as magnetophosphenes, is caused by the time-varying magnetic fields stimulating which part of the body? → The retina
9. What action should be taken if a ferromagnetic object is accidentally brought into the MRI room? → Immediately remove the object if it is safe to do so
10. How often should safety training be provided to staff working in an MRI environment? → Annually
11. In the event of a small liquid nitrogen spill on the floor in a well-ventilated service area, what is the correct procedure? → Evacuate the immediate area and allow it to evaporate naturally
12. GBCAs are classified into groups based on risk. Which group has been associated with the vast majority of documented NSF cases? → Group I (Linear agents)
13. What is the minimum required Personal Protective Equipment (PPE) when handling or transferring liquid cryogens? → Insulated gloves, a face shield/goggles, and closed-toe shoes
14. Which zone in an MRI facility is considered the most restrictive in terms of safety? → Zone IV
15. According to the ACR Manual on Contrast Media, for which group of patients is a recent eGFR assessment most critical before administering a GBCA? → Patients with a history of hypertension, diabetes, or age > 60 years
16. What should be the first step if a risk is identified during an MRI procedure? → Stop the procedure immediately if it poses an immediate danger
17. According to ACR guidelines, what is the recommended policy for pregnant healthcare personnel regarding access to the MRI scan room (Zone IV)? → They are permitted in Zone IV but should exit the room during active data acquisition.
18. The translational force on a ferromagnetic object is greatest where the... → spatial gradient of the magnetic field is maximal.
19. An unmarked, metallic tool is found in a clinical area. How should it be treated with respect to MR safety? → It must be assumed to be MR Unsafe until proven otherwise
20. According to IEC 60601-2-33, what is the whole-body averaged Specific Absorption Rate (SAR) limit for the 'Normal Operating Mode'? → 2.0 W/kg
21. In MRI safety, what does the 'slew rate' of a gradient system refer to? → The speed at which the gradient reaches its maximum amplitude.
22. The primary safety concerns for the fetus during an MRI examination are related to which two physical phenomena? → RF energy deposition and acoustic noise.
23. Prior to MRI, MR-conditional pacemakers are typically reprogrammed to which pacing mode to prevent inappropriate pacing inhibition? → Asynchronous (AOO/VOO/DOO) pacing mode
24. According to IEC 60601-2-33 and FDA guidance, hearing protection should be provided to all patients when the sound pressure level is expected to exceed: → 99 dBA
25. What is the primary physical mechanism responsible for the loud acoustic noise generated during an MRI scan? → Lorentz forces on the gradient coils
26. Which whole-body average SAR limit is most commonly specified in MR-conditional pacemaker labeling to reduce the risk of RF-induced lead tip heating? → 2.0 W/kg
27. Which of the following is considered a critical aspect of MRI safety? → The strength of the magnetic field
28. Which mechanism is the primary source of cardiac injury risk from MRI in patients with implanted pacemaker leads? → RF-induced resistive heating concentrated at the electrode-tissue interface
29. Where is the proper location for storing a dewar of liquid helium? → In a well-ventilated area, away from patient care areas
30. What is the principle behind using a waveguide for penetrations through an RF shield? → It acts as a high-pass filter, attenuating frequencies in the MRI operational range.