Managing SAR

According to the video, tissue heating during an MRI is primarily caused by which physical phenomenon?. Electric discharge. Magnetic induction. Static friction. Thermal conduction from the magnet bore.

What are the standard units used to measure Specific Absorption Rate (SAR)?. Watts per kilogram (W/kg). Joules per second (J/s). Tesla per minute (T/min). Degrees Celsius per hour (°C/hr).

In the IEC standards for whole-body SAR, what is the maximum limit for the "Normal Operating Mode"?. 1.0 W/kg. 4.0 W/kg. 3.2 W/kg. 2.0 W/kg.

What physiological expectation is associated with the "First Level Controlled Mode" for whole-body SAR (>2.0 W/kg to 4.0 W/kg)?. No physiological stress is expected. Physiologic stress is possible. Immediate tissue damage is guaranteed. The patient will lose consciousness.

Which of the following environmental factors primarily influences a patient's ability to cool themselves during an MRI?. Magnetic field homogeneity. Room lighting levels. Relative humidity of the room. The type of contrast media used.

Which medical condition is specifically mentioned by Dr. Frank Shellock as affecting an individual's ability to tolerate a thermal challenge?. Color blindness. Cardiovascular disease. Astigmatism. Lactose intolerance.

How does increasing the Repetition Time (TR) affect SAR?. It increases SAR. It reduces SAR. It has no effect on SAR. It only affects image contrast, not safety.

Which of these is a practical management strategy to reduce patient heating between scans?. Running every sequence back-to-back without delays. Turning off the bore fan to reduce noise. Using the minimum possible TR for all slices. Pausing briefly between sequences.

Why should you avoid wrapping an MRI patient in heavy or heated blankets during the scan?. They cause motion artifacts. They interfere with the body's ability to dissipate heat. They create shadows in the MRI image. They are too expensive to clean.

Which pulse sequence type is specifically mentioned as tending to have a higher SAR?. Fast Spin Echo (Turbo Spin Echo). Conventional Spin Echo. Low flip-angle Gradient Echo. Localizer / Scout scans.