Magnet Quench

What is a "quench" in a superconducting MRI magnet?. The process of cooling the magnet with liquid nitrogen. A rapid loss of superconductivity that causes liquid helium to boil off and the magnetic field to dissipate. The automatic cleaning of the patient table. A software update that improves image quality.

Which of the following is a primary safety risk if helium gas fills the scan room during a quench?. Excessive radiation exposure. Immediate hearing loss from the "popping" sound. Asphyxiation due to helium displacing oxygen. The patient’s skin turning blue from the cold gas.

Liquid helium expands to approximately 750 to 1. This means 1 liter of liquid helium becomes how many liters of gas?. 75 liters. 750 liters. 7,500 liters. 75,000 liters.

Why might personnel be unable to open an inward-swinging scan room door during a quench?. The magnetic field locks the door electronically. The rapidly expanding helium gas creates massive positive pressure inside the room. The helium freezes the door hinges instantly. The door handle becomes too slippery to turn.

What is the main reason quenching the magnet should NOT be the first choice in the event of a fire?. It is too expensive for the hospital. Helium gas is highly flammable. The cold helium can liquefy the atmosphere, creating concentrated liquid oxygen which is a major fire hazard. It takes too long for the magnetic field to drop.

If the primary ventilation system fails during a quench and the door cannot be opened, what is a recommended emergency action?. Wait for the helium to dissipate naturally through the vents. Break the scanning room window to equalize pressure. Try to suck the helium out with a vacuum cleaner. Pour water under the door to seal the room.

Who should be the only individual authorized to make the decision to quench a magnet?. The first firefighter on the scene. Hospital security guards. Level 2 MR personnel (trained MRI staff). The patient’s family members.

What is the function of the "Emergency Power Off" (EPO) button?. It quenches the magnet immediately. It turns off the liquid helium pump. It removes electrical power from all electronics in the scan room but leaves the magnet ON. It unlocks the doors to the entire hospital.

What physical effect can a sudden pressure change during a quench have on a patient or staff member's body?. It can cause permanent blindness. It can lead to a ruptured eardrum. It causes the teeth to become brittle. It increases the patient's heart rate by 50%.

How often should quench pipes and ductwork be inspected to ensure they are open and intact?. Once every 10 years. Only after a quench occurred. Annually (once a year). Every time the scanner is used.