What should be done to reduce pressure in an MRI scan room during a quench if a patient is present?

The correct approach to reducing pressure in an MRI scan room during a quench, if a patient is present, is to open the door to zone 4. This action allows the rapid release of helium gas from the magnet into an area where it's permitted to disperse safely. During a quench, the supercooled helium used to cool the magnet can vaporize and create an increase in pressure due to the release of gas. Opening the door connects the scan room (zone 3) to a less restricted area (zone 4), facilitating the safe venting of gas and helping to stabilize the environment for both the patient and the staff.

Breaking a window is not a standard procedure and could introduce additional hazards and risks, such as glass shattering or injury. Waiting for 20 minutes may not be practical or safe, as the pressure could remain elevated for an extended period, posing a risk to anyone present. Drilling a hole into the wall is also inappropriate due to the potential for structural damage and lack of control over the venting process.

Opening the door effectively minimizes risks associated with increased pressure and allows atmospheric pressure to return to normal more quickly, which is crucial for maintaining a safe environment during a quench event.