Data viva — MRI, laser and radiation safety

Stimulus

A diagram shows the four concentric MRI zones of a radiology suite (Zone I the public area, Zone II the screening intake, Zone III the controlled-access staff corridor, Zone IV the scanner room with the quench button on its wall) alongside an ALARA triangle with each side labelled Time, Distance and Shielding. Describe the four zones and the hazard controlled at each boundary, then explain each side of the ALARA triangle and the physical law that underpins the distance principle.