Buying an MRI machine is a tough task for any hospital or diagnostic centre. The most important thing which needs to be considered is the technical evaluation of different machines. Should one buy a permanent magnet or a superconducting magnet? In superconducting magnets whether one should go for 1.5 Tesla or 3 Tesla machine. Should one buy a refurbished machine or go for a new machine? These are some of the considerations which any hospital owner has to consider while evaluating different machines. When it comes to technical evaluation one has to consider things like Gradient Strength and Slew Rate.