An MRI apparatus is provided. The MRI apparatus includes a main magnet
(12) for generating a main magnetic field in an examination region, a
plurality of gradient magnets (16) for generating magnetic field
gradients in the main magnetic field, a radio frequency coil (22) for
transmitting radio frequency signals into the examination region and
exciting magnetic resonance in a subject disposed therein, and a radio
frequency coil for receiving the magnetic resonance signals from the
subject. The MRI apparatus also includes subject support (52) for
supporting the subject, a position controller (60) for controlling the
position of the subject support within the examination region, and a
position encoder (53) for directly measuring the position of the subject
support.