A method of maintaining a constant iso-center point, while dynamically changing an area of interest during an imaging procedure is provided. The method comprises: allowing a user to move from an initial area of interest to new area of interest by allowing permissible axes motions； dynamically calculating the iso-center point while moving from the initial area of interest to the new area of interest as a function of relative distance between the initial area of interest and the new area of interest and as a function of parameters indicating relative motion of permissible axes； identifying the new area of interest by using at least one permissible axis motion； and calculating the iso-center point at the new area of interest after locking all the permissible axes motions except table tilt axis movement.
