Described is a dynamic phantom. The phantom comprises a body having a front, a back, and an internal cavity between the front and the back, the body having a movable chest wall. The phantom also comprises a first motion mechanism that is actuated to move the chest wall to thereby move the front relative to the back of the body. The phantom also comprises a moveable organ member supported within the internal cavity that is caused to move relative to the body by a second motion mechanism. The phantom also comprises a drive source for driving the first and second motion mechanisms, wherein the first and second motion mechanisms move the chest wall and the moveable organ member to substantially represent their movement in a human body.