Normal heart.

 

Learning points The image of the heart was obtained in diastole when the heart was relaxed and fully filled with blood before pumping.  The size of the heart is to scale. The old adage of your heart is as big as your fist is more consistent with an empty heart than a heart that is pumping which normally can get more than twice the size of a fist when fully filled. CT does not clearly capture the fine movements of the valves and therefore they do not transfer to the printed model well.