Computerised tomography.
CT scan ...
A sort of X-ray where the computer takes pictures in different planes, like cutting the body up into slices. Then the computer re-assembles them, and the radiologist can look at the body from various angles and different the soft tissues from the bones and fluid.
Like an MRI really, but a different technology. There are some imaging experts on this forum, so I trust they will explain this in better detail to you.
