CAT stands for "computerized axial tomography." Translated, that means a scanner takes computer pictures of what's going on inside your body. The scan itself is painless. All you'll need to do is hold still for a few minutes at a time so the pictures come out clear. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.