Skip to main content

How to Understand a CT Scan

A CT, or CAT, scan combines a series of X-ray images to produce cross-sectional views of the bones and soft tissues in your body.


  • TIP: Some scan protocols require that a special dye be injected into your body before the scan begins. The most common dye is iodine.
  • Step 1: Know that CT scans create low levels of ionizing radiation. This radiation can cause cancer and other defects. But most doctors believe that CT scans can provide enough valuable information to outweigh potential risks. Now take comfort in knowing how CT scans work.
  • FACT: Sir Godfrey N. Hounsfield shared the 1979 Nobel Prize in medicine for his role in developing computerized axial tomography.
  • Step 2: Learn that the CT scan is performed in a large donut-shaped x-ray machine. During the scan the patient lies flat on a narrow table that slides into the scanner. A complete scan typically takes only a few minutes.
  • Step 3: Recognize that a CT scan combines multiple X-ray images to generate cross-sectional views of your body. A computer combines the X-ray information and uses it to create 3-D images.
  • TIP: CT stands for computerized axial tomography.
  • Step 4: Understand that a CT scan can define normal and abnormal structures in your body. A scan is considered normal if the organs and structures examined appear normal.
  • Step 5: Know that CT scans are used to perform biopsies, identify masses and tumors, and study blood vessels. The scans can obtain detailed pictures of your body, including your brain, chest, spine, and abdomen.

Popular Categories