CT scan vs. MRI scan

What is the difference between CT scan and MRI scan?

CT is the shortened form of Computed Tomography. Images are taken by means of X-Rays, which are high energy rays that you cannot see with the naked eye. Tissues can obstruct the X-rays, but bones resist X-rays even more so. On an X-ray film, bones show up as being white. The image is also two-dimensional because it gives an axial view of the tissue. In recent years, three-dimensional CT scams have become available.

The computer program used in a CT scan computes the image of the tissue and reconstructs the image. However, there are a lot more X-rays used in a CT scan and there can be side effects to this procedure. Cancer can result from repeated scans.

MRI is the shortened form of Magnetic Resonance Image. This procedure is not as harmful as a CT scan because it uses magnetic rays instead of X-rays. The MRI machine is very similar to the CT scanner, but it gives a better image of the soft tissue. For example, it is better for brain and spinal cord images. It is also safe to use MRI during pregnancy because of the lack of radiation, which does exist in CT scanning.  Three dimensional MRI pictures are perfect for diagnosing diseases of the blood vessels.

It takes more time to take an MRI than it does for a CT scan because the patient has to spend a longer period of time inside the tube. Anyone who is claustrophobic may have problems with this procedure. A patient has to be fully aware during an MRI, but it is possible to do a CT scan on an unconscious patient.

You do not need to do any advance preparation for a CT scan, but you do with an MRI. If you have any metal tooth clips, for example, you must remove them before you can have one of these procedures. Therefore anyone who has had surgery and has anything metal inside the body will not be able to have an MRI procedure. This is because the magnetic field will pull out the metal.


  1. Both CT scan and MRI are imaging techniques used to diagnose diseases and conditions in the body.
  2. CT scans used X-Ray, which can be harmful. Pregnant women cannot have a CT scan because of the radiation.
  3. An MRI does not use radiation and is therefore safer to use. Pregnant women can have this procedure, but anyone that has metal in the body from surgeries cannot have an MRI.
  4. No preparation is needed for a CT scan, but it is needed for an MRI.
  5. MRI provides a much better 3-dimensional picture.
  6. MRI is better for soft tissue images.