MRI Versus CT Scan

Michelle Hopkins

Doctors often order diagnostic scans, such as a CT scan or MRI, when there is a concern that someone may be injured, have damaged tissue or be suffering from cancer. While both a CT scan and an MRI provide 3D images of the body, they do so in a different way and each type of scan has its own pros and cons. One of these scans is typically better than the other in any given situation.

How It Works

A CT, or computed tomography, scan works using a combination of x-ray technology and a computer to get a full 360-degree picture of your insides. As such, it does expose people to a limited amount of radiation. As these scans have gotten faster, the exposure to radiation has decreased. Someone taking a long plane trip will actually be exposed to more radiation than someone getting a typical CT scan. 

An MRI, or magnetic resonance imaging, scan uses a combination of radio waves and a magnet to produce its 360-degree images. This means it doesn't expose you to any radiation. It does take longer, however, and the machine can make noises that sometimes worry people getting the scan. An MRI typically takes about 30 minutes, while a CT scan usually takes between 5 and 20 minutes.

Best Uses

Each of these types of scans has its benefits, with CT scans being particularly good for examining bones and looking for this type of injury or for cancer cells, and MRI scans often being better for looking into injuries of the soft tissue in the body or comparing normal and abnormal tissues. In some cases, an MRI isn't possible, such as when a person has any metal implants, such as implanted medical devices like a pacemaker, or any other metal objects in the body. Even having tattoos may cause an MRI scan to be unsafe. In these cases, a CT scan can still be performed. In fact, this scan is often used to find foreign bodies made out of metal or tissue calcification. 


CT scans are typically less expensive than MRI scans. A CT scan without using contrast dye costs about $340, while one with dye costs about $840. Compare that to the cost of an MRI without dye at around $660 and one with dye at about $970. Using dye helps make any differences in the images clearer. While insurance will cover some of these costs, depending on the type of insurance the patient has, it may not cover all of them.

For more information, contact Omega Diagnostic Imaging PC or a similar company.