There are a few differences between a magnetic resonance angiogram, or MRA, and a computed tomography, or CT, scan, such as what can be seen on the different scans, the procedures involved and their applications. MRAs are similar to a magnetic resonance imaging, or MRI, scan that use a magnetic field and radio waves to produce images of a body structure like a blood vessel's interior. A CT exam is a special X-ray exam that can take cross sectional views of the body that also uses a computer.
An MRA scan is an imaging option used when a diagnosis requires imaging of blood vessels and arteries that are causing blood flow problems in areas such as the brain, kidneys and legs, according to WebMD. It is a imaging better option because a CT scan can not provide this detailed information.
A computerized tomography is a procedure used to view bones and soft body tissue and is a better option to diagnose internal injuries caused in accidents, states the Mayo Clinic. A CT scan can be used to view the entire body and also may be done to diagnose a bone tumor, fractures and muscle disorders, relate the Mayo Clinic.
Another difference between these to tests are in the procedures involved for the them. In a MRA scan, the person is first injected with a contrast material and then is placed in a MRI machine for the test. For a CT scan, a person lies on a table and is placed in a scanning machine that rotates while it takes X-ray images.