When I first started in the imaging industry, one of the very first questions I had was what is the difference between a CT and MRI scan? After further exploration, I found this was a common question many people experience and often confuse. Both scans are used to capture detailed images inside the body. While both scans are low in risk and pain-free, there are differences that make each one a better option depending on the circumstances.
Easy Way to Differentiate CT and MRI
A CT uses radiation to capture clear images, similar to an X-ray, while an MRI uses a powerful magnetic field. When laying on the table, you can also tell the difference in the two machines. A CT is a large “Donut-Shaped” machine with a table in the middle whereas an MRI may be described as a “Tanning Bed” because you are placed inside a tunnel for the scan. Another big difference is the length of each scan, a CT is much faster than an MRI. Most likely, your doctor will recommend the appropriate scan based on your needs and conditions.
What is a CT Scan?
A CT is essentially an X-Ray machine that is hooked up to a computer, in fact, the name CT stands for “computerized tomography.” There is a very thin beam that takes a series of cross-sectional images of structures inside your body and converts them into pictures. These pictures are known as image slices and they come together to create a final 3-D image (more detailed than an X-Ray could ever be). Because a CT employs radiation, this is a very quick scan and takes no longer than 5 minutes.
A CT is commonly recommended for:
- Bone fractures, soft tissue, and organs
- Detecting tumors
- Monitoring cancer
- Evaluating lung and chest issues
- Finding internal bleeding
- Patients who struggle with claustrophobia or have metal implants
What is an MRI scan?
An MRI is a scan can produce an even more detailed snapshot of the body and often excels is showing certain diseases that a CT cannot detect. An MRI is a very loud machine because it uses radio waves and a very powerful magnet to generate the pictures of areas inside the body. In fact, MRI stands for “Magnetic Resonance Imaging.” MRI’s are typically a longer procedure that will take at least 30 minutes.
An MRI is commonly recommended for:
- Evaluating brain conditions
- Detailed imaging of organs and soft tissues, such as torn ligaments or herniated discs
- Showing difference between normal and abnormal tissue
- Abnormalities of the spinal cord and brain
Here is an animated Video showing 7 differences between a CT and MRI scan.