MRI or CT Scan?

Imaging is one of the best ways for a physician to get a clear picture of what is going on inside your body. Imaging goes beyond physical examination, giving a physician a better understanding of your condition. You’ve probably heard of both MRI and CT scans, but how do you know which is right for you? Understanding the differences is a good place to start.

MRI – Magnetic Resonance Imaging

Unlike CT Scans, MRIs do not use radiation. Instead, MRI uses a magnetic field and radio frequencies to compile an image.

The duration of an MRI scan can vary greatly. It may take just a few minutes, or as long as a couple of hours.

MRI is ideal for imaging of tendons, ligaments, and soft tissues.

You’ve probably taken a picture of someone who was running or jumping, only to find that the photograph turns out blurry. They were moving too much for you to get a good image. The same rule applies to MRIs. A patient must remain very still during an MRI scan. Movement can blur the images captured during the scan, making those images unusable.

Since MRI uses a magnetic field, it’s not safe for patients with metal implants in their bodies to get this type of scan.

CT scan – Computed Tomography

Since CT scans use X-rays, there is radiation involved with this type of imaging. While the amount of radiation you will receive depends on the type of CT scan, it is generally a small amount. We are exposed to natural radiation during the course of our everyday lives. A low-dose CT scan emits less radiation than the average person is exposed to over the course of a year. The radiation seems insignificant when you compare it to the positives that can come from a CT scan.

CT scans are usually very quick. They can take less than five minutes and in some cases less than one minute.

A CT scan is best suited for detecting bone or muscle disorder, examining the lungs, and detecting cancer.

Just like with an MRI scan, patients must be still during a CT scan to get clear and usable images. Since the imaging speed is much faster than an MRI, CT imaging is affected less by slight movements, but it is still important that the patient remains as still as possible.

CT scans are safe for patients with metal implants.


While it’s good to know the differences between the two types of scans, your physician will know which option is best for you.