The Differences Between CT Scans and MRIs

Posted on July 16, 2018

Computed tomography (CT) and magnetic resonance imaging (MRI) scans are both important diagnostic tools used at diagnostic imaging centers in Suffolk County, NY. Your medical team can use CT and MRI scans to generate pictures of the inside of your body to use in the diagnosis and monitoring of diseases such as cancer, congenital heart disease, cirrhosis, Crohn’s disease, and more.

While in some instances either diagnostic imaging technique can be used, your doctor may recommend one over the other depending on your specific circumstances. An MRI may be preferred to diagnose issues in soft tissues and organs, joints, tendons, and ligaments, while a CT scan is more helpful in diagnosing serious head, chest, abdomen, spinal, and pelvic injuries, such as fractures.

Though both CTs and MRIs are important diagnostic imaging technologies, there are some distinctions between the two. Read on to learn how they differ and how they’re used at Peconic Bay Medical Center for advanced diagnostic imaging in Suffolk County, NY.

Doctor Reviews Scan

Use of Radiation

The main difference between the two types of diagnostic imaging is the use of radiation in CT scans. CT scans — which were previously known and sometimes are still referred to as CAT scans — is a process that involves X-rays. In a CT scan, multiple X-rays of the part of the body being examined are taken at different angles, and a computer creates 3-D images from them.

Because X-ray beams are utilized in this process, the patient undergoing the scan is exposed to ionizing radiation. Too much exposure to radiation can lead to the development of cancer. However, a CT scan uses a fairly small dose of ionizing radiation, and the risk of developing cancer from exposure is small. If you’re concerned about exposure to radiation, consult with your doctor before scheduling a CT scan.

CT machine settings can be adjusted to perform scans on children, who are more sensitive to ionizing radiation. Consult with your child’s doctor before a scan. CT scans aren’t recommended for use on pregnant women to perform imaging on the abdomen and pelvis. Let your doctor know if you are pregnant and they can discuss alternative imaging options.

MRI Machine

Time to Complete

Though the time taken to perform either a CT scan or an MRI can vary depending on a variety of factors including the part of the body being examined, MRIs generally take longer to complete than CT scans. MRIs provide images that are more detailed, so it takes longer to collect them. Also, CT scans are generally used in situations where a diagnosis is needed quickly, and MRIs are preferred for nonemergency situations where more time can be taken for examination.

Requiring more time to complete also means that MRIs are more expensive, but there can be an impact on more than a patient’s wallet. For patients who are claustrophobic, spending the time in an MRI machine that is required to complete the scan can be daunting. If you are due to have an MRI and suffer from claustrophobia, your doctor may come up with a different imaging test or provide you with a sedative for you to take ahead of the procedure.

If your doctor has recommended you undergo a CT or MRI scan, contact the experts at Peconic Bay Medical Center for diagnostic imaging in Suffolk County, NY. Learn more about the services they offer at