What’s the difference between an MRI and a CT scan? If your doctor recently ordered imaging for you, you might be wondering why one was chosen over the other. While MRIs and CT scans both produce images of the inside of your body, they create these images in different ways and are used for different reasons.
An MRI, also known as a magnetic resonance imaging scan, creates 3D images using magnets and radio waves. This scan is non-invasive, painless, and doesn’t use any radiation. MRIs are best for identifying issues with your soft tissue, spine, nerves, ligaments, or similar body parts. Conditions an MRI can diagnose include aneurysms & stroke, cancers, injuries to tendons, muscles, ligaments, bones & joints, spinal cord disease or damage, and urethra, uterine, bladder, vaginal or rectal issues.
A CT, or computerized tomography scan, creates 3D images using multiple X-rays taken at different spots around your body. Because these scans combine X-ray images, they are more detailed and accurate than a traditional X-ray. CT scans are best for identifying issues such as internal bleeding, blood clots, tumors, or infections. Conditions a CT scan can diagnose include abnormalities of the chest and lung, certain types of cancer, fractures, head injury, heart abnormalities or disease, tumors in the brain or lungs, and vascular diseases.
MRIs and CT scans can identify similar issues, but each has unique benefits that may lead your doctor to choose one or the other.
Because CT equipment is less expensive and the scans take less time to complete, it can be significantly cheaper to get a CT scan than an MRI. That shouldn’t scare you away from getting an MRI, though. Gateway Diagnostic Imaging strives to make MRIs as wallet-friendly as possible, ensuring you get the imaging you need for a price you can afford.
Folks with pacemakers, artificial hip replacements, and other metal implants can’t always get MRIs, as the metal will interfere with the magnets in the MRI machine. This depends on the type of metal and type of device. CT scans are a good alternative, as metal implants of any type won’t interfere with the scan.
MRIs are especially good at seeing organs and soft tissues, allowing doctors to check for subtle differences that a CT scan might not pick up.
While the amount of radiation a CT scan exposes you to is small, it can lead to a very slight increase in your risk for certain cancers. MRIs use magnets instead of radiation to create images, meaning you won’t have an increased risk of cancer with MRI imaging.
MRIs can be a bit noisy, requiring ear protection during the scan. By comparison, CT scans are much quieter. While CT scans can be better for claustrophobia, as your whole body doesn’t enter the machine, this is also possible with an MRI. Some MRI exams, such as those for an ankle or knee, may not require your entire body to enter the machine. Gateway Diagnostic Imaging also uses a 3T wide-bore MRI machine, which can help those with claustrophobia or anxiety feel more comfortable.
CT scans usually take between 10 and 30 minutes, depending on the area being scanned. MRIs generally take a little longer, with most completed in under an hour. Because they can be completed in less time, CT scans are often preferred in situations where quick results are needed, such as checking for internal bleeding after an accident.
MRIs and CT scans are both powerful, non-invasive tools that can help your doctor understand what’s going on inside your body. These forms of medical imaging can differ in cost, the way the images are created, and which conditions they’re best at diagnosing or exploring. Your doctor may choose one over the other for a number of reasons, such as how quickly they need results and which structures of the body they need to see.