What Is the Difference Between a CT Scan and an MRI?

When you go to your doctor with symptoms of possible medical conditions that are not immediately obvious, there are a variety of diagnostic tools they can use to see what is going on inside the body. Computed tomography (CT) scans and magnetic resonance imaging (MRI) are two options that can help uncover injuries, illnesses, and chronic conditions that could be affecting your overall health and quality of life. At Intermountain Medical Imaging, we are a leading provider of CT scans, MRIs, and other services throughout the Boise area. The following explains some of the differences between a CT scan and an MRI and common reasons why doctors order each type of diagnostic test. 

The Difference Between a CT Scan and MRI

CT scans and MRIs are advanced diagnostic tools that allow our radiologists to obtain detailed images of the various parts of a patient’s anatomy and inner body structure. One of the main differences between these two diagnostic tests is that a CT scan relies on small doses of radiation to obtain these images while an MRI relies on radio waves and a strong magnet within the testing device.

Both procedures require the patient to lie on a flat table, which is then moved into the opening of the testing device. Both are painless, can be completed in a small matter of time, and provide detailed, accurate images with little preparation and no downtime for the patient.  

What Is a CT Scan?

A CT scan is a form of x-ray and uses a computer to obtain detailed images of body parts and organs. Sometimes referred to as a CAT scan, it is a safe and painless way to get a comprehensive look at what is going on within the patient’s body so that any underlying health conditions can be accurately diagnosed and managed.  

During a CT scan, a beam of radiation passes through the body, allowing the radiologists to obtain cross-sectional images. These take the form of thin ‘slices’ that are reconstructed by the computer, similar to the way that a slice of bread is only a part of the entire loaf. CT scans are the preferred technology for diagnosing the following types of conditions: 

  • Bone fractures;
  • Unexplained internal bleeding;
  • Tumors;
  • Cancer screening, which can involve identifying the source and monitoring patient progress. 

What Is an MRI?

Whereas CT scans rely on small doses of radiation, similar to an x-ray machine, an MRI relies on magnetic fields and radio waves. Once they pass through the body, these radio waves are transferred to another device, which translates them into 3-D images. 

MRIs are useful in diagnosing certain types of cancer other scans may have trouble detecting, such as those impacting the prostate, uterus, and liver. It is also often the preferred method in dealing with the following conditions:

  • Abdominal problems;
  • Injuries and diseases affecting the brain;
  • Breast lumps and pre-cancerous conditions;
  • Heart defects and diseases;
  • Spinal cord injuries and hereditary conditions;
  • Sports injuries;
  • Problems with veins and blood vessels;
  • Problems with vision and hearing function;
  • Issues involving joints, muscles, and other soft tissues. 

Which Is Better: a CT Scan or MRI?

Both CT scans and MRIs are important procedures offered at IMI for diagnosing and treating certain types of injuries, illnesses, and ongoing medical conditions. Depending on your symptoms, your doctor may decide to order one or even both types of testing. 

Some people prefer a CT scan as it is generally a quick test and the machine used tends to be quieter and less intimidating. A CT scan can often be conducted in 15 minutes or so. Depending on your symptoms, your doctor may require that you drink or have injected a contrast substance so that more detailed images can be obtained. This could extend testing time to up to a half-hour or longer. 

MRIs operate on similar time frames, but there are situations where it takes up to an hour to obtain the proper images. While some patients report feeling mildly claustrophobic after having an MRI in the past and at other facilities, IMI used the latest machines and technologies to help ensure your comfort.  

Contact Us Today for Help

At Intermountain Medical Imaging, we have been a trusted provider of CT scan and MRI testing for people throughout the Boise area for close to 20 years. To find out more about these procedures and to schedule a consultation, call or contact our offices online today.