[KDI Healthcare Room: Health Information for October, 2019]

 

 

Hello! Today, I’d like to discuss the differences between CT scan and MRI, commonly used diagnostic medical imaging equipment in the hospital.

 

 

 

The difference between an MRI and CT scan

 

CT scans and MRIs are both used to capture images within your body. The biggest difference is that MRIs (magnetic resonance imaging) use radio waves and CT (computed tomography) scans use X-rays. While both are relatively low risk, there are differences that may make each one a better option depending on the circumstances.

 

 

 

What are CT scans?

 

A CT scan is a form of X-raying that involves a large X-ray machine. CT scans are sometimes called CAT scans.

 

A CT scan is typically used for:

 

- bone fractures

- tumors

- cancer monitoring

- finding internal bleeding

 

 

During a CT scan, you’ll be asked to lie down on a table. The table then moves through the CT scan to take cross-sectional pictures inside your body.

 

 

 

What are MRIs?

 

Using radio waves and magnets, MRIs are used to view objects inside your body.

 

They’re frequently used to diagnose issues with your:

 

- joints

- brain

- wrists

- ankles

- breasts

- heart

- blood vessels

 

A constant magnetic field and radio frequencies bounce off of the fat and water molecules in your body. Radio waves are transmitted to a receiver in the machine which is translated into an image of the body that can be used to diagnose issues.

 

An MRI is a loud machine. Typically, you’ll be offered earplugs or headphones to make the noise more bearable. You’ll also be asked to lie still while the MRI is taking place.

 

 

 

What are some risks?

 

Both CT scans and MRIs pose some risks when used. The risks are based on the type of imaging as well as how the imaging is performed.

 

CT scan risks include:

 

- harm to unborn babies

- a very small dose of radiation

 

MRI risks include:

 

- possible reactions to metals due to magnets

- loud noises from the machine causing hearing issues

 

You should consult a doctor prior to an MRI if you have implants including:

 

- artificial joints

- eye implants

- an IUD

- a pacemaker

 

 

 

Choosing between an MRI and CT scan 

 

Most likely, your doctor will give you a recommendation based on your symptoms whether you should get an MRI or CT scan.

 

If you need a more detailed image of your soft tissue, ligaments, or organs, your doctor will commonly suggest an MRI.

 

If you need a general image of an area like your internal organs, or due to a fracture or head trauma, a CT scan will commonly be recommended.

 

CT scans and MRI scans are relatively low risk and both offer important information to help your doctor properly diagnose specific conditions. Most likely, your doctor will tell you which one they recommend. Be sure to ask questions and discuss any concerns with your doctor, so you can be comfortable with the choice they recommend.

 

 

※ References 

 

- University of Virginia Health System: Radiology and Medical Imaging, https://blog.radiology.virginia.edu

- Healthline, https://www.healthline.com (Infographic)