CT Scan vs. MRI: What’s the Difference? And Why Would my Doctor Choose One Over the Other?

If you’re dealing with an injury or condition where there’s bleeding, a scar, bruising, or rashes, there’s a straightforward process to start diagnosing from. However, those conditions may not show the whole issue, and many pains and other illnesses may not be visible. Making decisions on what it is and how to treat it becomes more difficult.

Medical imaging has been a vital part of diagnosis and treatment for many years, going back as far as the X-ray. However, not all imaging methods are equal; some are better suited for different medical problems. Computed tomography (CT) scans and magnetic resonance imaging (MRI) are two ways to look inside the body and find out what’s going on, but what are the differences, and when should you use them?

Let’s find out by reviewing how each device works and what they’re best at examining. If you live in the Winter Park, Orlando, or Lake Mary, Florida, area and need medical imaging, Dr. George Stanley and his experienced staff at University Diagnostic Institute can help.

How MRIs work

This tube-shaped device creates a magnetic field and can fit a person on a platform that gathers detailed imaging for systems throughout the body. When the platform moves inside the magnet, the device emits radio waves and hydrogen atoms that create cross-sectional imagery, which is collected and compiled to generate 2D or 3D pictures for diagnosis viewing. 

There are variations of the technology used to examine blood flow through the arteries (magnetic resonance angiography, or MRA) and functional magnetic resonance imaging (fMRI) to look at specific locations and functions of the brain.

How CT scans work

This imaging device examines the internal workings of your body with a platform that moves through a cylindrical device and uses detailed X-rays to gather the information by creating cross-sectional images assembled in a computer for analysis. 

This method requires using a contrast to observe as it moves through the body during a scan, which can be given orally, as an injection, or through an enema.

Reasons to use one as opposed to the other

The choice between the two imaging methods depends on many factors related to:

Risks

Each method carries specific risks based on how they work. CT scans use radiation, and while the levels are low, they still pose possible threats to unborn babies, have varying doses of radiation depending on the kind of scan, and may cause adverse reactions to the dyes used in the contrast. 

MRIs have different issues that may pose problems, including loud noises from the machine causing hearing issues, long MRIs causing increases in heat, and claustrophobia.

Details

CT scans are the go-to for information on bone fractures, tumors, internal bleeding, and cancer monitoring. However, MRIs offer greater detail of the tissues and organs, making them ideal for herniated discs, torn ligaments, and other issues in soft tissue.

Implants

Implants are a risk unique to MRIs. Because MRIs use a magnet, any metals can create issues, so they get removed before you enter the device. However, implants can pose a different threat, so artificial joints, pacemakers, intrauterine devices, and others can make getting an image very difficult.

Each method has value, but you can take time to decide on one over the other. If you need diagnostic care and aren’t sure which method to choose, make an appointment with Dr. Stanley and his team at University Diagnostic Institute today.