September 5, 2019

When Is Ultrasound Used vs. an MRI for Bone, Muscle and Joint Problems?

Understand how these imaging tests differ

Performing an ultrasound on a man

When aches, pains and other symptoms stem from a problem with the musculoskeletal system (meaning the bones, muscles, cartilage, tendons, ligaments and joints) your doctor may order an imaging test to help determine the underlying cause.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

There are several ways of looking inside the body, including X-rays, computed tomography (CT) scans and magnetic resonance imaging (MRI). Another one, high-resolution ultrasound, offers some advantages over the others for musculoskeletal problems.

“Some common reasons we do musculoskeletal ultrasound are to evaluate the rotator cuff in the shoulder, to look for Achilles tendon tears and to evaluate elbow tendon problems,” says diagnostic radiologist Michael C. Forney, MD. “But an ultrasound can be performed on most joints as long as the area evaluated is limited to just part of the joint.”

When is ultrasound used vs MRI?

“Sometimes patients wonder why an ultrasound is ordered instead of an MRI for musculoskeletal problems.” Dr. Forney says.

MRI and ultrasound look at the body in different ways.

MRI, which uses powerful magnets to produce 3-D anatomic images, is a high-contrast resolution modality that can determine changes in the tissue quality. With a muscle injury, for example, MRI images often show a bright signal indicating that there is more water in the muscle, which is a sign of injury.

Ultrasound uses high-frequency sound waves to look at organs and structures. It is a high-spatial resolution modality that provides greater, high-level detail of a structure, especially when it’s not too deep from the skin’s surface. “Ultrasound is like a flashlight that allows us to see high detail over a small area of tissue,” Dr. Forney says.

The advantages of ultrasound

“Ultrasound has many advantages as an imaging modality,” Dr. Forney says. “Ultrasound does not use any radiation and does require the patient to enter the bore or tube of a scanner, like with MRI or CT.”

Advertisement

Ultrasound can show pictures in real-time, like a movie, and therefore, can demonstrate abnormalities that are only seen with motion like impingent of the bursa in the shoulder, he explains.

“When structures are not very deep, or superficial, ultrasound can show images with higher resolution/detail than MRI,” Dr. Forney notes. The tendons in the fingers are often seen in greater detail with ultrasound compared with MRI, for example.

“Since ultrasound is like a flashlight, whereas MRI is like a flood light, there are times when ultrasound may not be able to make the diagnosis or may show findings that are indeterminate and need further testing,” he adds. “Nevertheless, ultrasound very often makes a diagnosis or provides useful information to your doctor about a musculoskeletal problem.”

Ultrasound can also be used to guide injections

Ultrasound isn’t just a diagnostic tool. When some type of injection treatment is needed, such as a corticosteroid shot into a joint, ultrasound can be used to visualize the structure to ensure that the needle is placed in the correct location.

Image-guided joint injections also are done with X-rays or CT scans. But with ultrasound, there’s no radiation and no need to inject a contrast dye.

What to expect during an ultrasound

With ultrasound, a specially trained technician or sonographer moves a handheld probe over the area to be studied. Once the sonographer feels that they have acquired diagnostic images, the radiologist will then interpret those images, typically within 24 hours.

Advertisement

“While we schedule most ultrasound patients for an hour, some examinations may take more or less time depending on what the sonographer finds,” Dr. Forney says.

When you should get an MRI

Ultrasound does have some limitations, and there are situations when MRI is needed instead. “Ultrasound does not show the structures inside joints,” Dr. Forney says. “We can only see the soft tissues outside, around the joint.”

To evaluate damage to cartilage, bone or other structures inside and around a joint, MRI is the better choice. MRI is also preferred for conditions that impact deep or large areas since ultrasound can evaluate only a small area at a time.

“If a patient needs a detailed look an entire joint, an MRI is a better test,” Dr. Forney says. Many times, however, your doctor may start with an ultrasound.

This article was adapted from Cleveland Clinic Arthritis Advisor.

Related Articles

patient lying on imaging table about to enter machine
December 14, 2023
CT Scan vs. MRI: How They Work and What They Show

CTs and MRIs use different technologies to show different things — neither is necessarily ’better’ than the other

person getting an ultrasound facial
October 15, 2023
How Ultrasound Facials Can Tighten Your Skin

This noninvasive procedure can help aging skin by boosting collagen production

doctor conducting an ultrasound on a knee joint
May 3, 2023
Two Sides of the Same Imaging Test: Ultrasound vs. Sonogram

One medical test, two different parts

Top view of person sitting in bathtub with cold water and lots of ice.
November 26, 2023
Brrr! What To Know About Cold Plunges

An ice bath can ease sore muscles and decrease inflammation after a workout

Person working on computer with hurting wrist.
November 23, 2023
11 Exercises and Stretches for Wrist Pain

Wrist flexor and extensor stretches are the best stretches for wrist pain

Person rubbing painful wrists and hands on lap.
November 16, 2023
16 Hand and Wrist Exercises To Help Ease Arthritis Pain

Simple exercises like tendon glides and finger lifts can have a big impact

Active elderly couple exiting tennis court
November 13, 2023
How Long Does a Hip or Knee Replacement Last?

They can last 10 to 15 years, but factors like age and activity level can impact their longevity

Trending Topics

White bowls full of pumpkin seeds, dark chocolate and various kinds of nuts
25 Magnesium-Rich Foods You Should Be Eating

A healthy diet can easily meet your body’s important demands for magnesium

Woman feeling for heart rate in neck on run outside, smartwatch and earbuds
Heart Rate Zones Explained

A super high heart rate means you’re burning more than fat

Spoonful of farro salad with tomato
What To Eat If You’ve Been Diagnosed With Prediabetes

Type 2 diabetes isn’t inevitable with these dietary changes

Ad