MRI of the shoulder: rotator cuff & what to expect

Shoulder pain, weakness or a suspected tear after an injury is often best assessed with an MRI, because it shows the tendons and cartilage that make the shoulder work.

What a shoulder MRI shows

MRI is the best test for the soft tissues of the shoulder.^[1] It can show:

• the rotator cuff — the group of tendons that move and stabilise the shoulder, to detect tears or inflammation;
• the labrum — the cartilage rim around the socket, which can tear (for example after a dislocation);
• other tendons, cartilage and signs of impingement;
• bone problems like a stress injury that an X-ray may miss.

An X-ray still shows the bones and alignment best, so both are sometimes used.^[2]

What to expect

A shoulder MRI uses no radiation.^[2] You lie on the table with your shoulder positioned in the scanner; it takes about 20–40 minutes, and you need to stay still. As with any MRI, it’s noisy (you’ll get ear protection), and the strong magnet means metal and implants must be screened — tell the team about any.^[3]

Many shoulder MRIs need no injection. For a suspected labral tear, a radiologist may do an MR arthrogram — injecting contrast into the joint first (using X-ray or ultrasound guidance) so the labrum shows up more clearly. See how an MRI works and MRI with contrast for more.

Frequently asked questions

What does a shoulder MRI show that an X-ray doesn’t?

The soft tissues — the rotator cuff tendons, the labrum and cartilage. An X-ray shows bones and alignment but not these, which is why MRI is used for tears and tendon problems.^[1]

What is an MR arthrogram?

It’s a shoulder MRI done after contrast is injected into the joint, which outlines the labrum and cartilage more clearly — used mainly when a labral tear is suspected.^[2]

Does a shoulder MRI use radiation?

No — it uses magnets and radio waves, not radiation. (If an MR arthrogram is done, the guidance for the injection may use a little X-ray or ultrasound.)^[2]