Medically reviewed by Prof. Dr. Aamer Nadeem Chaudhary, M.B.B.S., D.M.R.D., F.C.P.S. (Diagnostic Radiology), Consultant, Al-Nasar Lab & Diagnostic Centre. Updated September 2026.
Quick answer: A shoulder MRI shows the rotator cuff tendons, the labrum, the biceps tendon, cartilage and the joint capsule, none of which appear on an X-ray. It is the test for a suspected rotator cuff tear and for shoulder pain that has not settled. It takes roughly 20 to 40 minutes, uses no radiation, and most studies need no injection.
Book a shoulder MRI: call 0300 0341944. MRI is performed at our main Johar Town campus.
What is the rotator cuff?
Four muscles wrap around the shoulder and their tendons blend into a cuff that holds the ball of the humerus into its shallow socket. The shoulder trades stability for range of movement, and the cuff is what makes that trade possible.
It is also what fails. The supraspinatus tendon, running across the top of the joint, is the most commonly torn structure in the entire shoulder. It passes through a narrow space beneath a bony arch, and repeated overhead activity, ageing and a reduced blood supply combine to wear it down.
That anatomy explains the classic symptom: pain on lifting the arm out to the side, and pain when lying on that shoulder at night.
What does a shoulder MRI show?
| Structure | Common finding | Typical symptom |
|---|---|---|
| Supraspinatus tendon | Tendinosis, partial tear, full thickness tear | Pain lifting the arm sideways, night pain |
| Other cuff tendons | Tears of subscapularis or infraspinatus | Weakness rotating the arm in or out |
| Muscle atrophy and fatty change | Long standing tear with muscle wasting | Important, as it predicts whether repair will succeed |
| Labrum | SLAP tear, Bankart lesion after dislocation | Clicking, catching, a sense of instability |
| Biceps tendon | Inflammation, subluxation, rupture | Pain at the front of the shoulder |
| Subacromial bursa | Bursitis, impingement | Painful arc of movement |
| Joint capsule | Thickening in adhesive capsulitis | Frozen shoulder, stiffness in all directions |
| Bone | Bruising, cysts, arthritis, acromion shape | Deep ache, restricted movement |
Rotator cuff tear or frozen shoulder?
These are frequently confused and they are treated completely differently, so the distinction matters.
A rotator cuff tear produces pain and weakness. The important feature is that if someone else lifts your arm for you, it usually goes up. The movement is available, it just hurts and the muscle cannot generate it.
Frozen shoulder, or adhesive capsulitis, produces stiffness. The capsule thickens and contracts, and the shoulder will not move even when someone else moves it for you. Loss of external rotation is the giveaway. It is strongly associated with diabetes, which makes it particularly common in Pakistan, and it can also follow a period of immobility after injury or surgery.
MRI can show both: the tear in one case, and the thickened capsule and inflamed tissue in the other. If you have diabetes and a painful stiff shoulder, mention it, because it substantially shifts the likely diagnosis. Checking HbA1c is often worthwhile in patients presenting with frozen shoulder.
When should you have a shoulder MRI?
- Shoulder pain lasting more than six weeks despite rest and physiotherapy
- Weakness lifting the arm, or inability to hold it out to the side
- Night pain that wakes you, particularly lying on that side
- After a dislocation, to assess the labrum and check for associated injury
- Clicking, catching or a feeling that the shoulder may give way
- A fall onto the shoulder or outstretched hand with continuing pain
- Before shoulder surgery, for planning
- When an X-ray is normal but symptoms persist
Why is an X-ray not enough?
An X-ray shows bone. It reveals arthritis, fractures, calcium deposits in the tendon and the shape of the acromion, and it is a sensible first test.
But the rotator cuff, the labrum and the capsule are soft tissue and are invisible on X-ray. A completely normal shoulder X-ray is entirely compatible with a full thickness rotator cuff tear. That is the gap MRI fills.
What is an MR arthrogram and when is it needed?
In an MR arthrogram, dilute contrast is injected directly into the shoulder joint under imaging guidance before the scan. The fluid distends the joint and pushes into any tear, outlining it clearly.
It is not needed for most rotator cuff questions. It is used mainly for labral tears, which are difficult to see on a standard MRI because the labrum sits tightly against the bone with nothing to separate the two. It is also used after previous shoulder surgery, when scar and fresh injury can look similar.
If your referral says arthrogram, allow extra time and expect a small injection into the joint before the scan itself.
What happens during the scan
You lie on your back with the arm being scanned at your side, usually palm upward. A coil is placed over the shoulder. Because the shoulder sits at the edge of the body, you are positioned slightly off centre so the shoulder is in the middle of the scanner.
This position can become uncomfortable over half an hour, so tell the technologist before you start if you have a particular restriction, and let them pad you properly. Being comfortable is not a luxury here, it is what allows you to stay still, and movement is the main cause of a repeated scan.
The scanner is loud and ear protection is provided. Each sequence lasts a few minutes and you can talk to the technologist between them.
Safety and preparation
- No fasting for a routine shoulder MRI. For an arthrogram, follow the specific instructions given at booking
- Tell the team about a pacemaker, defibrillator, cochlear implant, neurostimulator or aneurysm clip, and about any metal fragment in the eye
- Most orthopaedic implants are MRI safe, though metal near the shoulder can distort local images. Bring your implant card
- Wear clothing without metal, remove jewellery
- Bring previous X-rays, scans and your referral letter
- Mention any difficulty lying flat or keeping the arm in position
Shoulder MRI at Al-Nasar Lab
Al-Nasar Lab & Diagnostic Centre has served Lahore since 1996 and holds ISO 15189:2022 accreditation from the Pakistan National Accreditation Council. MRI at our Johar Town campus is reported by consultant radiologists, with images made available for your orthopaedic surgeon.
Related reading: knee MRI guide, is MRI safe and what to expect, and open MRI compared with closed MRI.
Contact us to book or find your nearest location.
Frequently Asked Questions
How long does a shoulder MRI take?
Usually 20 to 40 minutes. An MR arthrogram takes longer because contrast is injected into the joint beforehand.
Can an MRI detect a rotator cuff tear?
Yes. It shows whether the tear is partial or full thickness, how large it is, and whether the muscle has wasted, all of which guide treatment.
Do I need contrast for a shoulder MRI?
Usually not. Contrast injected into the joint is reserved mainly for suspected labral tears and for shoulders that have had previous surgery.
How do I know if I have frozen shoulder or a cuff tear?
A cuff tear causes weakness but the arm can usually be lifted passively. Frozen shoulder causes stiffness in all directions even when someone else moves the arm. MRI can distinguish them.
Will my head be inside the scanner?
Partly, because the shoulder is high on the body. Tell the team beforehand if enclosed spaces trouble you so they can plan accordingly.
This article is for general information and is not a substitute for medical advice. Please discuss your results with a qualified doctor.
