About an upper arm MRI scan
The upper arm runs from the shoulder to the elbow. It contains one long bone, the humerus, surrounded by muscles such as the biceps at the front and the triceps at the back, along with major nerves and blood vessels that supply the forearm and hand. An upper arm MRI uses a strong magnetic field and radio waves, not X-rays, to show the bone, muscles, tendons and nerves in detail.
An upper arm MRI may be used to look at:
- muscle and tendon injuries, such as tears of the biceps, triceps or pectoralis major (chest muscle) tendon, which can happen when lifting something heavy
- fractures, including stress fractures and fractures that do not show on X-ray
- lumps and swellings in the muscle or under the skin, to see their size and what they are likely to be
- unexplained bone pain, infection of the bone (osteomyelitis) and bone tumours
- problems with the nerves that run down the arm, such as the radial nerve
For problems in the joints themselves, a shoulder MRI or elbow MRI is usually the right scan. The biceps tendon most often tears at the shoulder or the elbow, so your referrer will say which area needs scanning. When you book, choose the left or right side.
What happens during the scan
You lie on your back on the scanner bed with your arm by your side, and a coil is placed over your upper arm. Pads may be used to help you keep your arm still. The scanner is loud, so you will wear ear plugs or headphones, and the radiographer can talk to you throughout. You need to keep your arm still while the pictures are taken. An injection of contrast dye (gadolinium) may be used to look at a lump or infection; where contrast is needed, it is charged separately.
What the scan can show
An upper arm MRI can help to look at:
- biceps, triceps and pectoralis tendon tears
- muscle strains, tears and bruising
- hidden and stress fractures of the humerus
- lumps in the muscle and soft tissue
- bone infection (osteomyelitis)
- bone tumours and cysts
- nerve problems, such as radial nerve injury
See a GP if you have a lump in your arm that is getting bigger, is larger than a golf ball, is painful, or comes back after being removed, or if you have bone pain that does not go away or is worse at night.
Preparing for your scan
No special preparation is needed, and you can eat and drink normally. Upload any previous X-ray, ultrasound or scan reports when you book, and remember to choose the correct side.
You can usually eat, drink and take your normal medicines unless the scanning centre tells you otherwise. Wear loose, comfortable clothing without metal zips or buttons, and leave jewellery at home. You will be asked to remove metal items such as hair clips, hearing aids, coins and keys, and you may be asked to change into a gown.
Before the scan you will complete a safety questionnaire. Tell the team if you have a pacemaker, any metal implant, surgical clips or other device, if you have kidney problems or allergies, or if you are, or might be, pregnant or breastfeeding. If you feel anxious in enclosed spaces, let us know when you book. Some centres can offer a relaxant, and if you take one you will need someone to take you home and must not drive for 24 hours.
Frequently asked questions
Can an MRI show a torn biceps?
Yes. MRI shows the biceps muscle and tendons and can show whether a tear is partial or complete, and where it is. Tears usually happen near the shoulder or the elbow, so tell us where your symptoms are when you book.
Should I have an upper arm, shoulder or elbow MRI?
An upper arm MRI looks at the bone and muscles between the joints. If your symptoms are mainly in the shoulder or elbow joint, a scan of that joint is usually better. Your referrer will say which is needed; if you are unsure, contact us before booking.
Do I need to choose a side?
Yes. Choose the left or right upper arm when you book. If both arms need scanning, contact us so the centre can plan the appointment.
Do I need a referral?
You can tell us if you have a referral from your GP, physiotherapist, dentist or consultant and upload it when you book. If you do not have one, select “no referral” when you book and the scanning centre will confirm the next steps with you.
Sources
- NHS – Arm pain
- NHS – Soft tissue sarcoma
- NHS – Bone cancer
- NHS – Osteomyelitis
- RadiologyInfo.org – Musculoskeletal MRI
- NHS – MRI scan
The information on this page has been gathered from various sources and is provided for general information only. It is not medical advice. TOP MRI is not liable for the accuracy or completeness of this information. Please speak to your doctor or the scanning centre about your own situation.