Arthrography is the injection of contrast into a joint — most commonly the shoulder, hip, wrist, ankle, knee, or elbow — to improve visualisation of internal joint structures on imaging. The fluoroscopy part is the injection itself; the imaging that follows is almost always an MRI (MR arthrogram) or occasionally a CT (CT arthrogram).
This guide explains what happens during the injection and why your doctor may have requested this rather than a plain MRI.
Common Indications for Arthrography
Your doctor may request arthrography to investigate:
- Shoulder — labral tears (SLAP lesion, Bankart lesion), rotator cuff partial tears, recurrent dislocation.
- Hip — labral tears, femoroacetabular impingement, post-operative joint evaluation.
- Wrist — triangular fibrocartilage complex (TFCC) tear, scapholunate ligament tear.
- Ankle — ligament tears, osteochondral defects.
- Knee — meniscal repair follow-up, occasional cartilage assessment.
- Elbow — ulnar collateral ligament evaluation in throwing athletes.
The arthrogram is typically a follow-up test after a plain MRI has been done and either was inconclusive or specifically requires the contrast distension to answer the clinical question.
What exactly does arthrography show?
Injecting contrast into the joint distends it gently and outlines internal structures that are otherwise tightly apposed. This makes it possible to see:
- Tiny tears in the labrum (the cartilage ring around the shoulder and hip sockets).
- Subtle ligament tears within the joint.
- Cartilage defects that touch each other in the resting joint.
- Loose bodies within the joint.
- Post-operative changes after surgical repair.
For an MR arthrogram, dilute gadolinium contrast is injected — gadolinium shows up bright on MRI. For a CT arthrogram, iodine-based contrast is used.
What happens during the procedure?
- You change into a gown and lie on the X-ray table.
- The radiologist cleans the skin over the joint with an antiseptic solution.
- A local anaesthetic is injected into the skin and deeper tissues — there is a brief sting, then numbness.
- A thin needle is advanced into the joint under fluoroscopy guidance. The radiologist confirms the needle position by first injecting a very small amount of iodine contrast (or saline) and watching it flow inside the joint.
- The contrast for the upcoming MRI or CT is then injected, sometimes mixed with a small dose of local anaesthetic so the joint is more comfortable afterward.
- The needle is removed and a small dressing is applied.
The injection itself takes about 10 to 20 minutes.
You then move to the MRI or CT scanner — usually within 30 minutes of the injection, before the contrast can disperse. The scan itself adds another 30 to 60 minutes.
Do I need to prepare?
- No fasting is required.
- Wear comfortable clothing — you will change into a gown.
- Tell the team if you have ever had a reaction to gadolinium or iodine contrast.
- Tell the team about any blood-thinning medications you take. Most can be continued, but some patients may be asked to pause warfarin or higher-dose blood thinners briefly.
- Tell the team if there is any chance of pregnancy.
Will the procedure be painful?
The injection itself is uncomfortable rather than painful, thanks to the local anaesthetic. Most patients report a brief sting from the anaesthetic, then a feeling of pressure or fullness in the joint as it is distended.
After the test, the joint may feel fuller and slightly more stiff than usual for 6 to 24 hours as the body absorbs the injected contrast. Many patients also notice the joint feels temporarily better because of the small amount of local anaesthetic mixed with the contrast. Both effects pass.
How long do the results take?
The radiologist reads the MRI or CT after the scan is complete. Reports typically reach your doctor within 24 to 72 hours.
Are there risks?
Generally low-risk, with a few worth knowing
- Mild pain or swelling in the joint for 24 to 48 hours — common and self-limiting. Paracetamol or ibuprofen usually helps.
- Infection of the joint — extremely rare with sterile technique (around 1 in 10,000). Watch for severe pain, redness, fever, or chills in the days after the procedure.
- Allergic reaction to contrast — uncommon, particularly because the dose is small.
- Bleeding into the joint — uncommon, more likely in patients on blood thinners.
- Radiation exposure — small dose from the fluoroscopy guidance.
Call the imaging centre or your doctor urgently if you develop a hot, swollen, very painful joint, redness, or fever in the 1 to 7 days after the procedure.
What about activity restrictions afterward?
For 24 to 48 hours after the procedure, avoid heavy use of the injected joint — no heavy lifting after a shoulder arthrogram, no running after a hip arthrogram. Normal walking, light desk work, and gentle activities of daily living are fine. The joint usually feels back to baseline within 1 to 2 days.
Why not just do an MRI without contrast?
A plain MRI is the right first test for most joint problems and detects most significant abnormalities. Arthrography is reserved for cases where:
- The clinical suspicion is high but the plain MRI was equivocal.
- The specific lesion suspected is known to be more visible with contrast distension (such as a SLAP tear of the shoulder or a hip labral tear).
- The joint has been operated on before, and post-surgical changes obscure the plain MRI.
Your radiologist or referring surgeon will guide which type of study is right for your situation.
Conclusion
Arthrography is a targeted, minimally invasive procedure that significantly improves the diagnostic accuracy of MRI or CT for specific joint problems — particularly subtle labral, ligament, and cartilage injuries. The injection takes 10 to 20 minutes, is performed under local anaesthetic, and is generally well tolerated. For the right clinical question, it is one of the most diagnostically powerful imaging strategies available.