Arthrography: What an MR or CT Arthrogram Actually Is

Plain-language definition

Arthrography is an imaging exam in which a small amount of contrast is injected directly into a joint and then imaged — most often with MRI, sometimes with CT. The contrast fills the joint space, distends the capsule slightly, and outlines structures like the labrum, cartilage, and intra-articular ligaments. Subtle tears that would be invisible on a routine MRI suddenly stand out, because the contrast leaks through any tear and traces its exact shape.

When the follow-on imaging is MRI, the study is called an MR arthrogram. When it's CT, it's a CT arthrogram. The injected contrast is typically a dilute mixture of gadolinium (for MR) or iodinated contrast (for CT) along with saline and sometimes a small amount of local anesthetic.

Why it matters

Arthrography is the gold-standard exam for diagnosing subtle joint pathology that a standard MRI may miss or call indeterminate. It's most commonly used for:

• Shoulder. Labral tears (SLAP lesions, Bankart lesions), recurrent instability, post-operative repairs.
• Hip. Labral tears, femoroacetabular impingement (FAI), pre-arthroplasty evaluation.
• Wrist. Triangular fibrocartilage complex (TFCC) tears, intra-carpal ligament tears.
• Elbow and ankle. Less common but used for selected ligament or osteochondral injuries.

The exam is typically ordered after a routine MRI is inconclusive, or up front when the clinical suspicion for a subtle tear is high — particularly in throwers, climbers, and patients with recurrent instability.

How an arthrogram shows up in a Precise Imaging context

A Precise arthrogram has two distinct phases:

Phase 1 — joint injection (about 20 minutes)

1. You're positioned on a fluoroscopy or ultrasound table.
2. Skin around the joint is cleaned and numbed with a local anesthetic.
3. A thin needle is advanced into the joint under image guidance (fluoroscopy or ultrasound). The radiologist confirms intra-articular position with a tiny test dose of contrast.
4. The contrast mixture (typically 10–20 mL depending on the joint) is injected.
5. The needle is removed and the joint may feel briefly "full" — that sensation goes away in a few hours.

Phase 2 — diagnostic MRI or CT (30–45 minutes)

You move to the MRI or CT suite for the diagnostic scan. The contrast is most informative within the first 30–60 minutes of injection, so timing matters — we coordinate it tightly between the two suites.

After the exam, you can drive home (no sedation is given) but we recommend taking it easy on the joint for the rest of the day.

Disclaimer

This explainer is general patient education and not medical advice. Whether arthrography is right for you and which joint(s) to image are decisions made by your ordering provider in consultation with the supervising radiologist.

Frequently asked questions

Does the injection hurt?

Most patients feel a brief sting from the local anesthetic and pressure during the contrast injection. Pain is usually mild and brief. We use thin needles and the smallest contrast volume needed for diagnostic quality.

Will I need a driver?

Most patients drive themselves home. We do not give sedation for an arthrogram. The joint may feel mildly sore for 1–2 days; over-the-counter pain relief is usually sufficient.

What can I do after?

Rest the joint for the remainder of the day. Avoid heavy lifting, high-impact activity, or sports for 24 hours. Normal activity can resume the next day.

Are there risks?

Serious complications are rare. The most common issues are temporary post-procedural soreness and a small risk of infection (well under 1 in 1,000 with sterile technique). Tell us if you develop fever, redness, warmth, or increasing pain.

Why not just do a regular MRI?

For some questions a routine MRI is enough. For subtle labral or intra-articular tears, the joint distension and contrast outline that arthrography provides materially improve diagnostic accuracy.