MR Arthrogram — shoulder

Glenohumeral joint, labrum, capsule and rotator cuff, with the same oblique planes as the routine shoulder study plus any additional position.

Typical, not policy

Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.

When to use it

Suspected labral tear in a young patient with instability, where conventional MRI is insufficiently sensitive.
Suspected superior labral anterior-posterior lesion.
Suspected partial articular-surface rotator cuff tear.
Assessment of the post-operative shoulder where the labrum has been repaired.
Persistent symptoms after a negative conventional MRI where surgery is being considered.

Technique

Image-guided injection under fluoroscopy, ultrasound or CT with sterile technique, then transfer to the scanner without delay.
Fat-suppressed T1 in oblique-coronal, oblique-sagittal and axial planes is the core arthrographic sequence set; a fluid-sensitive sequence is retained for marrow and extra-articular findings.
Abduction and external rotation positioning is commonly added to tension the anteroinferior labroligamentous complex.
Image quality declines as the injected contrast is absorbed and diluted, so the interval from injection to scanning should be kept short.

Where it goes wrong

Long delay between injection and scanning, allowing absorption and loss of joint distension.
Extravasation or an unrecognised intra-substance injection, producing inadequate distension and confusing extra-articular signal.
Contrast too concentrated, which causes T2 shortening and paradoxical signal loss rather than the expected bright fluid.
Bupivacaine used as the anaesthetic despite in vitro chondrotoxicity.
Omitting the abduction-external-rotation series when the anteroinferior labrum is the question.

Clinical questions that reach this study

Chronic shoulder pain — suspected rotator cuff tear or impingement Suspected labral tear — shoulder instability or femoroacetabular impingement

Contrast

Gadolinium, intra-articular

Intra-articular dilute gadolinium, conventionally around a 1:200 dilution in saline, often mixed with iodinated contrast for fluoroscopic confirmation and with a short-acting local anaesthetic. Typical injected volume for the glenohumeral joint is of the order of 10-15 mL.

The gadolinium here is injected into the joint, not into a vein, and the total gadolinium dose is a tiny fraction of an intravenous study.
Lidocaine or ropivacaine is preferred to bupivacaine, which is chondrotoxic in vitro.

Acquisition

Breathing: Not applicable.
Preparation: Consent, coagulation status and infection screening are needed as for any joint injection; anticoagulation should be declared at vetting. The injection and the MRI must be scheduled together — image quality falls once the contrast begins to be absorbed and diluted. Gadolinium here is intra-articular, not intravenous, and is used in a very small total dose; the renal considerations of an IV study do not transfer directly.

Safety checks this protocol carries

Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.

MR safety screening for implants and foreign bodies· radiographer at scan