MR Arthrography - Shoulder

Direct MR arthrography distends the glenohumeral joint with dilute gadolinium, separating intra-articular structures and allowing contrast to outline tears of the labrum, capsule and articular surface of the rotator cuff. It substantially improves sensitivity for labral and partial-thickness cuff pathology compared with conventional MRI, and is the reference test in the young unstable or post-operative shoulder.

Indications

Suspected glenoid labral tears including SLAP and Bankart lesions
Shoulder instability and evaluation of the capsulolabral complex
Partial-thickness (particularly articular-surface) and small rotator cuff tears
Assessment of the post-operative cuff and labrum where fluid signal is equivocal
Suspected biceps anchor and superior labral pathology
Evaluation of adhesive capsulitis and capsular volume

Contraindications & Cautions

Non-conditional pacemakers, ICDs, neurostimulators and ferromagnetic implants
Active infection or cellulitis over the injection site
Known allergy to gadolinium or iodinated contrast used for needle localisation
Bleeding diathesis or anticoagulation increasing haemarthrosis risk (relative)
Pregnancy: relative caution; the intra-articular gadolinium dose is small but justify the study

Patient Preparation

Explain the two-stage procedure: image-guided injection followed by MRI
Obtain informed consent for the arthrogram and screen for contrast allergy
Aseptic technique; fluoroscopic or ultrasound-guided anterior (rotator interval) or posterior approach
Inject 12-15 mL of dilute gadolinium (approximately 2 mmol/L, ~1:200 in saline) to distend the joint
Move the patient promptly to the scanner and image within ~30-45 minutes before contrast resorption

Technique & Parameters

Fat-saturated T1-weighted sequences in axial, oblique coronal and oblique sagittal planes
At least one fluid-sensitive sequence (T2 or PD fat-sat) to detect extra-articular fluid and marrow oedema
Abduction-external rotation (ABER) view to open the antero-inferior labrum and articular cuff
Small field-of-view with a dedicated shoulder coil for high spatial resolution
Optional traction or specific positioning to improve labral separation
1.5T or 3T; 3T offers superior resolution for subtle labral and cuff tears

Systematic Review

Confirm adequate joint distension by intra-articular contrast
Trace the labrum clock-face, assessing each quadrant for contrast undercutting a tear
Evaluate the superior labrum and biceps anchor for SLAP lesions
Assess the articular surface of the supraspinatus/infraspinatus for contrast tracking into a tear
Inspect the capsule, inferior glenohumeral ligament and HAGL, and the rotator interval
Review the humeral head and glenoid for Hill-Sachs and bony Bankart lesions on the fluid-sensitive series

Key Findings & Significance

Bankart lesion: antero-inferior labral tear with contrast undercutting, +/- bony fragment (bony Bankart)
SLAP lesion: contrast extending into the superior labrum at the biceps anchor, best on coronal images
Perthes and ALPSA variants: labroligamentous stripping with periosteal sleeve or medially displaced labrum
Articular-surface partial-thickness rotator cuff tear: contrast tracking into the cuff undersurface without full extension
HAGL lesion: contrast extravasation through a disrupted inferior glenohumeral ligament at its humeral attachment
Adhesive capsulitis: reduced joint volume, thickening of the capsule and rotator interval

Differential Considerations

Superior labral high signal: SLAP tear versus normal sublabral recess or foramen and Buford complex variant
Antero-inferior labral abnormality: Bankart, Perthes, ALPSA, GLAD lesions
Cuff undersurface irregularity: partial tear versus tendinosis or normal footprint
Paralabral cyst with signal: labral tear versus ganglion
Capsular thickening: adhesive capsulitis versus normal variation

Pearls & Pitfalls

Know the normal variants (sublabral recess, sublabral foramen, Buford complex) to avoid overcalling a SLAP tear
The ABER position tensions the antero-inferior band and improves detection of non-displaced Bankart and articular cuff tears
Contrast tracking into a structure is the hallmark of a communicating tear; intrasubstance signal alone may be degeneration
A Buford complex (absent antero-superior labrum with a cord-like middle glenohumeral ligament) must not be mistaken for a tear
Always include a fluid-sensitive sequence to detect marrow oedema, extra-articular fluid and paralabral cysts

Structured Report

State the injection approach, contrast volume and field strength
Confirm joint distension and describe labral integrity by location/clock-face
Report rotator cuff articular and bursal surfaces and any tear extent
Describe capsule, glenohumeral ligaments, HAGL and biceps anchor
Note bony lesions (Hill-Sachs, bony Bankart) and provide a surgical-oriented impression

References

ACR-SSR Practice Parameter for the Performance and Interpretation of MR Arthrography
Steinbach LS, et al. Radiographics: MR arthrography of the shoulder
Waldt S, et al. Anterior shoulder instability: MR arthrographic classification. Radiology
Chang EY, et al. MR arthrography of the shoulder: technique and pathology

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

MR Arthrography - Shoulder

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References