Glenohumeral arthrography
Glenohumeral (shoulder) arthrography is an imaging technique used to evaluate the glenohumeral joint to evaluate the joint components. A glenohumeral joint injection is usually performed under fluoroscopic guidance although ultrasound and CT can be also be used. An alternative to direct arthrography (where contrast is injected into the joint) is indirect arthrography.
Historically arthrograms were performed with fluoroscopy and plain radiographs only. Today all patients proceed to cross-sectional shoulder imaging after contrast injection. This is usually MRI but CT is sometimes performed if there are contraindications to MR or if there is high suspicion of an associated bony abnormality.
Indications
- shoulder instability
- glenoid labrum
- glenohumeral articular cartilage/ glenoid bone stock
- capsular tears - HAGL/ GAGL
- rotator cuff tears (prior repair)
Procedure
For direct arthrography, a glenohumeral joint injection is carried out commonly under fluoroscopy or CT guidance, although ultrasound guidance can also be used . The arthrographic contrast will depend on whether CT or MRI arthrography is being carried out.
CT injectate
Iodinated contrast with a concentration of no more than 240 mg of iodine per mL .
MR injectate
A very dilute (1/200 to 1/250) solution of gadolinium-containing MRI contrast agent is used in sterile saline (reaching a concentration of 0.0020–0.0025 mmol/mL) . Some centers may use a mixture of normal saline and local anesthetic as this has been shown to reduce artifact and periprocedural pain . A typical solution may be (but this will vary by institution) :
- 0.1 mL gadolinium MRI contrast agent
- 10 mL local anesthetic (e.g. 0.5% ropivacaine)
- 10 mL normal saline
The glenohumeral joint capacity is 8-15 mL, although a 12 mL intra-articular injection of the above 20 mL solution is typically adequate for joint distension .
If injected fluoroscopically or under CT guidance, then a small volume (1-3 mL) of dilute iodinated contrast can be injected first to confirm intra-articular position .
MR scanning should be performed within 90 minutes after intra-articular injection to ensure optimal image quality .
See also
