High-field magnetic resonance imaging findings in a young dog with septic arthritis of the shoulder joint

Koen M. Santifort

A 7-month-old, female Rough Collie with a history of diagnosis and treatment for steroid-responsive meningitis-arteritis was presented with a history of recurrent fever and lethargy and progressive lameness.

Magnetic resonance imaging revealed a large fluid intensity lesion (T2W hyperintense to muscle, T1W hypointense and in both sequences isointense to joint fluid) centred on the medial aspect of the right shoulder joint with outpouching into the surrounding muscle.

On post-contrast T1W images, there was extensive enhancement of the synovium and of the outpouching within the subscapularis muscle (centrally non-enhancing consistent with abscessation, haemorrhage or necrosis). Bacteriological culture and sensitivity testing on fluid of the shoulder joint and lesion revealed monoculture of multidrug-resistant Pseudomonas aeruginosa.

This case report illustrates the value of magnetic resonance imaging in the diagnosis of musculoskeletal pathology.