Sonographic imaging of the distal phalanx.

Objective: To investigate the potential role of ultrasonography (US) with very high frequency transducers in assessing distal phalanx involvement in some rheumatic diseases. Methods: We performed sonographic evaluation with an Esaote AU-4 Idea (Esaote Biomedica, Genoa, Italy) equipped with a 13-MHz linear transducer. The images were obtained in asymptomatic healthy subjects and representative patients with psoriatic arthritis, osteoarthritis of the distal interphalangeal joint (Heberden's nodes), erosive osteoarthritis, gout, rheumatoid arthritis, systemic sclerosis, and posttraumatic synovial cyst. Results: US with very high frequency transducers allowed a careful identification of the following anatomic details: joint space, extensor and flexor tendons, bone margin, periarticular and peritendinous soft tissues, nail, and blood vessels, Several pathological changes were depicted in different rheumatic disorders. These included joint space widening, tendon sheath widening, dislocation of the joint surfaces, irregularity of the bone margin, and urate and calcium deposits within periarticular soft tissues. Conclusions: Very high frequency US is able to depict the anatomic substrate of distal phalanx involvement in several rheumatic diseases, adding useful information to clinical examination of the hand. Copyright (C) 2000 by W.B. Saunders Company.