ARTHROGRAPHIC EFFECT INDUCED BY THERAPEUTIC ULTRASOUND IN MAGNETIC-RESONANCE-IMAGING OF THE WRIST - A PRELIMINARY INVESTIGATION

Objective: To evaluate the potential arthrographic effect of therapeut ic ultrasound applied before magnetic resonance imaging (MRI) of the w rist. Subjects and methods: MRI of the wrist was performed in 6 asympt omatic volunteers before and after ultrasound therapy of the carpus. F or each patient, ultrasound therapy was performed by a trained physiot herapist for 10 minutes, with doses titrated to the maximum tolerated without pain. The amount of fluid within the wrist joints before and a fter therapy was assessed subjectively by 2 reviewers, as well as obje ctively by digital analysis. Results: Subjective appraisal of the imag es indicated that after ultrasound therapy there was an increase in jo int fluid within the distal radioulnar joint in 4 volunteers, the midc arpal joint in 4 and the radiocarpal joint in 2. Computerized digital analysis of joint fluid confirmed an average volumetric increase in wr ist joint fluid of 52.8% in 3 of the volunteers. The discomfort of the therapy was graded as 1/10 by 5 of the subjects and 4/10 by a single subject. Conclusions: Therapeutic ultrasound may be a useful adjuvant tool in the noninvasive induction of joint fluid before MRI of the wri st.