Evaluation of post-exercise magnetic resonance images of the rotator cuff.
OBJECTIVE
To examine the effect of strenuous exercise on the magnetic resonance imaging (MRI) characteristics of the rotator cuff tendon. A second objective was to define an optimal time to image the rotator cuff and possibly eliminate exercise-induced false positives.


METHODS
Five male subjects from 24 to 38 years old with normal rotator cuffs by history, physical examination, and screening MRI underwent a rotator cuff exercise session on the Biodex System 2 (Biodex, Shirley, New York). The exercise sessions were followed by sequential MRI scans of the exercised shoulder. These were performed immediately and at 8 h and 24 h after exercise.


CONCLUSIONS
The rotator cuff tendon and subacromial-subdeltoid bursal signal remained unchanged from the pre-exercise through the 24-h post-exercise scans. The rotator cuff muscle signal was increased in five of five subjects on the immediate post-exercise fat-suppressed T2-weighted images. This signal returned to baseline by the 8-h scan. Positive findings of rotator cuff pathology on MRI after strenuous athletic activity should not be discounted as normal exercise-induced changes. Also, diagnostic MRI scanning may take place after a practice session without an increased risk of false positives.
Cahoy
P M
PM
Division of Orthopedic Surgery G5/358, University of Wisconsin Hospital and Clinics, Madison 53792-3228, USA.
Orwin
J F
JF
Tuite
M J
MJ
D000328:Adult; D015444:Exercise / Q000502:physiology*; D005189:False Positive Reactions; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D017006:Rotator Cuff / Q000033:anatomy & histology* / Q000502:physiology; D013997:Time Factors