What is the MRI appearance of tendon degeneration, tendon tear, and tenosynovitis?
Degeneration of a tendon is seen as increased signal intensity within the normally low signal intensity tendon and either enlargement or attenuation of the tendon in cross-section. A full-thickness tear is seen as a discontinuity of the tendon with variable degree of separation of the two ends. Partial-thickness tears are seen as a focal attenuation of the tendon, although the distinction between partial-thickness tear and chronic attenuation associated with degeneration can be difficult if not impossible to make with confidence. Tenosynovitis is seen as distention of the surrounding tendon sheath (tenosynovium) by fluid that has low signal intensity on T1-weighted images and high signal intensity on T2-weighted images.