Differential Diagnosis of Musculoskeletal Disorders
MRI Spectrum of Tendon Pathology
- Tendinosis
- fusiform thickening of tendon + ↑ SI on PDWI + T1WI
- ↑SI on T2WI ← severe intrasubstance degeneration
- Tenosynovitis
- fluid + synovial proliferation within tendon sheath
- Peritendinosis
- fluid in adjacent soft tissues
- Tendon rupture
- partial rupture
- focal areas of fiber discontinuity often outlined by fluid
- complete rupture
- complete fiber discontinuity (= disruption) of tendon
- fluid outlining retracted proximal + distal stumps
- partial rupture
- Tendon entrapment
- Tendon instability: subluxation / dislocation
Location: quadriceps, Achilles tendon, rotator cuff, biceps brachii
Cause:
- Traumatic
- Spontaneous
- = rupture during movement and activity that usually does not damage the musculotendinous unit
- Risk factors: hyperparathyroidism, chronic renal failure, gout, Reiter syndrome, obesity, leukemia, rheumatoid arthritis, diabetes mellitus, systemic lupus erythematosus, infection, metabolic diseases, psoriasis, steroid abuse / injections, Marfan syndrome, tumors, immobilization
Classification and findings on MR:
- partial tear
- increased signal within tendon on T1WI + T2WI with extension to surface of tendon
- focal / diffuse enlargement or atrophy
- partial disruption of tendon fibers
- focal intratendinous fluid
- tendon enhancement
- complete tear
- discontinuity + separation of torn ends of tendon
- interposed edema + hemorrhage