Ultrasonographic features of musculoskeletal soft tissue
| Condition | Characteristics on ultrasonography | Power Doppler |
|---|---|---|
| Normal tendon | Hyperechoic, compact internal fibrillar pattern Anisotropy may be present, mimicking tendinosis or tendon tearing | No signal |
| Tendinosis | Hypoechoic, focal or diffuse, abnormally thick-ened, loss of compact fibrillar structure and possibly regions of fiber disruption48,49 | With or without increased power Doppler signal |
| Tearing | Can differentiate partial- vs full-thickness tear | Complex fluid and blood can mimic intact tendon fibers; if tear is present, fluid does not move with joint movement as intact fibers would23 |
| Tenosynovitis or peritendinitis | Thickened tendon sheath or peritendon with increased fluid | With or without increased power Doppler signal |
| Normal ligament | Hyperechoic, compact morphology, less ordered fibrillar pattern than tendon | |
| Low-grade ligament injury | May be normal or thickened, hypoechoic | With or without increased power Doppler signal |
| Intermediate or high- grade ligament injury | Fiber disruption, surrounding hematoma or fluid | With or without increased power Doppler signal |
| Normal muscle | Mostly hypoechoic, interspersed hyperechoic lines and dots (perimysium and epimysium) | |
| Normal nerve | Less compact-appearing and more varied shape than tendon and ligament Semicompact bundle of hypoechoic nerve fascicles surrounded by hyperechoic tissue | |
| Neuritis (focal or diffuse) | Abnormal nerve enlargement, fascicular swelling, blurring of the interstitium, perineural thickening (in the chronic state), possible scarring in entrapment cases20 | With or without increased power Doppler signal |