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Types of image degradation in medical ultrasound.
| Type | Spatial coherence | Description |
|---|---|---|
| Phase aberration | Partially coherent18 | Speed of sound heterogeneities result in broadened acoustic beams and increased side lobe energy.3–10 |
| Reverberation | Incoherent11–13 | Random noise generated by system electronics.1,2,11–13 |
| Thermal noise | Incoherent13 | Loss of signal due to attenuation and transducer properties amplify electronic noise.14–17 |
