PHYS3 Artifacts Word Scramble
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| Artifact: | Group(s) | Correct by: |
| Axial resolution | Propagation | ↑ frequency |
| Lateral resolution | Propagation | ↑ frequency |
| Section thickness | Propagation | ↓ gain and/or TGC OR ↑ z axis (3rd dimension) focus |
| Acoustic Speckle | Propagation | ↓ gain or ↓ frequency |
| Reverberation | Propagation | multiple matching layers |
| Refraction | Propagation | change angulation of transducer |
| Multipath | Propagation | change angulation of transducer |
| Mirror image | Propagation / Doppler | change angulation of transducer |
| Side lobe | Propagation | inherent within the transducer ↓ gain |
| Grating lobe | Propagation | inherent within the transducer ↓ gain |
| Comet tail | Propagation | inherent within the tissue |
| Ring-down | Propagation | inherent within the tissue |
| Speed error | Propagation | inherent within the tissue |
| Range ambiguity | Propagation / Doppler | PROPAGATION: ↓ PRF (↑PRP) by ↑ imaging depth DOPPLER: Need to ↑ PRF to decrease aliasing, but this can cause range ambiguity artifact |
| Main bang | Propagation | • Multiple matching layers • Electronic focusing • ↑ Frequency • ↓ Near gain • Stand-off pad |
| Shadowing | Attenuation / Doppler | inherent within the tissue |
| Enhancement | Attenuation | inherent within the tissue |
| Refraction (edge) shadowing | Attenuation | inherent within the tissue • Change angulation of transducer so it is perpendicular to anatomy |
| Focal enhancement | Attenuation | inherent within the transducer • ↓ gain in mid field (or wherever the focal zone is – use TGC to adjust) |
| Aliasing | Doppler | • Adjust baseline • Adjust scale • ↑ PRF • ↑ Doppler angle (only if bad to begin with – must remain between 45° and 60°) • ↓ transducer frequency • ↓ sample volume depth • Use CW Doppler |
| Speckle (noise) | Doppler | ↓ gain |
| Doppler angle effects | Doppler | use “angle correct” control or change Doppler angle |
| Clutter | Doppler | ↑ wall filter |
Created by:
lefut
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