Cardiac US Artifacts Flashcards
Reflections return from a narrow transmit beam
Assumption
Beam width
Artifact
Reflections return from objects located on beam’s central axis
Assumption
Side lobe; grating lobe; refraction; beam width
Artifact
Sound waves travel in straight line
Assumption
Refraction
Artifact
Sound travels at a constant speed of sound in tissue, 1,540 m/s
Assumption
Propagation speed; comet tail; refraction
Artifact
Reflections from an object are related directly to the reflective strength of that objection
Assumption
Shadowing; enhancement
Artifact
Sound takes a single round trip to a reflector and back
Assumption
Reverberation, near-field clutter; mirror image; range ambiguity; comet tail
Artifact
Reverberation
Mech: repetitive reflectors
Farther away from true object
Mechanical valves, pacemakers
Near-field clutter
Mech: strong reflector near-field
Farther away from true object
LV apex pseudo mass
Refraction
Mech: Lens effect with change of velocity
To the side of true object
double image aortic valve, LV
Range ambiguity
Mech: out of view reflector
Closer than true object
Pseudo mass LV
Mirror image
Mech: image on two sides of reflector
Farther away from true object
Mitral valve below diaphragm
Side lobe
Mech: reflector off central beam
To the side of true object
LV clutter, LAA ridge widening
Grating lobe
Mech: reflector off centeral beam
To the side of true object
Similar to side lobes seen more with linear array transducers
Propagation speed
Mech: speed of sound > or < 1,540 m/s
Closer to or farther from true object
Distortion of ball and cage valve
Beam width
Mech: superimposed planes
To the side of true object
Pseudo mass right atrium, echos in anechoic region
