Ultrasound Artifacts and Image Characteristics

28 vocabulary flashcards covering ultrasound image characteristics and common artifacts.

Hyperechoic

Structure that appears brighter than the surrounding tissues because it reflects more sound.

Hypoechoic

Structure that appears darker than surrounding tissues due to reduced echo amplitude.

Anechoic

Area without echoes that appears completely black on the image, often representing fluid.

Homogeneous

Region displaying similar echoes throughout, indicating uniform tissue composition.

Heterogeneous

Region containing a variety of echo intensities, indicating mixed tissue composition.

Artifact

Any image error produced by equipment malfunction, physics limitations, or user operation.

Reverberation Artifact

Series of multiple, equally spaced parallel lines (“ladder”) caused by repeated reflections between two strong interfaces.

Refraction Artifact

Lateral displacement of a reflector because the sound beam bent when crossing a tissue interface.

Grating Lobe Artifact

Extra echoes placed side-by-side, produced by off-axis beams from array transducers.

Shadowing

Does not result from placement of too many echos

Signal drop-out deep to a highly attenuating or reflecting structure where the beam cannot pass.

Enhancement

Increased brightness deep to a weak attenuator (e.g., fluid) because of low attenuation through the structure.

Does not result multiple enhancements.

Mirror Image Artifact

Causes replica deeper than image.

Duplicate structure appearing deeper than the true reflector on the opposite side of a strong specular reflector.

Axial Resolution Artifact

Failure to distinguish two reflectors that are too close together along the beam’s path.

Slice-Thickness Artifact

The bean dimension is greater than reflector size.

False echoes produced when the beam’s height is thicker than the reflector, filling a structure that should be anechoic.

Grating Lobe Artifact

Artifact incorrect number of reflector side-by-side

What eliminate lobe artifacts

Apodization and subdicing

Subdicing

Dividing each array element into smaller sub-elements to minimize grating lobes.

Ring-Down Artifact

Single, solid, hyperechoic line parallel to the sound beam produced by resonating gas bubbles.

Edge Shadow

Refraction-related shadow that appears at the edges of a curved or circular structure.

Focal Enhancement (Focal Banding)

Too much gain at focal zone

Array Transducer

Multi-element transducer capable of electronic steering and focusing; can produce grating lobes.

Range Ambiguity Artifact

Reflector placed too shallow because echoes from a deeper pulse return after the next pulse is emitted; corrected by increasing PRP.

Speckle

Granular, noisy texture caused by constructive and destructive interference of echoes from many small scatterers.

Speed (Range) Error Artifact

Incorrect depth display when propagation speed differs from 1540 m/s; faster speed places reflector shallow, slower deep.

Ghosting

Color-Doppler “flash” produced by slow tissue or wall motion that contaminates the flow display.

Multipath Artifact

If path two reflectors is different distance returning, it will have incorrect position on display

Incorrect reflector position when pulses bounce off a secondary structure and travel a longer or shorter path before returning.

Where does enhancement occur?

Lower attenuation, deeper than the weak attenuator