The retrolenticular afterglow: an echo enhancement artifact

Area of Science:

• Medical imaging
• Acoustics
• Mathematical modeling

Background:

• Ultrasound imaging often displays refractive artifacts.
• The behavior of ultrasound beams interacting with objects of differing sonic speeds is complex.
• Circular objects can act as lenses, influencing wave propagation.

Purpose of the Study:

• To develop a mathematical model for sonograms of circular objects with lower sonic speeds.
• To explain observed refractive artifacts.
• To predict and identify a novel ultrasound artifact.

Main Methods:

• Construction of a mathematical model simulating ultrasound interaction with a circular object.
• Experimental design using a tissue-equivalent phantom with an ethyl alcohol-filled cylindrical well.
• Sonographic analysis to observe predicted artifacts.

Main Results:

• The model accurately predicted refractive artifacts caused by the lens-like effect of the circular object.
• A new artifact, termed the retrolenticular afterglow, was predicted and observed.
• The afterglow appears as a region of increased echogenicity distal to the object.

Conclusions:

• Circular objects with lower sonic speeds can cause significant artifacts in ultrasound imaging.
• The retrolenticular afterglow is a newly identified artifact in sonography.
• This finding enhances the understanding of ultrasound wave behavior and artifact generation.