Geometric and intensity distortion in echography

Ruptured gel-filled silicone breast implants: sonographic findings in 19 cases.

“…Therefore, one sees the boundary between the silicone and the breast parenchyma and structures behind the boundary, which appear normal but are actually in the wrong position. This is what happens when sound is focused behind cysts in routine clinical sonograms, but only to a greater degree [9,10]. This explanation also accounts for bulges in implants not producing the noisy appearance, as in the walled-off leak shown in Figure 5.…”

Geometric distortion of area in medical ultrasound images

“…Then, the distance within the object will be misrepresented in the image and the refraction at the object boundary will not be accounted for, both of which will contribute to the geometric distortion of the object's image. While this effect has been predicted previously [4,5,6,7,8,9], a quantitative understanding is lacking. Such understanding is important in establishing errors in clinical measurements, and devising corrective strategies.…”

The retrolenticular afterglow: an echo enhancement artifact.

“…The factor F corrects for the fact that some of the backscattered sound on its return trip through the lens to the transducer is refracted out of the plane of the sonogram; F depends upon R, N, and the location of the scatterer, and has the dimension of reciprocal length. 7 Although not explicitly appearing in this equation, Y (the vertical position on the sonogram) is incorporated through its relationship with 6, i.e., Y R sin 6…”