Quantitative comparison of two distinct echogenic structures appearing on the same image using gain-assisted densitometric evaluation of sonograms (GADES).

Abstract

Gain‐assisted densitometric evaluation of sonograms with two distinct echogenic structures appearing on each image was performed to establish if their density‐gain setting curves have similar inclinations. We used the breast model (n = 67) in which hyperechoic masses were compared to the surrounding hyperechoic tissue at the optimal gain (Gopt) and at Gopt + 5. Both structures had significantly different film‐corrected densities and showed a linear decline of density as the system gain increased from Gopt ‐ 5 to Gopt + 5. The least squares regression lines were almost parallel. The density‐gain unit decrease from Gopt ‐ 5 to Gopt was not different, but the decrease from Gopt to Gopt + 5 reached statistical significance. The data suggest that skewed values are theoretically possible in comparing two distinct echogenic structures. However, within the gain intervals used in GADES, these differences are negligible and comparisons are as accurate as with the assessment of a single echogenic structure.

Computed Sonography: Requiem to Echogenicity Assessment?

“…Similarly, imaging a given tissue at a constant LC but at a different gain setting significantly changes the image density. These differences are greater than the dif ferences between fetal lung and liver or between fetal liver and bowel [2] and surely greater than the subtle differ ences between breast lesions and surrounding tissue [12]. Using relative echoes, i.e., comparing two echogenicities appearing on the same image, is commonly used to assess echogenicity.…”

“…Using relative echoes, i.e., comparing two echogenicities appearing on the same image, is commonly used to assess echogenicity. It has been shown that skewed values of image density are possible in comparing two distinct cchogenic structures appearing on the same image when produced in a given gain range [12], Moreover, we recent ly established that human vision is inadequate to discern isodensity or density differences in the range of those between fetal bowel and fetal liver [ 13].…”