Journal of Ultrasound in Medicine, Vol 14, Issue 7 509-513, Copyright © 1995 by American Institute of Ultrasound in Medicine
Quantitative comparison of two distinct echogenic structures appearing on the same image using gain-assisted densitometric evaluation of sonograms (GADES)
I. Blickstein, R. Goldchmit, S. D. Strano and R. D. Goldman
Department of Obstetrics and Gynecology, Kaplan Hospital, Rehovot, Israel.
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.
