Journal of Ultrasound in Medicine, Vol 2, Issue 3 117-121, Copyright © 1983 by American Institute of Ultrasound in Medicine
Effect of display format on detectability
D. I. Thickman, M. C. Ziskin and N. J. Goldenberg
The effects of black-echo (black dots on white background) and white-echo
(white dots on black background) display formats on detectability of a wire
embedded in an echogenic test object were compared. Trained observers were
asked to note the presence or absence of the wire on a randomized series of
528 B scans (264 black-echo and 264 white-echo images), half of which
contained a wire. The scans not containing a wire were used as controls.
The specificity of the white-echo display (75 per cent) exceeded that of
the black-echo display (54 per cent), with statistical significance at the
99 per cent confidence level. There was no measurable difference in
sensitivity. These results are explained in terms of principles of visual
physiology.
