Gray scale refers to the spectrum of brightness levels used to display ultrasound images, ranging from pure black (representing no echoes or very weak echoes) through various shades of gray to pure white (representing the strongest echoes). Modern ultrasound systems typically use 256 shades of gray to create detailed images of body structures. The ability to distinguish subtle differences in gray scale is essential for diagnostic sonography, as many pathological conditions produce only slight changes in tissue echogenicity that may be difficult to detect. Understanding gray scale helps sonographers optimize image quality through appropriate gain, dynamic range, and contrast settings.
Sonography Term