All ultrasounds have gain control. It’s often a knob, button, and/or a series of sliders on the console, and it’s one of the most used and adjusted scanning parameters... but do you know what it really does?
Most people think of gain as a brightness adjuster, and while it’s true that turning your gain up will brighten the image, it’s helpful to understand how it actually works. Gain is a uniform amplification of the ultrasonic signal that is returning to the transducer after it travels through the tissue. So rather than brightening the monitor, the image on the screen is whitened by a uniform margin, as though the returning signal is stronger than it is, to make it easier to see.