Ultrasound devices are often associated with pregnancy sonograms, although it is one of the more popular applications of ultrasound technology it's not the only one. Ultrasound devices generally are used for therapeutic or diagnostic reasons. Diagnostic applications are much more versatile and effective. One of the reasons ultrasound diagnosis is very popular is that it has no risk associated with it, unlike x-ray diagnosis for example. The no risk factor is crucial for pregnant women, children, and other at-risk patients. Depending on the diagnostic application; be it for the kidneys, liver, heart, or abdomen different probes or transducers are used. There are several knobs and buttons on ultrasound devices that control different parameters such as modes, frequencies, gain, depth, etc. These parameters are changed to obtain the best axial resolution so physicians can give accurate diagnoses.