Ultrasound technology has a variety of uses in modern medicine. They are frequently used as a powerful diagnostic imaging tool for both the detection of change in internal organs and for neonatal imaging during pregnancy. Ultrasound works by sound waves that bump into each other, causing vibrations in tissues, that create energy. At certain wavelengths, this can create an image. At other, therapeutic wavelengths, these sound waves that cause microscopic air bubbles stimulate cell membranes and promote healing. At the proper wavelengths, therapeutic ultrasound elevates tissue temperature, increasing circulation, loosens tightened tissue, and increases cell metabolism. These changes result in decreased inflammation, decreases in muscle spasms, facilitation of tissue healing, decreased scarring, and muscle relaxation.