Diagnostic medical sonography, also known as ultrasound, is a diagnostic medical imaging modality used to assist in medical diagnoses and image-guided procedures. Sonography is performed by placing a transducer with gel on the human body. The transducer emits high-frequency sound waves into the body. These sound waves reflect from organs and body fluids, which in turn produce an image on the ultrasound machine. These images aid in guiding diagnosis and treatment of pregnancy and diseases such as cirrhosis, hyper/hypothyroidism, polycystic ovarian syndrome, and nephrolithiasis. Sonographers are highly skilled professionals who have learned the art and science of sonography and who work under the guidance of physicians to facilitate diagnosis.