Ultrasound is a noninvasive, safe imaging modality often used alongside X-ray to evaluate soft tissues. The ultrasound machine produces sound waves that reflect back at different rates in different tissues, and offers real-time, moving images rather than a single snapshot. The operator can move the transducer head in different directions, which produces a more three-dimensional image than X-ray. Our hospital uses ultrasound to visualize the bladder and collect urine samples, measure internal organs, look for cysts, tumors, or fluid inside the chest or abdomen, and guide needle placement to collect biopsy samples. In an experienced cardiologist’s hands, ultrasound is also the best tool for evaluating heart function.