Echocardiography (echo) provides information on the size, shape, and movement of various parts of your heart. These components include the heart valves, the septum (the wall that separates the right and left heart chambers), and the heart chamber walls. Doppler ultrasonography visualizes the flow of blood via your heart. This technique can also be used to measure pressure within the heart chambers. Echo scans use sound waves to create images of your heart. They are very safe and do not involve any radiation exposure. The echocardiographer performs the scan by placing special transducers on your chest wall where they transmit acoustic signals into your heart. The echoes from these pulses are then collected by a second set of transducers placed on your chest wall or in your hand. Information about the size and shape of your heart chambers is derived from measuring the time it takes for the pulse to travel between each pair of sensors. Color flow imaging adds detail to the standard two-dimensional image by showing the direction and speed of blood flow through your heart chambers. This allows the echocardiographer to see how well your heart's valves function and to identify potential blockages.