Echocardiography (echo) is the use of ultrasound to image the heart. A complete echocardiographic examination evaluates cardiac chambers, valves, wall motion, pericardium, and great vessels using a combination of 2D B-Mode, M-Mode, spectral Doppler, and color Doppler. Echocardiography is the primary imaging tool for diagnosing valvular heart disease, cardiomyopathy, pericardial disease, congenital heart defects, and assessing cardiac function. Cardiac sonographers (echocardiographers) hold RDCS or RCS credentials.