Ultrasonography uses high-frequency (ultrasound) waves bounced off internal structures to produce a moving image. It uses no x-rays. Ultrasonography of the heart (echocardiography) is one of the most widely used procedures for diagnosing heart disorders because it provides excellent images and is
Ultrasonography is also used in the diagnosis of disorders affecting blood vessels in other parts of the body.
Echocardiography can be used to detect whether the heart muscle is moving normally and how much blood the heart is pumping out with each beat. This procedure can also detect abnormalities in the heart's structure, such as defective heart valves, birth defects (such as holes in the walls between the heart's chambers), and enlargement of the heart's walls or chambers, as occurs in people with high blood pressure, heart failure, or impairment of the heart's muscular walls (cardiomyopathy).
Echocardiography can also be used to detect pericardial effusion, in which fluid accumulates between the two layers of the sac that envelops the heart (pericardium), and constrictive pericarditis, in which scar tissue forms throughout the pericardium. It also detects dissection of the aorta, a tearing within the layers of the wall of the aorta.
The main types of ultrasonography are
Two-dimensional ultrasonography, the most widely used technique, produces realistic two-dimensional images in computer-generated "slices." "Stacking" the slices together can re-create a three-dimensional structure.
Doppler ultrasonography shows the direction and velocity of blood flow and thus can detect turbulent flow due to narrowing or blockage of blood vessels.
Color Doppler ultrasonography shows the different rates of blood flow in different colors.
Doppler ultrasonography and color Doppler ultrasonography are commonly used to help diagnose disorders affecting the heart and the arteries and veins in the trunk, legs, and arms. Because these procedures can show the direction and rate of blood flow in the chambers and blood vessels of the heart, they enable doctors to evaluate the structure and function of these parts. For example, doctors can determine if the heart valves open and close properly, if and how much they leak when closed, and if blood flows normally. Abnormal connections between an artery and a vein or between heart chambers can also be detected.