The third generation ultrasound contrast agents (UCA/USCA) are more echogenic and stable, and are able to enhance the echogenicity of parenchyma on B-mode images. These microbubbles may thus show perfusion, even in such a difficult region as the myocardium.

See also History of Ultrasound Contrast Agents.

(TTE) Transthoracic echocardiography is a common type of cardiac ultrasound and is used to evaluate the size and function of the heart.

Indications:
TTE requires no sedation or special patient preparation. After the application of ECG electrodes and ultrasound couplant, the probe is maneuvered over the chest in the area adjacent to the breast bone and under the left breast, to provide the different views of the heart. Usually the images will be obtained lying relaxed on the left side. Other views can be sampled lying on the back with the knees bent, or sitting in an upright position.

See also Bicycle Stress Echocardiography and Transesophageal Echocardiography.