Transesophageal echocardiography uses

Transesophageal echocardiography produces very high resolution images, because the probe is so close to the heart and thoracic aorta.
It is especially useful for assessing the native and prosthetic mitral valve, recognizing intracardiac masses such as atrial thrombi and endocardial vegetations, and diagnosing aortic dissection. It is also useful during surgery to monitor left ventricular wall motion, intracardiac air, and to assess surgical results.

Transesophageal echo - 4 chamber view

The transesophageal echocardiograms that follow are from other patients who do have left atrial appendage thrombi.

Transesophageal echo - 4 chamber view

This is a still frame of a 4-chamber transesophageal echocardiogram in the transverse plane that clearly shows a stenotic mitral valve. the dilated left atrium is superior and the left ventricle is inferior to the mitral valve.
In the real-time study that follows, note the restricted motion of the thickened mitral valve leaflets typical of rheumatic heart disease, and the swirling “smoke-like” appearance in the left atrium consistent with stagnant blood flow.

Transesophageal echo - Aortic valve level

This is a still frame of a transesophageal echocardiogram in the transverse plane at the level of the aortic valve. the left atrium and triangular-shaped atrial appendage are dilated, and the appendage is filled with a large thrombus.
In the real-time study that follows, note that the thrombus is immobile.

Colorized transesophageal echo - Aortic valve level

This is a still frame of a transesophageal echocardiogram in the transverse plane at the level of the aortic valve. when colorization is added, subtle morphologic features seen in black and white may become enhanced. this study clearly shows the triangular-shaped left atrial appendage filled with multiple thrombi.
In the real-time study that follows, note the oscillations of these mobile thrombi.