Ultrasonography

Ultrasonography is a diagnostic imaging technique used with organs and regions, and as a part of diagnosis of diseases. It does not include therapeutic ultrasound.

The technique physically involves sending acoustic energy from a transducer, far above the human hearing range (1.6 to 20 MHz), into the area of interest, receiving reflections of that energy, and converting the image to clinically useful images.

Examinations of different parts of the body, for different reasons, have different names, optimal frequencies, means of display, and places to apply the transducer. For example, an echocardiogram visualizes the heart. When the transducer is applied to the chest, the result is a transthoracic echocardiogram, but if the transducer is placed in the esophagus, the study becomes a transesophageal echocardiogram(TEE). In addition, either of these viewing techniques can be done after the heart has been stressed by exercise or drugs; the latter view would be called a "stress TEE".