The standard clinical applications of echocardiography involve display of the smooth surfaces of the
heart, such as the endocardium, epicardium and valve leaflets. A relatively new area of endeavor in cardiac ultrasound
is the attempt to evaluate myocardial tissue composition and/or structure based on the acoustic properties of
the heart. The rationale for this area of study - termed ultrasound tissue characterization - is that ultrasound
interacts (is absorbed or reflected) differently with abnormal myocardium than with normal myocardium. This
rationale stems from the common clinical observation that certain abnormalities of the heart (calcification, amyloidosis,
and others) affect the appearance of échocardiographie images. Several approaches to the evaluation of
tissue composition with ultrasound include the display of acoustically abnormal tissue using gray scale or color
encoding, the measurement of classical acoustic variables, and computer-based analysis of ultrasound signals and
images. Promising results have been obtained through the use of ultrasound tissue characterization methods to
identify acute ischemia, acute and chronic myocardial infarction, cardiomyopathies, myocardial contusion, and
intracardiac masses. Although many technical problems remain to be solved, ultrasound tissue characterization may
soon be added to the routine diagnostic armamentarium of the cardiologist.