Studies of cardiac function and myocardial tissue characterization

The heart can be studied using ultrasound techniques. The shape of the hear t, its chambers, wall thicknesses, wall tissue characteristics as well as m otion of walls and valve leaflets are all diagnostic information. In additi on, the blood velocity and its timing within the cardiac cycle is an import ant diagnostic tool. In the present paper focus will be limited to the anal ysis of the left ventricular function as observed with two-dimensional and three-dimensional echocardiography and the characteristics of backscattered ultrasound information from the left ventricular chamber wall. Function of the heart is often studied by observation of local wall motion or comparis on of chamber volume in maximum and minimum shapes during the cardiac cycle (ejection fraction). Integrated backscatter from the wall is described in examples of cardiac transplantation and hypertrophy. Study of cyclic variat ion of frequency-dependent attenuation and integrated backscatter indicates that these are independent parameters.