[Possibilities and limits of 2-dimensional echocardiography in quantitative image analysis]

By two-dimensional echocardiography left ventricular volumes can be measured and ejection fraction can be calculated. But volume and ejection fraction determination are combined with a systematic underestimation despite high correlation in comparison to "true volume", whereas cineventriculography systematically overestimates true volume. This echocardiographic methodological problem is related not only to tangential scanning but also to low lateral resolution yielding a reduced endocardial border delineation. Meanwhile, advanced transducer technology and digital imaging techniques with zoom and cineloop possibilities have improved endocardial border detection. In comparison to cineventriculography, volume determination by two-dimensional echocardiography has improved significantly in comparison to results in 1983; this improvement was mainly due to a better determination of endsystolic volume. Similarly, left ventricular contrast echocardiography using color coding with statistical analysis of digitized images enhanced the accuracy of analysis of global and regional left ventricular function. Transesophageal echocardiography will be used when there is reduced image quality of transthoracic echocardiography, for example, in obese patients or those with pulmonary emphysema or mechanical ventilation. Transthoracic echocardiography has become a routine method for assessing global and regional left ventricular function. Echoventriculography can be used in patients with renal insufficiency, anaphylactic reaction to contrast medium, and poor left ventricular function.