Estimation of cardiac chamber size by routine chest radiography and echocardiography

The size of the left atrium and both ventricles was estimated by routine chest radiography and compared to echocardiographic single-chamber measurements. Left atrial size correlated well, but echocardiography appeared to be considerably more sensitive in detecting enlargement. Estimates of left ventricular size by radiography and echocardiography showed considerable discrepancy, since the single-dimension echocardiographic technique does not reflect lateral or inferior enlargement, which is readily visible on the radiography; however, ultrasound can distinguish left ventricular hypertrophy from dilatation. Right ventricular size cannot be assessed accurately using the single-diameter technique. The authors suggest that a combination of both techniques would be more accurate than either modality alone and that two-dimensional cardiac studies should prove more reliable than the single-diameter method.