Correlation between chest radiography and echocardiography in evaluation of heart size

The diagnosis of cardiomegaly by a frontal chest film compared to echocardiography was prospectively studied in 48 patients. Twenty-three patients had radiographic evidence of heart enlargement. The methods used for radiographic evaluation of the heart size included subjective assessment, cardiothoracic ratio, frontal cardiac area, and cardiac diameter. Echocardiographic examination was used as the reference method. Cardiomegaly as assessed by the different methods used for chest film measurements had a sensitivity of 60-100%, and a positive predictive value of 23-47% for left ventricular mass. The positive predictive value of the chest film measurements increased to 44-75% when enlargement of any chamber measured in echocardiography was used for reference. Cardiothoracic ratio and heart diameter had fair correlation (r = 0.62) with left ventricular mass. They showed high sensitivity (90% and 100%, respectively) and can serve as survey methods for the detection of cardiomegaly.