Comparison of sensitivity and specificity of cardiac size estimation through plain chest x-rayand two ecocardiography

<p><strong>BACKGROUND: </strong>Despite more accurate methods of cardiac imaging, plain chest X-ray (CXR)</p><p>still is the first imaging method in people with suspected heart diseases. The most important</p><p>application of CXR in cardiac patients is the estimation of cardiac size. There are two main</p><p>methods for cardiac estimation in CXR; transverse diameter (TD) and calculation of cardiac</p><p>width ratio to thoracic cage or cardiothoracic ratio (CTR). Echocardiography is a standard and</p><p>more accurate method for cardiac size measurement; however, it requires more time and is</p><p>costly,and is not as accessibleas CXR.</p><p><strong>METHODS: </strong>This study aimed to determine the sensitivity and specificity of CXR to diagnose</p><p>enlarged heart (cardiomegaly) in comparison with echocardiography. In this study, 327 adults</p><p>that referred for echocardiography to Hajar Hospital(Shahrekord, Iran) during summer 2001</p><p>were recruited. Their CXR findings were compared to echocardiography.</p><p><strong>RESULTS: </strong>Mean age of the patients was 53.6 years and 46% were male. Considering the CTR &le;</p><p>50% of thoracic cage widthand TD &le; 16 cm as normal,CTR resulted in 28.2% false-positiveand</p><p>9.2% false-negative classification for cardiomegaly.The corresponding figures for TD were</p><p>8.8%and 58.5%, respectively.</p><p><strong>CONCLUSION: </strong>In order to determine cardiomegaly, CTR had a higher sensitivity in</p><p>comparison with TD; however, the specificity of TD was higher than CXR.</p><p><strong>Keywords: </strong>Echocardiography, Plain Chest X-Ray, Cardiac Size.