Chest radiograph is an easily available non invasive tool in evaluation of health. The cardiothoracic ratio (CTR) is commonly used as an indicator of cardiomegaly in clinical radiology. It can promptly diagnose congestive cardiomegaly apart from other lung and pleural pathologies and also depicts repsonse to treatment given, like diuretics in heart failure. Although there are better modalities available like echocardiography, computed tomography and magentic resonance imaging, chest radiography and cardiothoracic ratio are still being used by clinicians, especially in emergency department, intensive care unit and for frequent follow ups . CTR is calculated by dividing the cardiac diameter (CD) by the thoracic diameter (TD) as measured on posteroanterior chest radiography (chest PA). CTR of >0.5 is abnormal on an inspiratory breath-hold chest radiograph. The purpose of this study was to compare the statistical correlation of CTR between chest radiograph with CT and to present real Heart Size (HS), Thoracic Size (TS), and Cardiothoracic Ratio (CTR) on chest PA and chest AP in the DR system and in computed tomography (CT). The conclusion of the study is that the measurement of CTR from radiograph & computed tomography (CT) from both axial & coronal reformations were concordant with another