Abstract

Background: Chest radiography is an important method of imaging, providing an cheap, accessible and effective diagnostic tool. Aortic knuckle is an important finding in chest radiography. Aortic knuckle enlargement suggests underlying cardiovascular comorbidity including diabetes mellitus and hypertension.
Aims and objectives: To analyze the contribution of aortic knuckle to left cardiac outline in normal population and compare with the patients suffering from cardiovascular comorbidity in Postero-anterior (PA) chest radiography.
Materials and methods: Postero-anterior (PA) chest radiography of 648 individuals between the ages of 18 to 75 years were evaluated. Curved length of aortic knuckle (AKC) and total length of left cardiac outline (LCOT) were studied and contribution of aortic knuckle to left cardiac outline in normal population versus the patients suffering from cardiovascular comorbidity was analyzed. Statistical analysis was carried out with the help of IBM-SPSS (IBM Corporation) and Microsoft Excel.
Results and Conclusion: Curved length of aortic knuckle (AKC) and total length of left cardiac outline (LCOT) were analyzed to compare normal population with those with cardiovascular co-morbidity. The contribution of aortic knuckle to left cardiac outline was 18.4% in normal population and 25.5% in co-morbid patients. Thus, simple measurement of aortic knob in PA chest x-ray may help in predicting cardiovascular comorbidity.