Study on Assessment of the Diameter of Thoracic Aorta by Computed Tomography of Chest

Abstract

INTRODUCTION: Computed tomography (CT) is frequently used for the evaluation of different aortic diseases which is a good method of measuring the aortic diameter. Thus, knowledge of normal aortic diameters is very important in the assessment of aortic disease. METHODS: This was a prospective cross sectional study done on 105 patients who presented in department of Radiodiagnosis in Lumbini Medical College, Palpa, Nepal from February 5th 2022 to February 4th 2023. Plain helical scan was performed using Siemens Somatom 16 slice CT scanner. CT images were obtained in supine position with full inspiration. Diameters of the aorta was measured at the level of aortic valve sinus, ascending aorta, proximal to innominate artery, transverse aortic arch, distal transverse aortic arch, aortic isthmus and descending aorta at the level of diaphragm perpendicular to the axis of the aorta. RESULTS: Diameter of thoracic aorta was found to be maximum at ascending aorta with mean of  2.85 cm, followed by aortic valve sinus 2.80 cm, 2.68 cm at proximal to innominate artery, 2.57 cm at proximal transverse arch, 2.41 cm at distal transverse arch, 2.24 cm at isthmus and 2.03 cm at descending aorta at the level of diaphragm. There was smooth tapering of aortic diameter from ascending aorta onwards. There was a significant correlation of mean ascending aorta diameter with the age of the patients(r = 0.475, p< 0.05). CONCLUSION: Diameter of thoracic aorta was found to be maximum at the level of the ascending aorta and minimum at the level of diaphragm. The diameter of thoracic aorta had significant correlation with the age of patients.