Boyle OK. Anatomical and radiological evaluation of the variation in the branching patterns and morphology of the aortic arch in the irish population-A morphometric study. Int J Anat Var. 2019;12(4): 40-45.Introduction: Anatomical variations of the aortic arch are clinically significant for diagnostic and surgical procedures in the mediastinum. Our objective was to determine the arch morphology and incidence of variant branching patterns in both a cadaveric and patient population.Materials and Methods: 194 CT scans were retrospectively analysed for branching variations and arch type. 18 cadavers were dissected with variations noted.Results: Analysis of scans revealed normal branching in 77.32%, bovine arch pattern in 14.43%, direct origin of the left vertebral artery in 7.73% and a bovine arch with direct origin of the left vertebral artery in 0.52%. A significant correlation (p<0.0001) was found between arch type and age, with the mean age of a type 1 arch 51.1 years, type 2 arch 60.7 years, and type 3 arch 70.7 years. Direct origin of the left vertebral artery was found in one cadaver.Conclusion: Correlation between arch type and age strengthens the concept of age-related unfolding of the aortic arch. A detailed understanding of the branching variations of the arch is important in the disciplines of anatomy, radiology and cardiothoracic surgery. characteristics in both a cadaveric and patient population. Through the use of dissection and computed tomography, clinically relevant morphometric data was gathered which can be applied to both the diagnostic and surgical field.