Itzhak Kronzon et al. JIMG 2015;8:361-370 Coaxial Assessment of Valve Position and Aortic Regurgitation (A) Coaxial assessment of the valve position in relation to the aortic annulus and coronary ostia. (B) Angiographic evaluation of aortic regurgitation (AR) in the right anterior oblique (RAO) 30° angle. (C) Modified angiographic classification of AR: 1) Density of contrast is lower than in the aortic root: green zone: trivial or mild insufficiency (≤I degree), red zone: significant insufficiency (>I degree). 2) Contrast density is the same as in the aortic root: significant insufficiency (>I degree). Itzhak Kronzon et al. JIMG 2015;8:361-370 American College of Cardiology Foundation