What is a bicuspid aortic valve (BAV)?
This is the most common congenital cardiovascular abnormality, with a prevalence of up to 2% in the general population and occurring more commonly in males. This includes a spectrum of aortic valve deformities where either two (rather than three normal) cusps are present, or three developmental anlagen of cusps and commissures are present where two adjacent cusps fuse into a single aberrant cusp with development of a ridge or raphe. A BAV is associated with an increased risk of aortic stenosis, aortic regurgitation, infective endocarditis, ascending aortic aneurysm formation, and aortic dissection due to coexistent aortopathy and is also associated with coarctation of the aorta, PDA, and coronary artery anomalies.
On CT, a BAV may be seen as having two cusps of equal size and two commissures (i.e., hinge points), along with a typical “fish-mouth”–shaped aortic valve orifice during systole and a single line of coaptation during diastole. Alternatively, two of three underdeveloped cusps of the aortic valve may be seen to be conjoined with formation of a raphe, which are together larger in size than the third uninvolved cusp. Calcification of the raphe or valve leaflets may also be present and is sometimes visible on a chest radiograph.