ObjectiveTo find the relationship between bicuspid aortic valve (BAV) and the dilatation or aneurysm of the aorta using electrocardiogram-gated computed tomography angiography (CTA). MethodsWe collected the clinical data of the BAV coexisting with suspected aortic dilatation or aneurysm from February 2012 through April 2015. A total of 124 patients were analyzed retrospectively. There were 97 males and 27 females at an anverage age of 50.35±16.26 years. According to the CTA, patients were classified into two groups: a pure BAV(without raphe) group and a BAV (with raphe) group. we recorded the aortic diameters, gender, age, and so on. ResultsOf the 124 patients, 91 (73.4%) had BAV with raphe, and 33 patients (26.6%) had pure BAV. The analysis revealed that the diameter of the annulus (23.90±3.34 mm vs. 21.74±3.46 mm, P=0.005), the sinuses of Valsalva (40.93±6.78 mm vs. 37.35±7.06 mm, P=0.022), the tubular portion of the ascending aorta (45.38±7.66 mm vs. 38.29±8.18 mm, P=0.0001), and the part of the aorta proximal to the innominate artery (34.19±4.98 mm vs. 30.23±6.62 mm, P=0.02) between patients with BAV with raphe and pure BAV had significant differences. And there was a significant difference in prevalence of dilatation of the aorta between patients with pure BAV and BAV with raphe [77/91 (84.6%) vs.18/31(58.1%), P=0.004]. Of the 91 BAV with raphe patients, we found 76 patients (83.5%) with right and left coronary cusps (R-L) fusion, 13 patients (14.3%) with right and non-coronary cusps (R-N) fusion, and 2 patients (1.2%) with left and non-coronary cusps (L-N) fusion. There was a statistical difference in the aortic root diameters between R-L fusion BAV and R-N fusion BAV. The diameter of the distal ascending aorta and proximal aortic arch between R-L and R-N fusion BAV had statistical differences. ConclusionsBAV with raphe is more common than pure BAV and is more often associated with dilatation and aneurysm of the ascending aorta. Otherwise R-L fusion BAV is associated with increased diameters of the aortic root, while R-N fusion BAV is associated with increased diameters of the distal ascending aorta and proximal arch.