Figure 16a. Bicuspid aortic valve stenosis with poststenotic dilatation. (a) Early-phase oblique sagittal MIP image shows an aneurysm of the ascending aorta. The presence of underlying valvular disease cannot be determined with contrast-enhanced MR angiography. (b) Oblique coronal cine MR image shows the bicuspid nature of the aortic valve in this patient (arrowhead). (c) Coronal systolic cine MR image shows an area of signal void due to underlying aortic stenosis (arrow). (d, e) In-plane (d) and through-plane (e) velocity-encoded cine MR images allow calculation of the gradient through the valve. Gadolinium-enhanced MR angiography should be used in conjunction with traditional spin-echo and cine MR angiography to optimize evaluation of the thoracic aorta.