Computed tomography and magnetic resonance imaging assessment of aortic valve stenosis: an update

Computed tomography (CT) and magnetic resonance imaging (MRI) are being increasingly utilized for the evaluation of cardiac valves. Although echocardiography is the first-line imaging modality in the evaluation of aortic stenosis (AS), CT and MRI can be adopted as adjunct imaging modalities for assessing the severity of AS. First, CT has established its role in the evaluation of co-existing coronary artery disease in AS patients, while stress MRI can be employed to exclude myocardial perfusion abnormalities. For the pre- and post-procedural evaluation of transcatheter aortic valve implantation or replacement, CT plays a very important role in determining the size of prosthetic valves and evaluating post-procedural complications. CT also helps assess the prosthetic valve sizes with 3-dimensional printing. Late gadolinium enhancement, T1 mapping, and feature tracking of left ventricular myocardium enable assessment of left ventricular function and myocardial fibrosis in patients with AS. Four-dimensional flow analysis gives new insights on flow patterns, kinetic energy, and wall shear stress in the ascending aorta in AS patients. In summary, CT and MRI are playing increasingly important roles in the evaluation of aortic valve disease.