Multidetector computed tomography (MDCT) is expected to revolutionize the way the evaluation and work-up of the cardiac patient is performed. Although invasive coronary and cardiac angiography maintains a 0.2-mm spatial resolution versus 0.4-mm in 64-slice MDCT, the emergence of retrospectively electrocardiographic-gated 64-slice MDCT has resulted in high spatial resolutions that are not achievable with other noninvasive cardiac imaging modalities. The purpose of this article is to describe the MDCT qualitative techniques used to evaluate valvular lesions and to describe and illustrate a spectrum of congenital and acquired valvular disease with 64-slice MDCT.
Cardiac valvular disease is a cause of considerable morbidity and mortality. In 2006, the total estimated mortality attributable to valve disease in the United States was 19,989 deaths. Aortic valve disease accounted for 12,471 deaths, and mitral valve disease for 2759 deaths, with the remainder divided evenly between the tricuspid and pulmonary valves.
Transthoracic and transesophageal echocardiography are the primary imaging modalities used to evaluate valve disease, although in some patients it may be difficult to obtain accurate visualization and evaluation of valvular lesions.2 User-operator dependency is an inherent disadvantage, and some patients have an inadequate acoustic window for scanning. Transesophageal echocardiography is an invasive procedure and is contraindicated in patients with recent esophageal surgery, recent oral ingestion, unstable cervical spine injuries, and unevaluated gastrointestinal bleeding. Although cardiac magnetic resonance imaging (MRI) is currently regarded as the noninvasive reference standard for valve evaluation, it is costly, time-consuming, and has limited availability. Contraindications for MRI include pacemakers, implantable cardiac defibrillators, intravascular stents <6 weeks after implantation, aneurysmal clips, heart valves installed before 1996, and claustrophobia.
Multidetector-row computed tomography (MDCT) is an emerging modality in noninvasive cardiac imaging. Using data acquired throughout the cardiac cycle, it is possible to reconstruct multiple reconstructions at 10% increments of the R-R interval. These can then be combined sequentially to provide functional imaging data sets in a cine loop that allows evaluation for valvular leaflet morphology and function. The purpose of this article is to describe the cardiac MDCT techniques that allow optimal depiction of the cardiac valves, describe the pathophysiology of a spectrum of valvular diseases, and illustrate their appearances on 64-slice MDCT.