The LV surface is then divided into 16 segments. Regional shape in each segment is calculated as the mean radial distance from the center axis of all points in that segment. Regional shape analysis is based on the regional mean distance of LV segments from the center axis. This technique is useful for diagnosing, stratifying, and bioengineering modeling of a wide variety of cardiac diseases, including post-infarct remodeling, ventricular aneurysm, congenital malformations, and cardiomyopathy. Quantitative Mitral Annular Shape Mitral annular size and shape parameters can be measured from the Fourier-derived reconstructions used to model them.
Area is indexed to body surface area.
To calculate eccentricity, an ellipse approximating the annulus is constructed by matching its centroid and second moment of inertia to those of the area enclosed in the annular curve as projected onto the least-squares plane. Annular height, interpeak span, and intervalley span are measured as shown below. These measurements have been validated in phantoms in vitro . Although the analyses were developed initially for application to data acquired from rotational transesophageal echo scans, the measurements can also be made from transthoracic 3D echo scans. 3D conceptualization of the mitral annulus as a nonplanar ring with local maxima anteriorly and posteriorly.