Towards assessment of regional wall stress of the left ventricle using 3D ultrasound imaging

In order to assess regional left ventricular wall stress in vivo, endocardial surface (SI) and epicardial surface (S2) have been acquired with commercially available 3D ultrasound equipment. Subsequently, SI and S2 have been divided into 16 overlapping areas of interest (AOI). To each of these 16 AOIs an ellipsoid is fitted and the principle radii of this ellipsoid are used to describe the principle radii of the AOI. Wall thickness for each AOI is found by computing the volume between S1 and S2 at each AOI and dividing this by the computed surface of the AOI. Using this algorithm the principal radii and wall thickness have been assessed for an ellipsoid phantom, which both correlated well with the values found for the ideal, mathematically constructed shape.