| 主权项 |
1. A computer-implemented process for calculating the volume of a cavity surrounded by a cavity wall, wherein the cavity is a heart chamber, the method comprising the steps of:
a) accessing at least one of several three-dimensional image data record/records of the cavity or one of several stack/s of two-dimensional images of the cavity; b) creating a preliminary deformable surface model of the interior surface or an exterior surface of the cavity wall for each 2D image data record or each stack of 2D images, respectively; c) dividing the surface of the preliminary surface model into surface segments; d) defining volume segments each including one surface segment and extending radially inwards and/or outwards from their associated surface segment; e) statistical analysis of grey levels of voxels in a specified volume range on both sides of the surface of the preliminary surface model and therefrom identifying the volume proportions of cavity wall, cavity—interior space and/or exterior space in the respective volume segments, wherein the statistical analysis determines a histogram of grey levels and gives an a posteriori probability for a voxel within the volume range to represent a point of the cavity wall, the cavity interior space and/or the exterior space, f) calculating the blood volume in the cavity interior space, the volume of the cavity wall and/or the volume of the exterior space in a volume segment by weighted integration of the voxels in the volume segment, wherein the volume of each voxel is weighted with the a posteriori probability of cavity interior space, cavity wall, and/or exterior space in the respective volume segment, as determined by the statistical analysis; wherein the method is carried out by a central processing unit of a computer. |
