Computer-aided three-dimensional reconstruction: a method of measuring temporal bone structures including the length of the cochlea.

To visualize the three-dimensional (3-D) shapes of structures in the temporal bone from histologic sections, we developed computer software to create computer-generated 3-D images from two-dimensional (2-D) materials. Using those images, we have been able to measure these structures in three dimensions. This means that quantitative 3-D measurements can be performed regardless of the angle at which the specimen was cut. This report describes this method for 3-D reconstruction and measurement and discusses its implications. For instance, in addition to showing the 3-D shape of the cochlea from different angles, we have been able to measure the length of the cochlea and have shown that measurements made by use of the conventional 2-D graphic reconstruction method can be distorted considerably by variations in cutting angle of the specimen.