The use of a computerized algorithm to determine single cardiac cell volumes

Single cardiac muscle cell volume data have been difficult to obtain, especially because the shape of a cell is quite complex. With the aid of a surface reconstruction method, a cell volume estimation algorithm has been developed that can be used on serial sections of cells. The cell surface is reconstructed by means of triangular tiles so that the cell is represented as a polyhedron. When this algorithm was tested on computer generated surfaces of a known volume, the difference was less than 1·6%. Serial sections of two phantoms of a known volume were also reconstructed and a comparison of the mathematically derived volumes and the computed volume estimations gave a per cent difference of between 2·8% and 4·1%. Finally cell volumes derived using conventional methods and volumes calculated using the algorithm were compared. The mean atrial muscle cell volume derived using conventional methods was 7752·7 ± 644·7 μm3, while the mean computerized algorithm estimated atrial muscle cell volume was 7110·6 ± 625·5 μm3. For AV bundle cells the mean cell volume obtained by conventional methods was 484·4 ± 88·8 μm3 and the volume derived from the computer algorithm was 506·0 ± 78·5 μm3. The differences between the volumes calculated using conventional methods and the algorithm were not significantly different.