MAPPING OF THE ORIENTATION OF MYOCARDIAL-CELLS BY MEANS OF POLARIZED-LIGHT AND CONFOCAL SCANNING LASER MICROSCOPY

The study of the topological organisation of myocardial cells is a bas ic requirement for the understanding of the mechanical design of the n ormal and pathological heart. We developed a technique based on multip arametric image analysis of transmitted polarized light to generate ma ps of the azimuth and the elevation angles of the myocardial cells. Th e properties of birefringence of the myocardium embedded in methylmeta crylate were measured in papillary muscles with monitored 3D orientati on. This birefringence is positive uniaxial with a 0 degrees extinctio n angle when the axis of the fiber is parallel to the axis of the pola rizer or the analyzer. Thick sections were studied between crossed pol ars, and four images of each section were digitized for an angle of th e polarizer with the section varying from 0-67.5 degrees in steps of 2 2.5 degrees. The amounts of transmitted light for each setup of the po larizer were combined in order to extract the values of the azimuth an gle (module 90 degrees) and the elevation angle of the myocardial cell s, according to the Johannsen equation. The respective maps of these a ngles were calculated and then assessed with confocal scanning laser m icroscopy. This method provides an efficient and accurate tool for the study of the histological architecture of the fetal and neonatal hear t. (C) 1995 Wiley-Liss, Inc.