Registration of serial transverse sections of muscle fibers

Background: Structural and functional characterization of skeletal muscles is often assessed by histochemical techniques, which enable the classificat ion into different fiber types by combining the reactions in serial transve rse muscle cross-sections. A drawback is that a knowledgeable operator is r equired to combine and evaluate the reactions, which is a time-consuming, t edious, and subjective task. To enhance the speed and reproducibility of mu scle fiber typing, the registration of serial transverse sections of muscle fibers images has been proposed as a preprocessing step. Methods: Three different registration methods were considered: first, a sem i-automatic elastic point-based registration; second, an automatic (rigid, affine, and projective) whole image content-based registration; and, third, an automatic hierarchical elastic registration obtained by integration of the first two methods. The performances of the methods were tested on a dat abase of 50 image stacks each containing three images of histochemically di ffer entry stained serial human muscle cross-sections. Results: The amounts of successful globally and locally registered stacks were approximately 20 % for automatic rigid registration, 60% for automatic affine and projective registrations, and 80% for semiautomatic and automatic elastic registratio n. Conclusions: By using robust elastic registration methods, the automatic re gistration of serial transverse muscle fiber images seems feasible and migh t allow automatic muscle fiber typing, and consequently, improve the charac terization of skeletal muscles. Cytometry 37:93-106, 1999. (C) 1999 Wiley-L iss, Inc.