Peripheral nerve morphometry: Comparison between manual and semi-automated methods in the analysis of a small nerve

Morphometry of saphenous nerve in young rats

“…Alpsan and Lal (1980) used a totally manual technique to perform the morphometric study of the myelinated fiber. It is well known that manual morphometry is tedious, time consuming, difficult to perform correctly and subject to many sources of errors (Vita et al, 1992;Auer, 1994;Silva et al, 2007). Alpsan and Lal (1980) have previously classified the saphenous nerve myelinated fibers into 1 m size groups by comparing their total diameter with holes etched in a Perspex stencil and then, fibers were measured by a compass.…”

“…Nevertheless, manual intervention was allowed by the program when necessary. Morphometry was performed on a semi-automated basis (Silva et al, 2007). Morphometric parameters of the fascicles and the myelinated fibers of the saphenous nerve segments were obtained as described previously for other nerves (Fazan et al, 1997(Fazan et al, , 1999Jeronimo et al, 2005;Rodrigues-Filho and Fazan, 2006).…”

Binary imaging analysis for comprehensive quantitative histomorphometry of peripheral nerve

“…Digitizing tablets were used extensively before the availability of robust computing power, and have been used to validate previously published semiautomated histomorphometric methods (Usson et al, 1991;Vita et al, 1992;Urso-Baiarda and Grobbelaar, 2006;Silva et al, 2007). For evaluation on the digitizing tablet, a photomicrograph of a non-injured sciatic nerve section, taken at 1000× and comprising approximately 100 axons, was printed on an HP Laserjet 4350n printer.…”

“…The thresholding technique to define myelin has been used in several previously described histomorphometry methods (Torch et al, 1989;Usson et al, 1991;Vita et al, 1992;Auer, 2004;Romero et al, 2000;Urso-Baiarda and Grobbelaar, 2006;Silva et al, 2007). Accurate thresholding is perhaps the most essential step in the program; under-thresholded images will underestimate myelin area, and over-thresholded images will overestimate myelin area secondary to excessive highlighting of non-myelin features.…”

Recurrent laryngeal nerve post-natal development in rats

“…A photomicrograph of the whole nerve transverse section was obtained with the aid of an Axiophot I photomicroscope (Carl Zeiss, Gena, Germany), and magnified to 1.300×. Morphometry was performed on the micrographs, with the aid of a digitizing tablet and an image analysis system (MINI MOP; Kontron Bildanalyse, Munich, Germany) as described elsewhere (Fazan and Lachat, 1997;Silva et al, 2007). Briefly, the internal area of each fascicle (excluding the perineurium) and the diameter of each myelinated fiber and their respective axon were measured.…”