title: Reproducibility in nerve morphometry: comparison between methods and among observers.
abstract: We investigated the reproducibility of a semiautomated method (computerized with manual intervention) for nerve morphometry (counting and measuring myelinated fibers) between three observers with different levels of expertise and experience with the method. Comparisons between automatic (fully computerized) and semiautomated morphometric methods performed by the same computer software using the same nerve images were also performed. Sural nerves of normal adult rats were used. Automatic and semiautomated morphometry of the myelinated fibers were made through the computer software KS-400. Semiautomated morphometry was conducted by three independent observers on the same images, using the semiautomated method. Automatic morphometry overestimated the myelin sheath area, thus overestimating the myelinated fiber size and underestimating the axon size. Fiber distributions overestimation was of 0.5  μ m. For the semiautomated morphometry, no differences were found between observers for myelinated fiber and axon size distributions. Overestimation of the myelin sheath size of normal fibers by the fully automatic method might have an impact when morphometry is used for diagnostic purposes. We suggest that not only semiautomated morphometry results can be compared between different centers in clinical trials but it can also be performed by more than one investigator in one single experiment, being a reliable and reproducible method.
authors.affiliation: Department of Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil.
authors.forename: Antônio Paulo da Costa
authors.initials: AP
authors.lastname: Bilego Neto
authors.forename: Fernando Braga Cassiano
authors.initials: FB
authors.lastname: Silveira
authors.forename: Greice Anne
authors.initials: GA
authors.lastname: Rodrigues da Silva
authors.forename: Luciana Sayuri
authors.initials: LS
authors.lastname: Sanada
authors.forename: Valéria Paula Sassoli
authors.initials: VP
authors.lastname: Fazan
mesh_terms: D000818:Animals; D001369:Axons; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D009186:Myelin Sheath; D009413:Nerve Fibers, Myelinated; D009929:Organ Size; D051381:Rats; D015203:Reproducibility of Results; D012984:Software; D013497:Sural Nerve / Q000033:anatomy & histology*