Évolution avec l'âge des tailles des espaces et des travées dans l'os spongieux de l'enfant étudiée par mesure automatique

Measurements of trabecular bone structure in man (for radionuclide dosimetry

“…I n general, the results of Lloyd and Hodges show the same trend as for the 44 year old male, but mean trabecular path lengths are greater and mean cavity path lengths smaller. This could result from the measurement directions used by these authors, or possibly from over-estimation of the more opaque component (bone) due to the section thickness used (Witmer 1969). The number of directions and sections scanned is particularly important; for example, if unidirectional scanning only is used, our results suggest that the mean path lengths so derived can differ by as much as 50% from the omnidirectional mean path lengths, depending on the bone, section and direction scanned.…”

“…As far as path-length distributions are concerned there is only one reported study with which meaningful comparison can be made. Witmer (1969) and Le Grand and Witmer (1971) report measurements made in two directions on cervical vertebrae in children ranging in age from birth to 2 years, and also present one cavity distribution measured on the cervical vertebra of a 30 year old male. This distribution is similar at large path lengths to that of the 44 year old male presented here, but departs markedly at path lengths below 200 pm.…”