Eur J Pediatr (1996) 155 : 377-382 9 Springer-Verlag 1996 Nicoletta Zamberlan Giorgio Radetti Claudio Paganini Davide Gatti Maurizio Rossini Vania Braga Silvano Adami Evaluation of cortical thickness and bone density by roentgen microdensitometry in growing males and females Received: 28 April 1995 Accepted: 25 August 1995 S. Adami (~) Cattedra di Reumatologia, Ospedale di Valeggio, 1-37067 Valeggio (Verona), Italy Fax: +39 +45 7950188 N. Zamberlan - D. Gatti 9 M. Rossini V. Braga 9 S. Adami Cattedra di Reumatologia, Universit~ degli Studi di Verona, Italy G. Radetti 9 C. Paganini Divisione di Pediatria, Ospedale Civile di Bolzano, Italy Abstract The bone mineral content (BMC) and the cortical thickness at the distal radius and at the II metacarpal were assessed in growing individuals (167 females and 158 males) by radiometric and quantita- tive roentgen microdensitometric methods. BMC adjusted for age and pubertal status was significantly higher in males than in females. However, the BMC corrected for bone volume (volumetric bone den- sity, g/cm 3) and the metacarpal corti- cal index (cortical area/total area) were identical in males and females. BMC rose progressively with age, approaching a plateau by the end of puberty. Lower but still significant increases with age were also ob- served for volumetric bone density of the metacarpus and the metacarpal index. These increases were also most marked by the end of pubertal maturation and might be related to diminution of bone turnover. Key words Bone mineral content 9 Children 9 Cortical thickness 9 Pu- berty - Roentgen microdensitometry Abbreviations BD bone density 9 BMC bone mineral content 9 BMCr bone mineral content of ultradistal radius 9 CV coefficient of variation 9 DEXA dual-energy X-ray absorptiometry 9 MI metacarpal index 9 QCT quantitative computed tomography 9 vBD volumetric bone density Introduction Osteoporotic fractures are related to bone mass and den- sity (BD), which depend on both the rate of bone loss with ageing and the bone mass present around the fourth decade of life. The latter basically coincides with the peak bone mass attained at maturity. Its variance is such that it may explain a large proportion of osteoporotic risk in postmenopausal women [12]. The variance in peak bone mass is explained not only by hereditary factors but also by intercurrent diseases, di- etary habits, physical exercise and hormonal status, which are susceptible to some kind of intervention. This poten- tial intervention is conceivable only if normative data on growing individuals are available. The densitometric methods are precise but scarcely avail- able. Another common problem in interpreting data from bone mass measurements arises in children with growing skeletal size, since densitometric methods evaluate the bone mineral content (BMC) but not the volumetric density. This can be measured accurately only by quantitative computed tomography (QCT), which cannot be used extensively in children for its cost and for the excessive X-ray exposure.