This Article Full Text Full Text (PDF) All Versions of this Article: 90/4/1925    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wren, T. A. L. Search for Related Content PubMed PubMed Citation Articles by Wren, T. A. L. Pubmed/NCBI databases Medline Plus Health Information CT Scans Related Collections Pediatric Endocrinology Calcium and Bone Metabolism

Bone Acquisition in Healthy Children and Adolescents: Comparisons of Dual-Energy X-Ray Absorptiometry and Computed Tomography Measures

Departments of Orthopedics and Radiology and Division of Endocrinology and Metabolism, Childrens Hospital Los Angeles, Los Angeles, California 90027

Address all correspondence and requests for reprints to: Vicente Gilsanz, M.D., Ph.D., Department of Radiology, MS#81, 4650 Sunset Boulevard, Los Angeles, California 90027. E-mail: vgilsanz{at}chla.nsc.edu.

The effect that growth has on dual-energy x-ray absorptiometry (DXA) bone measurements is yet to be fully defined. The purpose of this study was to determine the best method for optimizing pediatric bone measurements using DXA. Height, weight, body mass index, skeletal age, and Tanner stage of sexual development were determined for 64 healthy boys and 60 healthy girls ages 6–17 yr. DXA of the lumbar vertebrae was performed to measure bone mineral content (BMC, grams) and areal bone mineral density (aBMD, grams per square centimeter), and geometric corrections were used to calculate volumetric bone mineral densities (vBMD): vBMD1 = aBMD/(DXA-area) and vBMD2 = aBMD/bone height. Computed tomography (CT) imaging was performed to measure volumetric bone density (vBD) and vertebral volume (Vol) and to calculate CT-BMC = vBD _* Vol. Linear regression was used to compare DXA-BMC vs. CT-BMC and CT vBD vs. DXA aBMD, vBMD1, and vBMD2. Multiple regression including the anthropometric and developmental parameters was also performed.

DXA and CT BMC were highly correlated (r² = 0.94). However, DXA aBMD correlated more strongly with CT Vol (r² = 0.68) than with CT density (r² = 0.39), and calculation of DXA volumetric densities only slightly improved the density correlations (r² = 0.49 for vBMD1; r² = 0.55 for BMD2). The correlations for density were particularly poor for subjects in Tanner stages 1–3 (r² = 0.02 for aBMD; r² = 0.13 for vBMD1; r² = 0.27 for vBMD2). In contrast, multiple regression accounting for the anthropometric and developmental parameters greatly improved the agreement between the DXA and CT densities (r² = 0.91).

These results suggest that DXA BMC is a more accurate and reliable measure than DXA BMD for assessing bone acquisition, particularly for prepubertal children and those in the early stages of sexual development. Use of DXA BMD would be reasonable if adjustments for body size, pubertal status, and skeletal maturity are made, but these additional assessments add significant complexity to the studies.

This article has been cited by other articles:

				M. L. Bianchi Diagnosis and Treatment of Bone Fragility in Childhood IBMS BoneKEy, September 1, 2008; 5(9): 323 - 335. [Abstract] [Full Text] [PDF]

				M. R. Forwood Physical activity and bone development during childhood: insights from animal models J Appl Physiol, July 1, 2008; 105(1): 334 - 341. [Abstract] [Full Text] [PDF]

				M. Misra, R. Prabhakaran, K. K. Miller, M. A. Goldstein, D. Mickley, L. Clauss, P. Lockhart, J. Cord, D. B. Herzog, D. K. Katzman, et al. Weight Gain and Restoration of Menses as Predictors of Bone Mineral Density Change in Adolescent Girls with Anorexia Nervosa-1 J. Clin. Endocrinol. Metab., April 1, 2008; 93(4): 1231 - 1237. [Abstract] [Full Text] [PDF]

				H. Vatanparast, D. A. Bailey, A. D. G. Baxter-Jones, and S. J. Whiting The Effects of Dietary Protein on Bone Mineral Mass in Young Adults May Be Modulated by Adolescent Calcium Intake J. Nutr., December 1, 2007; 137(12): 2674 - 2679. [Abstract] [Full Text] [PDF]

				L. K. Bachrach Osteoporosis in Children: Still a Diagnostic Challenge J. Clin. Endocrinol. Metab., June 1, 2007; 92(6): 2030 - 2032. [Full Text] [PDF]

				T. A. L. Wren, P. S. Kim, A. Janicka, M. Sanchez, and V. Gilsanz Timing of Peak Bone Mass: Discrepancies between CT and DXA J. Clin. Endocrinol. Metab., March 1, 2007; 92(3): 938 - 941. [Abstract] [Full Text] [PDF]

				G. L. Klein, L. K. Bachrach, and I. A. Holm Effects of Pharmacologic Agents on Bone in Childhood: An Editorial Overview Pediatrics, March 1, 2007; 119(Supplement_2): S125 - S130. [Full Text] [PDF]

				V. Gilsanz and T. Wren Assessment of Bone Acquisition in Childhood and Adolescence Pediatrics, March 1, 2007; 119(Supplement_2): S145 - S149. [Abstract] [Full Text] [PDF]