Normal Bone Mineral Density (BMD) Comparison Set

BMD datasets are machine-specific, therefore the correct DXA manufacturer must be selected. Please note the age ranges available for the instruments (see below-right, or refer to the graphs). If you enter an out-of-range age, your entry will not be accepted and the calculated values will not be updated.

Options

1. Instrument: QDR1000 QDR2000 QDR4500 Delphi Discovery V12 Lunar
2. Bone Site: Lumbar Spine Femoral Neck Trochanter Whole Body

Subject Values

1. Gender: Female Male
2. Age (years):
3. BMD (g/cm^2):
4. DXA Wt (kg):
   (Wt required for Discovery V12 whole body)

Calculate

BMD Results

1. Z-Score:
2. Percentile:

Bone Site

1.  

Instructions for use

Available Age Ranges:

HOLOGIC
Spine: 8 - 17 yrs
Femoral Neck: 8 - 17 yrs
Trochanter: 8 - 17 yrs
Whole Body: 2 - 22 yrs

GE/LUNAR
Spine: 4 - 22 yrs
Femoral Neck: 5 - 19 yrs
Trochanter: 5 - 19 yrs
Whole Body: 4 - 22 yrs

Hologic Data
Hologic values are adjusted to a common instrument model (QDR2000) prior to Z-score calculation.
Discovery V12 (and higher versions) incorporate the Auto-WB analysis adjustment that affects bone results for children weighing less than 40 kg (Shypailo, 2005). The DXA Weight field must be entered for this instrument and version.

GE/Lunar Data
Lunar values are based on the DPX model. Reference data accumulated on Lunar pencil-beam densitometers can be used as reference data for newer models such as the Prodigy (Oldroyd, 2003).

What is DXA BMD

Bone Mineral Density, as measured by DXA, represents a two-dimensional areal density. Increases in BMD in children are associated with skeletal growth as well as increasing lean tissue mass; however, BMD is dependent on bone size, thus smaller children, or children with impaired growth, may have relatively small BMD values. This needs to be taken into account when using age as a comparative index.

In order to help interpret the calculated Z-score, it may be useful to review a child's growth as compared to the normal population. Visit the Pediatric Growth References page where you can plot a child's weight and height on the normal growth curves, and to calculate the associated percentiles.

 

Reference Data

This Z-score calculator uses an array of means and standard deviations indexed by age, and all input ages are rounded off to the nearest whole number. Therefore, even though the graph will plot an age of 10.5, for example, an age of 11 would be used in the calculations.

Data used to produce these charts come from published references and from the CNRC Body Composition Laboratory Normal Child Database. All values are machine-dependant.

 

To cite this source

Ellis KJ, Shypailo RJ (2001) Body Composition Comparison Data for Children. Retrieved from the Baylor College of Medicine, Children's Nutrition Research Center, Body Composition Laboratory Web Site:
http://www.bcm.edu/bodycomplab/Applications/zscrmainpage.htm

References:

Data generated by the Body Composition Laboratory at the Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX.

Supporting publications:

DeSchepper J, Derde MP, Van den Broeck M, Piepsz A, Jonckheer MH. Normative data for lumbar spine bone mineral content in children: influence of age, height, weight, and pubertal stage. J Nucl Med 1991;32:216-220.

Ellis KJ, Shypailo RJ, Hardin DS, Perez MD, Motil KJ, Wong WW, Abrams SA. Z score prediction model for assessment of bone mineral content in pediatric diseases. J Bone Miner Res 2001;16(9):1658-1664.

Faulkner RA, Bailey DA, Drinkwater DT, Wilkinson AA, Houston CS, McKay HA. Regional and total body bone mineral content, bone mineral density, and total body tissue composition in children 8-16 years of age. Calcif Tissue Int 1993;53:7-12.

Geusens P, Cantatore F, Nijs J, Proesmans W, Emma F, Dequecker J. Heterogeneity of growth of bone in children at the spine, radius, and total skeleton. Growth, Dev Aging 1991;55:249-256.

Lu PW, Howman-Giles R, Briody J, Morley K, Humphrie I, Allen J, Cowell CT, Sillence D. Bone mineral density of total body, spine, and femoral neck in normal children. J Bone Miner Res 1992;7(Sup 1):S258.

McCormick DP, Ponder SW, Fawcett HD, Palmer JL. Spinal bone mineral density in 335 normal and obese children and adolescents: evidence for ethnic and sex differences. J Bone Miner Res 1991;6:507-513.

Oldroyd B, Smith AH, Truscott JG. Cross-calibration of GE/Lunar pencil and fan-beam dual energy densitometers - bone mineral density and body composition studies. EJCN 2003;57:977-987.

Ponder SW, McCormick DP, Fawcett HD, Palmer JL, McKernan MG, Brouhard BH. Spinal bone mineral density in children aged 5.00 through 11.99 years. Am J Dis Child 1990;144:1346-1348.

Shypailo RJ, Ellis KJ. Bone assessment in children: Comparison of fan-beam DXA analysis. J Clin Densitom 2005;8(4):445-453.

van der Sluis IM, de Ridder MA, Boot AM, Krenning EP, de Muinck Keizer-Schrama SM. Reference data for bone density and body composition measured with dual energy x ray absorptiometry in white children and young adults. Arch Dis Child 2002;87:341-347.

Southard RN, Morris JD, Mahan JD, Hayes JR, Torch MA, Sommer A, Zipf WB. Bone mass in healthy children: measurement with quantitative DXA. Radiology 1991;179:735-738.