Use of dual energy X-ray absorptiometry in pediatric patients

Abstract

Dual Energy X-ray Absorptiometry (DXA) is a vital tool for assessing bone health in patients at risk for fragility fractures. In pediatric patients, this technology is used in conjunction with clinical fracture history to diagnosis osteoporosis and monitor treatment response. Childhood and adolescence is characterized by linear growth and bone mass accrual; thus there are important differences in the interpretation of bone measurements obtained by DXA in these young patients. This review aims to explore the current indications for DXA use and interpretation of DXA in the pediatric age group using currently available reference databases. Limitations of DXA in pediatric patients, specifically in children with short stature, will be explored. We will review several pathophysiologic mechanisms that may lead to low bone density in children, discussing representative diseases and the recommendations for monitoring bone health with DXA in these conditions. Finally, we will highlight new methods by which DXA imaging can gather additional information on bone health in children and may improve our ability to predict fractures and osteoporosis.

Severity of reduced bone mineral density and risk of fractures in long‐term survivors of childhood leukemia and lymphoma undergoing guideline‐recommended surveillance for bone health

“…We adjusted BMD z-scores for height in patients aged 4 to 20 years using the method described by Zemel et al, 29 which has been shown to be least biased for age and height-for-age compared with other methods. 26,29,34,35 Low BMD was defined as >1 SD (z-score less than −1) and very low BMD as >2 SDs (z-score less than −2) below age-matched, sex-matched, and race-matched norms, consistent with prior studies in childhood cancer survivors. 13,[36][37][38][39][40]…”

“…52 Also, our definition of low BMD is consistent with prior studies by others in survivors. 23,26,27,29,[31][32][33][34][35][36][37][38][39][40]53 An important consideration is the clinical implications of identifying reduced BMD. The COG long-term follow-up guidelines recommend survivors with/at risk of decreased BMD conduct regular weight-bearing activity and ensure adequate vitamin D/calcium intake through diet or supplementation.…”

“…Age‐matched, sex‐matched, and race‐matched BMD z‐scores were determined by comparing them with reference standards provided by the manufacturer (Hologic Inc). We adjusted BMD z‐scores for height in patients aged 4 to 20 years using the method described by Zemel et al, which has been shown to be least biased for age and height‐for‐age compared with other methods …”

Bone Density in Children With Chronic Liver Disease Correlates With Growth and Cholestasis

“…DXA is a two‐dimensional projection technique that summarizes total bone mass within the projected bone area. This measurement of areal BMD (grams per square centimeter) is known to systematically underestimate volumetric BMD (grams per cubic centimeter) in children with poor growth, and various methods have been used to adjust for body size . In light of this intrinsic limitation of DXA analysis and the fact that in our study cohort we observed a strong correlation between DXA measurements and anthropometrics (Table ), we elected to adjust for height and weight using the method of Short et al Although the ALGS and CIC participants were similar with respect to weight, height, and BMI Z scores, only the ALGS group showed a significant normalization of DXA Z scores after anthropometric adjustment.…”

Mandibular Cortical Width on Panoramic Images of Children in the Lao People’s Democratic Republic

“…Osteoporosis is usually diagnosed by measuring bone mineral density (BMD) of the spine or femur. Dual energy X-ray absorptiometry (DXA) is recommended for precise diagnosis of low bone mass [8][9][10][11] . No DXA equipment is currently available in Laos.…”