European Journal of Radiology 71 (2009) 432–439 Contents lists available at ScienceDirect European Journal of Radiology journal homepage: www.elsevier.com/locate/ejrad Of small bones and big mistakes; bone densitometry in children revisited R.R. van Rijn a,∗ , C. Van Kuijk b a Department of Radiology, Emma Children’s Hospital/Academic Medical Center Amsterdam, The Netherlands b Department of Radiology, Free University Amsterdam, The Netherlands article info Article history: Received 28 August 2008 Accepted 29 August 2008 Keywords: Bone densitometry DXA Children abstract In this paper we discuss the bone densitometry systems available and their applicability in children and adolescents. Based on the knowledge that the majority of bone densitometry studies in children are performed using dual-energy X-ray absorptiometry (DXA), we focus attention on the sources of errors in interpretation of DXA studies in children and adolescents. © 2009 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Up to a decade ago bone densitometry was thought to be an area of interest primarily of concern to those involved with adult patients. In this population osteoporosis is a disease with signifi- cant clinical and socio-economic implications. It is estimated that 10 million Americans, aged 50 years and over, have osteoporosis and that each year approximately 1.5 million people will suffer an osteoporotic fracture [1]. These fractures have detrimental effect on health and quality of life of the patients affected, as 20% of patients who suffer a hip fracture will die within 1 year. Osteoporosis-related fractures account for a significant amount of medical expenditure and according to the Surgeon General the direct costs in the United States range from 12.2 to 17.9 billion dollars annually [1]. Paediatricians, and others involved in children’s health care, might consider ‘how does this concern me?’ However, in 1973 Pro- fessor Charles Dent originally postulated that ‘senile osteoporosis is a paediatric disease’ and this concept has been subsequently supported by others [2–7]. The importance of achieving maximum peak bone mass (PBM), i.e. the highest bone mineral density (BMD) achieved in young adulthood, is recognised as an important fac- tor in the prevention of osteoporosis in later life. Furthermore, there are a multitude of childhood diseases which have a known adverse effect on bone mass accrual and bone health (Table 1). In the light of the concept of the importance of attaining maximum PBM and with an increasing number of therapeutic regimens aimed at increasing and/or maintaining bone mass in children and adoles- ∗ Corresponding author at: Department of Radiology, Academic Medical Centre Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam Zuid-Oost, The Netherlands. Tel.: +31 20 5669111; fax: +31 20 5669119. E-mail address: r.r.vanrijn@amc.uva.nl (R.R. van Rijn). cents, more paediatricians are managing children in whom BMD is, or will become, of clinical relevance [8,9]. This implies that pae- diatricians will also have to become involved in, or at least have knowledge of, bone densitometry. In this review we will discuss the most widely used bone densitometry techniques and intro- duce some specific paediatric problems and their implications with respect to the interpretation of bone densitometry studies. 2. Bone densitometry techniques To date all bone densitometry techniques have been designed almost exclusively for, and validated in, application in adults. This has lead to a high level of knowledge concerning bone densitom- etry in this population in those involved in performing the BMD measurements. Specific problems, either related to the bone den- sitometry technique in use or related to patient characteristics, do exist when these techniques are applied in children (Table 2). Unfor- tunately, these problems have received relatively little attention until recent years, possibly leading to over and/or under treatment of children due to erroneous classification/diagnosis [10–12]. In the following section four bone densitometry techniques are discussed, for each technique the strengths and limitations in relation to the use in children are presented. Although the use of magnetic resonance imaging (MRI) for bone densitometry and imaging bone structure has been described in research studies in adults, the relative lack of MR availability, cost of imaging and the need for sedation in young children makes this technique currently applicable only in a research setting and rarely in children. There- fore, the use of MRI will not be included in this paper. 0720-048X/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2008.08.017