The optimal report includes basic patient demographics (i.e., age, gender, and ethnicity or race) and anthropometrics. Weight and height taken at the time of the DXA scan should always be included in the report, along with their respective units (kg/lb or cm/in). It is very important to document patient height and weight since DXA measures areal, and not true volumetric, bone mineral density. As discussed previously in Chap. 6, bone density is underestimated in small patients as a result of the two-dimensional nature of the instrumentation [8, 9]. Documentation of patient size will be important for interpretation of the scans during the evaluation phase.

Body mass index (kg/m²), growth percentiles, and standard deviation Z-scores should be calculated using current growth charts. The WHO (between 1997 and 2003) completed the Multi-Center Growth Reference Study in 8500 children measured in six countries (Brazil, Ghana, India, Norway, Oman, USA). The new international growth charts (children 0–5 years) have now been adopted for use in many countries in that they represent optimal growth with no nutritional failure. In the United States and Australia, growth charts for older children include those developed by the Centers for Disease Control in 2002 [10], whereas in the United Kingdom, growth charts were recently updated (January, 2013) to combine both UK-WHO data and UK90 now simply: UK Growth Chart [11]. Examples of these growth charts are provided in Appendix B.

The demographic and anthropometric data are helpful in determining if body size is sufficiently above or below the expected range to warrant adjustment of DXA results. For those with short stature or growth delay, the ISCD recommends the use of either Bone Mineral Apparent Density (BMAD) , an estimate of volumetric BMD, or Height for age Z-score (HAZ) calculations to adjust the spine aBMD; HAZ is recommended to adjust the whole body scans [2]. Unfortunately, there are no published pediatric norms to calculate Z-scores from BMAD adjustments. Therefore, aBMD Z-scores are available only for HAZ adjustments [12]. Explanation of the modifications being made should be part of the interpretation section of the DXA report.

The report should include a brief summary of the relevant clinical history. This might include the primary medical diagnosis, the use of medications known to affect aBMD (e.g., growth hormone, certain anti-convulsants, glucocorticoids, proton pump inhibitors), fracture history, mobility status, endocrine abnormalities, pubertal status, bone age, and family history of osteoporosis. Physical activity level, dietary history, and use of vitamin or mineral supplements may also be useful.

As discussed in Chap. 5, clinical information prior to the scan improves both the acquisition and the interpretation of bone densitometry. Ideally, the patient’s medical history should be obtained directly from the referring physician. This type of information is typically gathered with a Referral or Request for Procedure form. However, some patients will be referred for bone densitometry assessment without a complete medical history.

If the referring physician has not relayed the indications for the scan and the relevant medical history, it is possible to ask the patient, parent, or both for relevant medical information. At most imaging centers, patients are asked to complete a brief registration questionnaire at the time of the DXA procedure. Examples of pediatric DXA registration questionnaires and request for procedure forms are provided in Appendix D (see also Figure 7.1).

The DXA technologist should review the questionnaire with the parent, giving particular attention to details surrounding fracture history, endocrine or growth abnormalities, orthopedic surgeries, medication and supplement usage, and family history of osteoporosis. If, for some reason, the questionnaire cannot be adequately completed at the time of examination (e.g., because of a language barrier or because the child is not accompanied by a parent) , the form can be faxed to the referring clinic for completion after the DXA procedure is completed.

Calculating changes in aBMD over time requires thoughtful consideration in pediatric patients. Although no one approach has been shown to be best, some practices can minimize error. Prior to any calculations or interpretations, scan images should be carefully examined during scan acquisition to optimize comparability of repeated measurements. Many experts believe that it is more informative to examine changes in BMC, rather than aBMD, in pediatric patients because of the variable of growth (see more detail in Chap. 6: Evaluation) [13]. In adult patients, the size of the skeleton remains relatively constant, making longitudinal comparisons of aBMD appropriate. In pediatric patients, bone growth leads to changes in bone area as well as BMC. These parameters may not increase in parallel. In fact, Bailey et al. [14] have shown that peak height velocity precedes the periods of peak bone mineral accrual by several months in teens. In recent years, there are more robust pediatric-specific reference data. However, BMC Z-scores are infrequently reported because they have yet to be incorporated into the manufacturer software. For this reason, the aBMD Z-score is typically reported and, as needed, adjusted for bone and body size.