Advanced Analysis Techniques Improve Infant Bone and Body Composition Measures by Dual-Energy X-Ray Absorptiometry.

OBJECTIVE: To evaluate a novel technique designed to reduce the negative impact of motion artifacts in infant dual-energy X-ray absorptiometry (DXA) scans. STUDY DESIGN: Using cross-sectional data from a large multicenter study, we developed and tested advanced methods for infant scan analysis. Newborns (n = 750) received spine and whole-body DXA scans with up to 3 attempts to acquire a motion free scan. Precision of infant DXA was estimated from visits with multiple valid scans. Accuracy of regional reflection, fusion, and omission techniques was estimated by comparing modified scans to unmodified valid scans. The effectiveness of the acquisition and analysis protocol was represented by the reduction in rate of failure to acquire valid results from infant visits. RESULTS: For infant whole-body DXA, arm reflection and all fusion techniques caused no significant changes to bone mineral content, bone mineral density, bone area, total mass, fat mass, lean mass, and percentage fat. Leg reflection and arm/leg dual-reflection caused significant changes to total mass, but the percentage change remained small. For infant spine DXA, fusion and omission caused no significant changes. Advanced analysis techniques reduced the failure rate of whole-body scanning from 20.8% to 9.3% and the failure rate of spine scanning from 8.9% to 2.4%. CONCLUSIONS: Advanced analysis techniques significantly reduced the impact of motion artifacts on infant DXA scans. We suggest this protocol be used in future infant DXA research and clinical practice.

Diffuse idiopathic skeletal hyperostosis association with thoracic spine kyphosis: a cross-sectional study for the Health Aging and Body Composition Study.

STUDY DESIGN: A descriptive study of the association between diffuse idiopathic skeletal hyperostosis (DISH) and kyphosis. OBJECTIVE: To investigate the association of DISH with Cobb angle of kyphosis in a large cohort of older subjects from the Health Aging and Body Composition Study. SUMMARY OF BACKGROUND DATA: DISH and thoracic kyphosis are well-defined radiographical findings in spines of older individuals. Characteristics of DISH (ossifications between vertebral segments) reflect changes of spine anatomy and physiology that may be associated with Cobb angle of kyphosis. METHODS: Using data from 1172 subjects aged 70 to 79 years, we measured DISH and Cobb angle of kyphosis from computed tomographic lateral scout scans. Characteristics of participants with and without DISH were assessed using the χ² and t tests. Association between DISH and Cobb angle was analyzed using linear regression. Cobb angle and DISH relationship was assessed at different spine levels (thoracic and lumbar). RESULTS: DISH was identified on computed tomographic scout scan in 152 subjects with 101 cases in only the thoracic spine and 51 in both thoracic and lumbar spine segments. The mean Cobb angle of kyphosis in the analytic sample was 31.3° (standard deviation = 11.2). The presence of DISH was associated with a greater Cobb angle of 9.1° and 95% confidence interval (95% CI) (5.6-12.6) among African Americans and a Cobb angle of 2.9° and 95% CI (0.5-5.2) among Caucasians compared with those with no DISH. DISH in the thoracic spine alone was associated with a greater Cobb angle of 10.6° and 95% CI (6.5-14.7) in African Americans and a Cobb angle of 3.8° and 95% CI (1.0-6.5) in Caucasians compared with those with no DISH. CONCLUSION: DISH is associated with greater Cobb angle of kyphosis, especially when present in the thoracic spine alone. The association of DISH with Cobb angle is stronger within the African American population.