X Ray Body Measurement
X ray electromagnetic radiation of extremely short wavelength and high frequency with wavelengths ranging from about 10 8 to 10 12 metre.
X ray body measurement. Body composition measurement in 9 11 y old children by dual energy x ray absorptiometry skinfold thickness measurements and bioelectrical impedance analysis. Dual energy x ray absorptiometry dexa body composition measurement can be assessed using a dexa machine which stands for dual energy x ray absorptiometry. Thus analysis of x ray images of the body is a valuable medical diagnostic tool. Dexa machines are able to differentiate body weight into the components of lean soft tissue fat soft tissue and bone based on the differential attenuation by tissues of two levels of x rays.
An x ray or x radiation is a penetrating form of high energy electromagnetic radiationmost x rays have a wavelength ranging from 10 picometres to 10 nanometres corresponding to frequencies in the range 30 petahertz to 30 exahertz 310 15 hz to 310 18 hz and energies in the range 124 ev to 124 kevx ray wavelengths are shorter than those of uv rays and typically longer than those of. The intraclass correlation coefficient icc bland altman procedure and spearman rank correlation were used to determine test retest reliabilities of the three methods and to compare methods. Dual energy x ray absorptiometry dxa skinfold thickness and bioimpedance analysis bia. American journal of clinical nutrition 63 287 292.
The objective of this study was to compare dual energy x ray absorptiometry dxa with the criterion 4 compartment model 4 cm for measurement of bf in a large pediatric cohort and to assist pediatricians in appropriate interpretation of body composition information by recognizing differences between techniques. We compared in 9 11 y old children n43 three measures of body composition. From the calcaneus dual energy x ray absorptiometry dxa scan images the region representing the ultrasound measurement area was found to contain cortical bone edges in 60 of cases. In 16 of scans a small part 45 40 of the roi measurement area fell partially outside the heel.
Dual energy x ray absorptiometry is the most widely used and most thoroughly studied bone density measurement technology.