Can ultrasound be used to estimate bone mineral density in children with growth problems?

Aim To assess predictability of bone mineral density ( BMD ) of the lumbar spine ( LS ) determined by dual‐energy x‐ray absorptiometry ( DXA ) using by ultrasound speed of sound of the right and left radii ( SOS ‐ R and SOS ‐ L ) in patients with growth problems. Methods Ultrasound and DXA were compared in patients with advanced, normal and delayed bone ages assessed by G reulich and P yle ( GP ) and T anner and W hitehouse ( TW 3) methods. Results There was a strong correlation (r), of raw scores, between SOS ‐ R and SOS ‐ L , r = 0.81, p = 0.000 and their respective Z ‐scores, r = 0.78, p = 0.000. Z ‐score correlations were poor between SOS ‐R or SOS ‐ L and LS ‐ BMD . Sensitivity, specificity, positive and negative predictive values of SOS ‐ R and Z ‐scores for predicting normal (>−1 to <1) and low (<−1) LS ‐ BMD were poor. For high (>1) LS ‐ BMD , Z ‐scores were 22%, 93%, 29% and 90%, respectively, for SOS ‐ R and for SOS ‐ L , 25%, 89%, 20% and 91%. For very low (<−2) LS ‐ BMD , SOS ‐ R and SOS ‐ L were the same, respectively, 29%, 91%, 40% and 86%. Conclusion Ultrasound of the radius is a poor predictor of radiologically assessed BMD at the LS , especially with delayed bone age.