Bone age assessments by quantitative ultrasound (SonicBone) and hand X-ray based methods are comparable

Background: Bone maturation is currently assessed by subjective and automated radiography. Objectives: To evaluate the concordance and reproducibility of a quantitative ultrasound (QUS) based device versus X-ray based methods. Methods: The study population comprised 150 children, 76 males, 4–17 years of age. X-ray scans were evaluated according to wrist, carpal, and phalanx areas for bone age. QUS was performed by the the BAUS™ device (SonicBone, Rishon Lezion, Israel), using speed-of-sound (SOS) and distance attenuation factor (ATN) in similar areas. Data from 100 subjects were used to establish the device conversion equation, and 50 measurements were assigned to assess inter-modality agreement. Results: BAUS showed high repeatability performance, 0.73% relative standard deviation for SOS and 3.5% for ATN. R² for the conversion equation including gender, SOS, and ATN was 0.80 for all methods (P < 0.001). There was no significant bias in bone age assessments. Conclusions: Bone age assessment by SonicBone is comparable to the assessment by X-ray based methods.