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Updated: Oct 15, 2026
Cortical Bone Assessment Using Ultrasonic Guided Waves: A Reproducibility Study in a Healthy Population
Published on: January 31, 2025
A prospective cross-sectional diagnostic feasibility study: musculoskeletal ultrasound for pediatric bone age
Xingxu Zhou1, Yifei Huang1, Chunrong Liu2
1Department of Ultrasound, Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
Background:
Ultrasonography offers several advantages in medical diagnostics, including the absence of radiation exposure, convenience, and real-time dynamic imaging. In this study, radiographic bone age assessment based on left-hand wrist X-rays was used as the reference standard to evaluate the feasibility and association with radiographic bone age of ultrasound for bone age estimation.
Methods:
This study was designed as a prospective cross-sectional diagnostic feasibility study. Children who underwent radiographic bone age assessment using left-hand wrist X-rays at a large tertiary hospital were enrolled. 139 children (63 boys and 76 girls) aged 3-16 years were recruited. Within 7 days, ultrasound examinations were performed on the metacarpals and phalanges of the first, third, and fifth fingers, as well as the ulna, radius, and femur. The longitudinal diameters of the ossification centers and epiphyses were measured, and the ossification ratio [OsR = ossification center length/epiphyseal length (d/D)] and skeletal maturity score (SMS) were calculated for each bone.
Results:
Ultrasound imaging clearly showed the ossification centers and epiphyseal cartilage. Radiographic bone age was correlated with the SMS of the metacarpals, phalanges, ulna, radius, and femur, with the strongest correlation observed between radiographic bone age and the combined skeletal maturity score (CMS) of the ulna, radius, and femur [boys: r=0.961, 95 % confidence interval (CI) 0.936-0.977; P<0.001; girls: r=0.962, 95 % CI: 0.940-0.976; P<0.001]. The URF (ulna + radius + femur) combination demonstrated the highest intraclass correlation coefficient (ICC) values and 95 % CIs in both the inter-observer and the intra-observer assessments, with an ICC of 0.99 and a 95 % CI of 0.98-1.00.
Conclusions:
In this study, the CMS of the URF were strongly correlated with Tanner-Whitehouse 3 radius-ulna-short bone (TW3-RUS) radiographic bone age, suggesting that ultrasound has potential research value in pediatric bone age assessment. Because agreement and prediction-error analysis was not performed, feasibility and association with radiographic bone age of this examination method for pediatric bone age assessment requires further validation through subsequent large-sample agreement studies.
