MDCT evaluation of sternal development.

BACKGROUND AND PURPOSE

Sternal ossification starts in utero, and continues throughout puberty in various patterns. In this study, our objective was to evaluate the correlation of ossification with age and to determine whether age can be predicted.

MATERIALS AND METHODS

Individuals younger than 30 years old without congenital anomalies, chronic disease, and history of long-term chemotherapy who had chest CT imaging with a slice thickness < 3 mm were retrospectively reviewed. Data of ossification centers, horizontal and vertical fusion were collected. Spearman correlation test and ROC analysis were performed to correlate age with fusion. Kruskal-Wallis test was used to perform gender wise comparisons. Sensitivity, specificity, positive predictive value and negative predictive value of cut-off points, estimated according to ROC analysis, were calculated.

RESULTS

Segmented ossification centers were more common in males, with significant difference in third and fourth mesosternal ossification centers (p < 0.05). Females had more vertical fusion at each level (p < 0.05). Spearman correlation test showed significant correlation between age and horizontal and vertical fusion for both genders. ROC analysis was performed and cut-off values were estimated. Sensitivity was very high (84.6-100%) but specificity was low (43.3-79.9%) for horizontal fusion. Sensitivity of vertical fusion (64.8-100%) was similar but specificity was higher (74.7-100%).

CONCLUSIONS

Horizontal and vertical fusions of sternal ossification centers correlate with age significantly. Vertical fusion might be a better indicator of age with higher sensitivity and specificity, while horizontal fusion has lower accuracy. Large-scale studies should be conducted to confirm our results.