Age determination using ultrasonography in young football players

Increasing of age cheating in sports makes problems to athletes comparable to taking illegal substances. Current method used by AFC and FIFA is applying MRI of growth plate of distal of radius to determine the bone age. This study was designed to evaluate the diagnostic accuracy of ultrasonography in bone age determination by measuring the width of growth plate in distal of radius, and comparing it with identity documents.

The study was conducted from September to December 2009 in the Department of Radiology at Al-Zahra University Hospital, Isfahan, Iran. Ultrasonography was done for 82 (15-20 years old) young professional football players and results were compared with identity documents (such as National ID card). Young football players were divided into three age categories: < 16 and > 16 years old, < 17 and > 17 years old, and < 18 and > 18 years old. Receiver Operator Characteristics (ROC) curves for discriminant values and sensitivity and specificity were analyzed.

Cut-off point was set for each group, based on the width of the growth plate, and negative test was defined as subjects < cut-off point, showing subjects over the defined age in each group. ROC curve analysis demonstrates consistently acceptable diagnostic sensitivity and specificity values in age determination of each group.

The overall predictive accuracy of ultrasonography, as described by the area under the ROC curve, was high for determination of bone age. It has an acceptable sensitivity and specificity to use for determination of age in sport competitions, and has the capability to become the screening test for age determination, especially because it is inexpensive and without any risk of radiation. It seems to be comparable with MRI in age determination.