Objective To explore the MRI features about the annular ligament injuries in pediatric patients. Methods The appearance of MRI about annular ligament injuries in 15 pediatric patients diagnosed clinically were retrospectively analyzed. All patients (aged 4 years 8 months to 12 years 11 months) were scanned by MRI in 2-4 days after injury. Patients were divided into three groups according to the annular ligament injuries severity, which were simple annular ligament injuries, annular ligament injuries combined dislocation, annular ligament ruptures combined dislocation. Results Simple annular ligament injuries were showed in 2 cases, which appeared high signal but continuous configuration. Annular ligament injuries combined dislocation were showed 9 cases. Bald head sign, thickening and continuous ligment were found on axial image, together with compression of the radial joint space on sagittal and coronal view. Annular ligament ruptures combined dislocation were showed in 4 cases. The ligment showed"bald head sign", tortuosity and uneven thickening on axial view and compression of the radial joint space on sagittal and coronal view. Combining with the other tissue injuries were detected in 15 cases. Conclusion The annular ligament injuries show some MRI characteristics. Bald head sign is specific in the annular ligament injuries of pediatric patients.

Objective To explore the MRI features about the annular ligament injuries in pediatric patients. Methods The appearance of MRI about annular ligament injuries in 15 pediatric patients diagnosed clinically were retrospectively analyzed. All patients (aged 4 years 8 months to 12 years 11 months) were scanned by MRI in 2-4 days after injury. Patients were divided into three groups according to the annular ligament injuries severity, which were simple annular ligament injuries, annular ligament injuries combined dislocation, annular ligament ruptures combined dislocation. Results Simple annular ligament injuries were showed in 2 cases, which appeared high signal but continuous configuration. Annular ligament injuries combined dislocation were showed 9 cases. Bald head sign, thickening and continuous ligment were found on axial image, together with compression of the radial joint space on sagittal and coronal view. Annular ligament ruptures combined dislocation were showed in 4 cases. The ligment showed"bald head sign", tortuosity and uneven thickening on axial view and compression of the radial joint space on sagittal and coronal view. Combining with the other tissue injuries were detected in 15 cases. Conclusion The annular ligament injuries show some MRI characteristics. Bald head sign is specific in the annular ligament injuries of pediatric patients.