Purpose or Case Report: Ultrasound is a valuable and noninvasive tool for the evaluation of the nail unit. With the availability of high-frequency transducers, it is now possible to obtain detailed images of normal nail anatomy, including the dorsal and ventral plates, nail bed and matrix, periungual folds, and underlying structures such as the bony surface and extensor tendons. These technological advances have enabled imaging-based diagnosis of nail disorders that were previously dependent solely on clinical or histopathological assessment.
Objectives:
To describe the normal ultrasonographic anatomy of the nail unit through representative images and illustrative diagrams.
To present the main ultrasound findings of common inflammatory-infectious, traumatic, and tumoral pediatric nail disorders, with schematic drawings of the diseases.
To encourage the integration of key sonographic criteria into the daily practice of general radiologists for the evaluation of nail pathology.
Methods & Materials: We review the normal ultrasonographic components of the nail — including the dorsal and ventral plates, interplate space, nail root, nail bed, and periungual folds — illustrated with high-resolution images and schematic representations.
Representative cases demonstrate characteristic sonographic findings of frequent nail pathologies, such as:
Onychomadesis: separation of the nail plate from the matrix with distal detachment from the proximal fold.
Onychocryptosis (ingrown nail): penetration of the nail edge into the lateral skin fold.
Retronychia: proximal ingrowth of the nail into the overlying proximal fold.
Paronychia: inflammatory involvement of the periungual soft tissues.
Onychopapilloma: benign tumor arising from the nail bed or distal matrix, rare in children but may be seen in teenagers.
Glomus tumor: painful lesion derived from glomus bodies, located within the nail bed.
Subungual exostosis and osteochondroma: osteocartilaginous proliferation originating from the distal phalanx beneath the nail.
Congenital nail dystrophy: nail abnormalities present since birth or early childhood.
Post-traumatic subungual fibroma.
Results:
Conclusions: Recognizing the normal ultrasonographic anatomy of the nail apparatus and its pathological variations enhances the diagnostic accuracy of radiologists. Incorporating sonographic assessment into routine practice can significantly support clinical decision-making in nail disorders, especially within pediatric populations.