Tonsil ultrasound: technical approach and spectrum of pediatric peritonsillar infections

Peritonsillar infections are one of the most common deep neck space infections, particularly in adolescents. Inaccurate diagnosis can lead to delay in management and potentially life-threatening complications. Contrast-enhanced computed tomography (CT) scan of the neck traditionally has been used to diagnose suspected peritonsillar abscess. With growing concern over radiation exposure, there has been increasing utilization of ultrasound (US) using intraoral and transcutaneous approaches. We chose the transcutaneous US technique due to its ease of performance in children. The purpose of this article is twofold: a) to describe our technique of performing transcutaneous US of the tonsil showing sonographic appearance of normal tonsil, highlighting pertinent anatomy and unique considerations for this modality in children, and b) to illustrate the sonographic findings in the spectrum of pediatric peritonsillar infections, which includes uncomplicated tonsillitis, peritonsillar cellulitis, small intratonsillar abscess and frank peritonsillar abscess. Parapharyngeal abscess can sometimes be detected.