Purpose or Case Report: Peritonsillar abscess (PTA) is a common and potentially life-threatening infection in the pediatric population. Contrast enhanced computed tomography (CE-CT) has traditionally been used to assist in diagnosis of PTA. However, factors such as radiation exposure, contrast administration and cost have led to increasing interest in the use of ultrasonography for PTA evaluation. The objective of this study was to evaluate the agreement between ultrasound and CE-CT in diagnosing PTA.
Methods & Materials: Pediatric patients sent for CE-CT of the neck for concern of PTA were prospectively enrolled in the study, and transcervical ultrasound of the neck was performed following CT. Two blinded pediatric radiologists independently assessed the ultrasound images for PTA or tonsillitis, and their findings were compared to CT results.
Results: A total of 21 patients were included in the study. When findings were dichotomized as abscess or no abscess, there was 100% concordance between ultrasound and CE-CT for both the left and right tonsils. When findings were categorized as normal, tonsillitis or abscess, there was very good agreement between ultrasound and CE-CT (Kappa coefficient of 0.87).
Conclusions: This study is the first to show transcervical ultrasound produces equivalent diagnostic results as CE-CT in the detection of tonsillar/peritonsillar abscess in the pediatric population. Ultrasound is also comparable to CE-CT in distinguishing among normal tonsils, tonsillitis and abscess. Given its safety, portability, and lack of need for intravenous access, ultrasound may be useful for first-line imaging of patients with suspected PTA.