BACKGROUND AND OBJECTIVES:Diagnostic features of peritonsillar abscess are an asymmetrically enlarged palatine tonsil with peripheral rim enhancement and central low density in the post-contrast computed tomography (CT). Although it is necessary to differentiate tumorous conditions of tonsils to compare pre- and post-contrast CT, pre-contrast CT may be less useful in the diagnosis of peritonsillar abscess. This study aims to evaluate of the efficacy of single post-contrast CT for diagnosis and treatment of peritonsillar abscess.SUBJECTS AND METHOD: We retrospectively compared 29 patients with peritonsillar abscess, who were diagnosed by single post-contrast CT, with 36 patients diagnosed by pre- and post-contrast CT to determine the success rates of pus drainage and hospital days. Additionally, two otorhinolaryngologists made a judgment of abscess presence for sixty randomly mixed CT images of peritonsillar abscess or tonsillitis with pre- and post-contrast CT or single post-contrast CT.

RESULTS:There were no significant differences in the success rate of drainage (p=0.622) and hospital days (p=0.504) between groups with/without pre-contrast CT. Abscess presence was judged by raters with/without pre-contrast CT. Inter-rater agreement value (Cohen's kappa) was 0.825 (p<0.01).

CONCLUSION:Single post-contrast CT of peritonsillar abscess may be a good alternative for diagnosis and treatment and may reduce unnecessary exposure to radiation.