OBJECTIVE: To describe a novel radiographic sign ("halo") and a new classification method of an evolving perisigmoid @entity7181 and present its correlation with intraoperative findings. STUDY DESIGN: Retrospective and prospective cohort study in a tertiary academic @entity1 's hospital. METHODS: The retrospective arm (15 @entity1 ) was conducted between 1998 and 2007 and the prospective arm (11 @entity1 ) between 2008 and 2013. The computerized tomographic appearance of the perisigmoid region was classified into four groups: Class I, normal; Class II, smooth halo; Class III, nodular halo 4 mm or less in diameter; and Class IV, gross nodular halo more than 4 mm in diameter. Intraoperative findings of the perisigmoid region were compared with the preoperative scan results. RESULTS: The correlation between preoperative imaging and intraoperative findings of the retrospective arm was highly significant (p = 0.007). The correlation between the preoperative imaging studies and intraoperative findings of the prospective arm was also highly significant (p = 0.005). The interobserver agreement for the proposed classification method was high (Cohen kappa score, 0.76; weighted kappa score, 0.84). CONCLUSION: A novel radiographic sign ("halo") and a new classification method for an evolving perisigmoid @entity7181 in acute @entity2267 are described. A thin and smooth halo sign is not indicative of a true @entity733 formation. Gross perisigmoid granular changes, however, are highly suggestive of an @entity7181 that warrants surgical intervention.

A Novel Radiographic Sign and a New Classifying System in XXXX .

@entity1 :: ('9606', 'Species') :: ['children'] @entity7181 :: ('MESH:D020802', 'Disease') :: ['epidural abscess'] @entity733 :: ('MESH:D000038', 'Disease') :: ['abscess'] @entity2267 :: ('MESH:D008417', 'Disease') :: ['mastoiditis']
@entity7181 :: (MESH:D020802,Disease) :: ['Mastoiditis-Related Epidural Abscess']
