Satellite effusion sign: an important CT sign of epidural hematoma / 中华神经医学杂志

ABSTRACT

Objective:To investigate the CT imaging features of epidural hematoma (EDH) surrounding subdural effusion (satellite effusion sign) and its application value in diagnosis of EDH.Methods:A retrospective analysis of clinical and imaging data of 30 patients with EDH and 122 patients with acute subdural hematoma (SDH), admitted to our hospitals from December 2017 to February 2020, was performed. The frequencies of satellite effusion sign were compared in the two groups, and the differences between the correct diagnosis rate of traditional CT performance and the correct diagnosis rate of traditional CT performance+satellite effusion sign were compared in the two groups; the specific characteristics of satellite effusion sign was clarified and its relations with morphological characteristics and distribution of hematoma were analyzed.Results:Among 30 patients with acute EDH, the occurrence rate of satellite effusion sign was 63.3% (19/30); among 122 patients with acute SDH, the occurrence rate of satellite effusion sign was 2.5% (3/122); the difference was statistically significant ( χ2=67.248, P=0.000). Among the 30 patients with acute EDH, the correct diagnosis rate of traditional CT manifestation was 86.7% (26/30), and the correct diagnosis rate of traditional CT manifestation+satellite effusion sign was 93.3% (28/30), without statistically significance ( χ2=0.185, P=0.667). The length of the satellite effusion sign was (1.1±0.9) cm, ranged from 0.2 cm-3.1 cm; the width was (3.6±2.0) mm, ranged from 1.4 mm-7.5 mm. The incidence of satellite effusion sign in the frontotemporal EDH patients (73.9%) was significantly increased as compared with that in the occipitoparietal EDH patients (28.6%, P<0.05); that of patients with clinically diagnosed cerebral contusion, laceration, cerebral hernia or other severe to extremely severe craniocerebral injuries (22.2%) was significantly reduced as compared with that of patients with mild to moderate craniocerebral injuries (81.0%, P<0.05). Conclusion:Satellite effusion sign is an important new CT sign in the diagnosis of EDH, which is closely related to the locations of hematoma and severities of craniocerebral injury.