Abstract TP343: Low Density Sign in Intracerebral Hemorrhage: A Novel Predictor for Hematoma Expansion

Abstract

Background: Hematoma expansion in intracerebral haemorrhage (ICH) patients is a major determinant of early deterioration and associated with poor outcomes. Early identification of hematoma expansion with noncontrast computed tomography (NCCT) is very beneficial. We newly identified a NCCT sign called low density sign. Our study was to investigate whether low density sign was applicable for hematoma expansion prediction. Methods: Patients with spontaneous ICH enrolled in Huashan Hospital, Fudan University who underwent baseline NCCT scan within 6 h after ICH onset and the follow-up NCCT scan within 24 h after initial CT scan were included. Hematoma expansion was defined as absolute growth greater than 6 mL or a relative growth of more than 33%. The low density sign was defined as: (1) The hypoattenuation area that easily recognized by the naked eye has an identifiable border and most of the area within the hematoma. (2) The hypoattenuation area may vary in shape and connect or not with the adjacent brain tissue. (3) The minimal density the hypoattenuation area should be ≤27 Hounsfeld units (HU). For investigating the relationship between the presence of low density sign and hematoma expansion, univariate and multivariable logistic regression analyses were performed. Results: A total of 236 patients were included in the current study, 26.7% of which were observed hematoma expansion. Low density sign was found in 49 (20.8%) of the study population which was more common in patients with hematoma expansion (58.7%) than those without hematoma expansion (6.9%, P<0.001). Univariate and multivariable logistic regression analyses revealed Low density sign was an independent predictor for hematoma expansion (P=0.01, 95% CI: 3.25-114.05). The sensitivity, specificity and accuracy of low density sign for predicting hematoma expansion were 58.7%, 93.1% and 83.9% respectively, which were higher than previously reported NCCT signs: blend sign and black hole sign except the specificity of black hole sign (P<0.05). Conclusion: Our findings indicate low density sign as an easily identified NCCT sign may be an appropriate candidate for predicting hematoma expansion in patients with ICH.