A comparative study of the blend sign and the black hole sign on CT as a predictor of hematoma expansion in spontaneous intracerebral hemorrhage.

Hematoma expansion (HE) is a major determinant of a poor outcome in patients with a spontaneous intracerebral hemorrhage (sICH). The blend sign and the black hole sign are distinguished from non-contrast CT (NCCT) in patients with sICH, and both are independent neuroimaging predictors of HE. The purpose of the current study was to compare the value of the two signs in the prediction of HE. We retrospectively analyzed clinical and neuroimaging data from 228 patients with sICH who were treated at our hospital between August 2015 and September 2017. NCCT of the brain was performed upon admission (within 6 h of the onset of symptoms) to identify the blend sign and the black hole sign. HE was determined based on CT during a follow-up 24 h later. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with which the blend sign and the black hole sign predicted HE were calculated. Receiver operating characteristic (ROC) curve analysis was performed in order to compare the accuracy of the two signs in predicting HE. The blend sign was identified in 46 patients (20.2%) and the black hole sign was identified in 38 (16.7%) based on NCCT of the brain upon admission. Of the 65 patients with HE, the blend sign was noted in 28 and the black hole sign was noted in 22. The blend sign had a sensitivity of predicting HE of 43.1%, a specificity of 89.0%, a PPV of 60.9%, and an NPV of 79.7%. In contrast, the black hole sign had a sensitivity of predicting HE of 33.9%, a specificity of 90.2%, a PPV of 57.9%, and an NPV of 77.4%. The area under the ROC curve was 0.660 for the blend sign and 0.620 for the black hole sign (p = 0.516). In conclusion, the blend sign and the black hole sign on CT are both good predictors of HE in patients with sICH, though the blend sign seems to have a higher level of accuracy.