Vikas Pandey, MD
Li Q, Zhang G, Huang YJ, Dong MX, Lv FJ, Wei X, et al. Blend Sign on Computed Tomography: Novel and Reliable Predictor for Early Hematoma Growth in Patients with Intracerebral Hemorrhage. Stroke. 2015
Intracerebral hemorrhage is a medical issue with numerous complications. In the majority of cases, the hematoma that is found on imaging is treated as an unpredictable mass of hemorrhage that clinicians usually take a “wait-and-see” approach in management with vague blood pressure goals and automatic follow up imaging. The group of authors from China decided to try to take some of the guesswork out of intracerebral hemorrhage management by coming up with a radiologic sign that may have some utility in prediction of hematoma expansion, dubbed the “blend sign”.
The blend sign refers to an area on a CT brain scan within a cerebral hematoma that shows blending of a hypoattenuating and a hyperattenuating region with a well-defined margin in between the two areas (please refer to image A on the attached image figure). The thought process between why the blend sign may be a predictive factor for hematoma growth is that blood clots within the hematoma and becomes hyperattenuating whereas hypoattenuating blood may be a sign of more liquid blood signifying active bleeding. The data the group compiled included a total of 172 patients of which the blend sign was seen in 16.9% (29 of 172). Out of the 61 patients that ended up having hematoma growth, 24 (39.3%) had a blend sign on the admission CT. The interobserver agreement showed a K-value of 0.957. The sensitivity, specificity, positive and negative predictive values of the blend sign were 39.3%, 95.5%, 82.7%, and 74.1%, respectively.
The blend sign shows promise as a reliable, easy to use and highly specific marker for hematoma growth. As neurologists and radiologists clamor to find the best markers for predicting hematoma growth (blend sign, spot sign, swirl sign, etc), the end-goal is always to prevent deterioration in the patient’s condition and any additional factor that can aid this should be embraced during the hospital care process for these patients.