Emergency Department, The First Affiliated Hospital of Guizhou Medical University, Guiyang, 550004, China.
Department of Neurology, Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Neurocrit Care. 2021 Oct;35(2):367-378. doi: 10.1007/s12028-020-01165-1. Epub 2021 Jan 6.
Blend sign on initial computed tomography (CT) is associated with poor outcome in patients with intracerebral hemorrhage (ICH). However, the mechanisms underlying the blend sign formation are poorly understood. The present study aimed to explore the possible mechanism of the CT blend sign in patients with ICH.
Seventy healthy rabbits were selected to prepare an ICH model. The animals were assigned to a whole blood group + whole blood group (ww group, 50 rabbits), a whole blood + plasma group (wp group, 10 rabbits) or a whole blood + serum group (ws group, 10 rabbits). The animals of the ww group were allocated to five subgroups based on the interval between the first infusion of blood and the second one. The subgroups included ww 1 h group (with an interval of 1 h), ww 2 h group, ww 3 h group, ww 4 h group and ww 5 h group. The rabbits from each group received first infusion of 0.3 mL of whole blood into the basal ganglia area to form a hematoma. Then, they received a second infusion of the same amount of whole blood, plasma or serum into the brain to form another hematoma adjacent to the first one.
A hematoma with two densities on brain CT could be formed in each group after a second infusion of blood into the brain. A significant difference in CT attenuation values was observed between the hyperattenuation and the hypoattenuation in all the groups. However, only the morphological features of the hematoma in the ww group was in accordance with the CT blend sign observed in humans. The CT attenuation values in the hypodensity area of the ww 4 h group or the ww 5 h group were decreased compared with the ww 1 h group to the ww 3 h group.
The CT blend sign observed in humans might be composed of two parts of blood with different ages. The hypodense area might be blood with older age and the hyperdense area might be new bleeding.
在脑出血（ICH）患者中，初始计算机断层扫描（CT）上的“混合征”与不良预后相关。然而，“混合征”形成的机制尚不清楚。本研究旨在探讨 ICH 患者 CT 混合征的可能机制。
选取 70 只健康家兔制备 ICH 模型。动物分为全血+全血组（ww 组，50 只）、全血+血浆组（wp 组，10 只）和全血+血清组（ws 组，10 只）。ww 组的动物根据第一次输注血液和第二次输注血液之间的间隔分为五组。亚组包括 ww1h 组（间隔 1h）、ww2h 组、ww3h 组、ww4h 组和 ww5h 组。每组动物首先将 0.3mL 全血注入基底节区形成血肿。然后，它们接受第二次等量的全血、血浆或血清注入大脑，在第一个血肿旁形成另一个血肿。
每组动物在第二次脑内输注血液后均可在脑 CT 上形成两个密度的血肿。所有组的高衰减区与低衰减区之间的 CT 衰减值均存在显著差异。然而，只有 ww 组的血肿形态特征与人类观察到的 CT 混合征相符。ww4h 组或 ww5h 组的低衰减区 CT 衰减值与 ww1h 组至 ww3h 组相比降低。
人类观察到的 CT 混合征可能由两种不同年龄的血液组成。低衰减区可能是较陈旧的血液，高衰减区可能是新的出血。
