熊猫放射授权发送 译者：花人青老师 一个喜欢音乐和摄影的快乐医生 History: A 67-year-old man presents with sudden-onset hemiplegia and is brought to the emergency room within 30 minutes of onset. Patient has a historyof atrial fibrillation. 病史：67岁男性，突发偏瘫，30分钟内被送至急诊室，患者有房颤病史。 Unenhanced CT images and CT angiography (CTA) of the brain are shown below. 颅脑CT平扫及CTA如下所示。 Conventional angiography was performed. Digital subtraction angiography (DSA) images are shown below. 行血管造影，DSA图像如下所示。 Thombectomy was performed. 行血栓切除术。 Findings 表现 Unenhanced head CT: CT demonstrates poor gray-white differentiation in the right basal ganglia and insular cortex. There is also focal high density in the M1 branch of the right MCA, which may represent acute thrombus. 颅脑CT平扫：右侧基底节及岛叶皮层灰白质分界模糊，右侧大脑中动脉M1段呈局限性高密度，可能代表急性血栓形成。 Head CTA: CTA demonstrates a filling defect at the proximal M1 branch of the right MCA with poor visualization of the distal vasculature. 颅脑CTA：右侧大脑中动脉M1段近段见充盈缺损，其远端血管分支显示较差。 Cerebral DSA and mechanical thrombectomy: There is a filling defect at the proximal M1 branch of the right MCA without distal perfusion. Following mechanical thrombectomy with a stent retriever ('stentriever') device, there is complete perfusion to the distal vasculature, TICI score of 3. 脑DSA及机械血栓清除术：右侧大脑中动脉M1段近段见充盈缺损，远段无灌注。使用支架取栓器行机械血栓清除后，远段血管灌注完全，脑梗死溶栓TICI评分为3。 Differential diagnosis：
鉴别诊断：
Diagnosis: Acute right middle cerebral artery embolic infarct. 诊断：右侧大脑中动脉急性栓塞性梗死 Key points Acute middle cerebral artery (MCA) infarct Pathophysiology 病理生理学 Acute occlusion of the middle cerebral artery, most commonly due to embolic occlusion, resulting in ischemia and infarction of the supplied vascular bed. Other causes include arterial dissection, thrombosis of ruptured atherosclerotic plaque or infection, and vasculitis. 大脑中动脉急性栓塞最常见的原因是栓子堵塞，导致其所供应区域缺血、梗死。其它原因包括：动脉夹层，动脉粥样硬化斑块破裂或炎症形成血栓，血管炎。 Demographics 人口统计特征 Most common in the elderly. 通常见于老年人。 Equal incidence in men and women. 男女发病率相同。 Increased incidence of embolic occlusion in atrial fibrillation. 房颤患者栓子阻塞的发病率较高。 Imaging 影像 Unenhanced CT: May demonstrate mass effect with sulcal effacement and/or midline shift, blurring of the gray-white junction, hyperdense MCA sign demonstrating acute thrombus in the vessel, or relatively hypodense parenchyma. CT平扫：表现一定的占位效应，脑沟消失、中线结构移位、灰白质分界模糊、大脑中动脉高密度征（血管内急性血栓）、脑实质密度相对减低。 CTA: Abrupt occlusion is seen with absent or minimal enhancement of the distal vasculature. CTA：血管突然闭塞，其远端分支缺如或少量强化显影。 Conventional angiography: Similar findings to CTA with abrupt occlusion and possible minimal flow around the occlusion. 血管造影：与CTA表现相同，血管突然闭塞，其周围血流减少。 MRI: Restricted diffusion seen in the territory of the MCA demonstrated as bright signal on DWI and dark signal on ADC mapping. Findings of mass effect such as sulcal effacement and midline shift may be present. Fluid-sensitive imaging, such as FLAIR, may show hyperintensity. Susceptibility-weighted imaging, such as gradient-recalled echo (GRE), is important to evaluate for blood products. MRI：大脑中动脉供血区弥散受限，表现为DWI高信号，ADC图低信号。可见一定的占位效应，例如脑沟消失、中线移位。水敏感成像FLAIR上，缺血区域呈高信号，磁敏感加权成像GRE序列对于评估有无出血十分重要。 补充知识 大脑中动脉（MCA）是颈内动脉两个终支中较大的血管，缺血及梗塞最常累及此区。MCA在解剖上一般分成4段或5段，M1=水平段，M2 =脑岛段，M3=岛盖段，M4、M5合称为终末段或皮层支。
1=颈内动脉 2=大脑前动脉 3=Heubner返动脉 4=颞前动脉 5=外侧豆纹动脉 6=大脑中动脉分叉处 7=大脑中动脉膝部 8=侧裂顶部（环状沟上限） M1段：自颈内动脉分叉部起点延伸至侧裂，可以看出它包含两部分，分叉前段及分叉后段。分叉前段是单独的主干，分叉后段则可能是单干，双干、三干甚至更多。 大脑中动脉高密度征（hyperdense middle cerebral artery sign, HMCAS）的确定标准：
|
|
|
