Kadimi S, Terry J B, Gomez C R
Comprehensive Stroke Center, University of Alabama, Birmingham, Alabama, USA.
J Neuroimaging. 2000 Oct;10(4):228-30. doi: 10.1111/jon2000104228.
The authors describe the appearance of acute thromboembolic occlusion of the middle cerebral artery (MCA) using transcranial duplex ultrasonography. Acute occlusion of the MCA commonly leads to severe cerebral infarction. In patients with acute MCA occlusion, secondary edema and elevated intracranial pressure are major causes of increased morbidity and mortality. Thus, the prompt detection of occlusion influences early therapy, including thrombolysis and increased control of intracranial pressure. The hyperdense appearance of the acutely occluded MCA as seen using computed tomography (CT) has been extensively reported in the literature. However, its appearance using transcranial duplex ultrasonography has not been reported. The authors report four patients who had clinical features of ischemia throughout the MCA territory. All patients were studied with CT and transcranial duplex ultrasonography within 6 hours of the onset of symptoms. Head CT of all four patients showed a hyperdense MCA sign with infarction of the MCA territory. Transcranial duplex studies using either pulsed Doppler or color Doppler sonography displayed a hyperechoic MCA with no evidence of flow. Subsequent duplex ultrasonography and magnetic resonance angiography showed all four patients had ipsilateral occlusion of the internal carotid artery. Transcranial duplex ultrasonography assists in the early diagnosis of acute MCA occlusion. The affected vessel is displayed as a hyperechoic structure associated with no flow using Doppler examination.
作者使用经颅双功超声描述大脑中动脉（MCA）急性血栓栓塞性闭塞的表现。MCA急性闭塞通常会导致严重的脑梗死。在急性MCA闭塞患者中，继发性水肿和颅内压升高是发病率和死亡率增加的主要原因。因此，闭塞的快速检测会影响早期治疗，包括溶栓和加强颅内压控制。计算机断层扫描（CT）显示的急性闭塞MCA的高密度表现已在文献中广泛报道。然而，其经颅双功超声表现尚未见报道。作者报告了4例具有整个MCA区域缺血临床特征的患者。所有患者在症状发作6小时内均接受了CT和经颅双功超声检查。所有4例患者的头部CT均显示MCA高密度征伴MCA区域梗死。使用脉冲多普勒或彩色多普勒超声进行的经颅双功研究显示MCA呈高回声，无血流迹象。随后的双功超声和磁共振血管造影显示所有4例患者均有同侧颈内动脉闭塞。经颅双功超声有助于急性MCA闭塞的早期诊断。使用多普勒检查时，受累血管显示为无血流的高回声结构。
