三维高分辨MR成像诊断及随访颅外段颈内动脉夹层四例

目的探讨颅外段颈内动脉夹层（ICAD）的特点及二三维高分辨MR成像（3DHR—MRI）在诊断及随访中的应用价值。方法4例临床或其他影像学初步诊断为颅外段ICAD患者，经3DHR．MRI检查明确诊断，给予抗凝或抗血小板聚集治疗4～9个月，随访其临床表现，采用美国国立卫生研究院卒中量表（NIHSS）进行临床预后评估，并复查3DHR—MRI观察病变血管壁内血肿变化的情况。结果①4例患者均接受3DHR—MRI检查，各序列轴位均可见“双腔征”及强度较均匀、稍高信号半月形壁内血肿；②4例患者临床预后均较好；③4例患者中，3例ICAD后动脉狭窄的患者，复查其血管壁内血肿均明显缩小；甚至完全消失；1例ICAD后真腔内血栓形成致动脉闭塞的患者，复查时闭塞远段部分再通。结论3DHR—MRI能够很好地进行颅外段ICAD的诊断及随访。及时诊治颅外段ICAD预后可能较好。

High-resolution MR imaging for diagnosis and follow-up study in 4 patients with extracranial internal carotid artery dissection

Objective To investigate the characteristics of extraeranial internal carotid artery dissec- tion （ICAD） and the application value of high-resolution MR imaging （HR-MRI） in the diagnosis and follow-up study. Methods Four patients with extraeranial ICAD were diagnosed by clinical and imaging and confirmed by 3D-HR-MRI. They received anticoagulant or antiplatelet therapies for 2 to 9 months and their clinical manifestations were followed up. Their prognostic evaluation was conducted using the National Institutes of Health Stroke Scale （NIHSS） , and reexamined with 3D-HR-MRI for observing the changes of hematoma in the vascular walls. Results ①All the 4 patients was detected by 3D-HR-MRI. The ＂double-lumen sign＂ and the ＂half-moon＂ shaped intramural hematoma with uniform strength and slightly higher signal could be seen on each axial sequence. ②The clinical prognosis of the 4 patients were good. ③The intramural hematomas were reexamined in 3 patients, their hematomas were significantly reduced or com- pletely disappeared. One patient with true lumen thrombosis caused arterial occlusion had distal recanalization during the reexamination. Conclusion HR-MRI may conducts the diagnosis and follow-up study of the extraeranial ICAD. The prognosis of the extracranial ICAD may be good if it is diagnosed and treated promptly.