1、SAH影像相關問題劉彬1、When a patient presents with asudden-onset headache, is CT an appropriate investigation?2、Is MRI useful if a CT is negative?Subarachnoid hemorrhage in ten questions 頭顱CTCT是SAH診斷的首選。但隨發(fā)病時間延長，CT敏感度逐漸下降。中國蛛網(wǎng)膜下腔出血診治指南2015腰穿當CT 結(jié)果陰性時，腰椎穿刺檢查有助于進一步提供診斷信息（級推薦，B 級證據(jù)）。中國蛛網(wǎng)膜下腔出血診治指南2015如何患者拒絕行腰穿檢查

2、或有腰穿禁忌怎么辦？MRI隨時間變化特點Temporo-occipital SAH. In transversal CT (A, arrows) and SWI (B, arrows) a temporal-occipital SAH cannot be definitively diagnosed, whereas in the coronal FLAIRsequence, the temporal-occipital SAH is clearly visible (C, arrows)If the clinical index of suspicion for an SAH is high

3、 when a CT is negative, it is recommended that:a CT angiogram of the circle of Willis be performed in order to investigate for an intracranial aneurysm;a LP be performed;a MRI may be indicated.Subarachnoid hemorrhage in ten questions Neurological signs IIIrd cranial nerve palsy Subarachnoid hemorrha

4、ge in ten questions Neurological signs features of pyramidal irritation and paralysis of the VIth cranial nerve are of no localizing value.Radiological signs associated with blood distributionThe distribution of the SAH and presence of any hematoma help localize the aneurysm responsible for the blee

5、ding.An SAH predominantly in the anterior part of the interhemispheric cisterna and the suprasellar cisternae and/or an interhemispheric hematoma suggest an anterior communicating artery aneurysm. Radiological signs associated with blood distributionAn SAH predominantly in the motor cortex sulcus or

6、 a temporopolar hematoma should trigger investigation for an ipsilateral middle cerebral artery aneurysm. Radiological signs associated with blood distributionAn isolated lenticular hematoma may occur as a result of rupture of an end carotid aneurysm. Radiological signs associated with blood distributionAn acute subdural hematoma without a background of injury should trigger investigation for a posterior carotid aneurysm.Radiological signs associated with blood distributionAn SAH predominantly in the basal cisternae next to the cerebellopontine angle cister