糖尿病（DM）是缺血性脑血管病（ICD）的重要危险因素之一。缺血性脑血管病早期可无明显的临床症状及体征，即无症状性脑缺血，随着病情的加重而出现暂短性脑缺血，严重者可出现致残或致命的脑梗塞。为了早期防治本病，了解糖尿病患者无症状性脑缺血发生的情况，我们采用了经颅 Diabetes mellitus (DM) is one of the important risk factors for ischemic cerebrovascular disease (ICD). Early ischemic cerebrovascular disease may be no obvious clinical symptoms and signs, that is, asymptomatic cerebral ischemia, with the progression of the disease appears transient cerebral ischemia, severe cases may be disabled or fatal cerebral infarction. In order to prevent this disease early, to understand the situation of asymptomatic cerebral ischemia in diabetic patients, we used the transcranial