Wardlaw J M, Armitage P, Dennis M S, Lewis S, Marshall I, Sellar R
Department of Clinical Neurosciences, Medical Physics, Western General Hospital NHS Trust, Edinburgh, UK.
J Stroke Cerebrovasc Dis. 2000 Mar-Apr;9(2):70-5. doi: 10.1053/jscd.2000.0090070.
Diffusion-weighted magnetic resonance imaging (DWI) shows cerebral infarction within minutes of its occurrence, but its value in clinical management after the stroke is less clear. We evaluated DWI scans in patients with minor strokes to determine whether DWI was helpful in identifying the stroke lesion and how long after the stroke could DWI still identify the lesion.
Patients admitted to our hospital with symptoms of a lacunar or minor cortical or posterior fossa stroke underwent T2 and proton density magnetic resonance imaging (MRI) of the brain, followed by DWI on a 1.5 Tesla Siemens scanner. The individual MR sequence images were examined (blind to each other and clinical information) to identify any recent infarction.
In 40 subjects (13 lacunes, 17 cortical, 5 posterior circulation infarctions, 2 transient ischemic attacks [TIAs] and 3 non-stroke), DWI scans showed the recent infarction clearly (even tiny ones) in 24 subjects (60%), in 12 of whom no infarction was visible on the T2 or proton density images. DWI also correctly excluded infarction in patients subsequently found not to have had a stroke. The diffusion abnormality was visible for up to 23 days after the stroke.
DWI is useful for pinpointing the site of small infarctions that are either not visible or not distinguishable from previous lesions on T2 or proton density MRI, up to at least 3 weeks after the stroke. This may assist with planning further management of the stroke. The clinical use of DWI should not be restricted to just the first few hours after the stroke.
扩散加权磁共振成像（DWI）在脑梗死发生数分钟内即可显示病变，但在卒中后的临床管理中的价值尚不清楚。我们评估了轻度卒中患者的DWI扫描，以确定DWI是否有助于识别卒中病变，以及卒中后DWI能在多长时间内仍可识别病变。
因腔隙性、轻度皮质或后颅窝卒中症状入院的患者接受脑部T2加权成像和质子密度磁共振成像（MRI）检查，随后在1.5特斯拉西门子扫描仪上进行DWI检查。对各个磁共振序列图像进行检查（彼此之间以及临床信息均不知情），以识别任何近期梗死灶。
在40名受试者（13例腔隙性梗死、17例皮质梗死、5例后循环梗死、2例短暂性脑缺血发作[TIAs]和3例非卒中患者）中，DWI扫描在24名受试者（60%）中清晰显示了近期梗死灶（即使是微小梗死灶），其中12名受试者的T2加权或质子密度图像上未见梗死灶。DWI还正确排除了后来被发现未发生卒中的患者的梗死灶。扩散异常在卒中后长达23天可见。
DWI有助于确定在T2加权或质子密度MRI上不可见或与既往病变难以区分的小梗死灶的部位，至少在卒中后3周内如此。这可能有助于规划卒中的进一步管理。DWI的临床应用不应仅限于卒中后的最初几个小时。
