Neurosonology Laboratory, Cerebrovascular Program, Neurology Service, Department of Internal Medicine, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Vitacura, Santiago, Chile.
Stroke. 2013 Apr;44(4):1169-71. doi: 10.1161/STROKEAHA.111.000527. Epub 2013 Feb 28.
The accuracy of diffusion-weighted imaging (DWI) for the diagnosis of acute cerebral ischemia among patients with suspected ischemic stroke arriving to an emergency room has not been studied in depth.
DWI was performed in 712 patients with acute or subacute focal symptoms that suggested an acute ischemic stroke (AIS), 609 of them with AIS.
DWI demonstrated a sensitivity of 90% and specificity of 97%, a positive likelihood ratio of 31 and a negative likelihood ratio of 0.1 for detecting AIS. The overall accuracy was 95%. Of those patients who demonstrated abnormal DWI studies, 99.5% were AIS patients, and of those patients with normal DWI studies 63% were stroke mimics.
DWI is accurate in detecting AIS in unselected patients with suspected AIS; a negative study should alert for nonischemic conditions.
在因疑似缺血性脑卒中而到急诊就诊的患者中，扩散加权成像（DWI）对急性脑缺血的诊断准确性尚未得到深入研究。
对 712 例具有急性或亚急性局灶性症状（提示急性缺血性脑卒中，AIS）的患者进行了 DWI 检查，其中 609 例为 AIS 患者。
DWI 检测 AIS 的灵敏度为 90%，特异度为 97%，阳性似然比为 31，阴性似然比为 0.1。总体准确率为 95%。在表现出异常 DWI 研究的患者中，99.5%为 AIS 患者，而在表现出正常 DWI 研究的患者中，63%为脑卒中模拟症患者。
DWI 可准确检测疑似 AIS 患者的 AIS；阴性研究应提示非缺血性疾病。
