低场强磁共振弥散成像在脑梗死诊断中的应用价值

目的 评价低场磁共振弥散序列对各期脑梗死的诊断作用。方法 应用磁共振T1W1，T2WI和水抑制反转恢复成像(T2 FLAIR)和DWI对70例各期脑梗死病人进行86人次MRI检查，并作ADC图，测定ADC值。结果在超急性脑梗死病例中，DWI和ADC图均表现缺血，但T2及T2FLAIR成像表现正常，病灶的ADC值随梗死时间延长，呈由低向高变化的趋势。结论低场磁共振DWI对急性期及超急性期脑缺血病变高度敏感，显示率及敏感性是100％．常规T2WI敏感性37％；ADC图可进一步量化缺血程度，二者结合应用对脑梗死的早期诊断和病灶的转归评估有重要意义。

The utility of low field intensity MRI using DWI sequence in the diagnosis of cerebral infarction

Objective To assess the utility of low field intensity MRI using diffuse weighted imaging(DWI) sequence in the diagnosis of cerebral infarction.Methods Seventy patients with cerebral infarction,who included 12 superactive stage,36 acute stage and 22 subacute stage underwent MRI examinntions with T1WI,T2WI ,T2 FLAIR and DWI sequence and obtained the depiction of ADC figure and the measurement of ADC value.Results Among the patients with superacute stage of cerebral infarction,DWI and ADC figure presented as ischemia but T2WI and T2 FLIAR imaging presented as normality,with prolongation of infarction time,ADC value in the lesions showed the changed tendency from low to high.Conclusion Low field intensity DWI has high sensitivity in the diagnosis of acute and superacute stage of cerebral infarction,the visualization rate and sensitivity achieve to 100 %wereas the sensitivity of conventional T2WI is only 37 %.ADC figure can more accurately quantify the ischemic degree.The integration of DWI and ADC figure has very important value for diagnosing the early cerebral infarction and evaluating the conversion of the lesions.