脑梗死患者磁共振弥散加权成像ADC值演变的临床研究

A clinical study of the development of apparent diffusion coefficient on diffusion weighted MRI in patients with cerebral infarction

目的通过观察脑梗死患者磁共振弥散加权成像ADC值的变化，探讨脑梗死不同时期ADC值相对应的脑水肿的变化规律。方法选取本院2013年1月至2014年8月收治的脑梗死并行磁共振DWI检查的病例269例，采集脑梗死后超早期（≤6h）、急性期（6～24h）、坏死期（24．48h）、软化期（48h～3w）ADC值变化，并将脑梗死患者按前后循环、灰白质观察及分析各组ADC值的差别。结果脑梗死急性期DWI图像均为高信号，而ADC图为低信号。超早期病灶侧ADC均值为（0．524±0．080），急性期为（0．401±0．081），坏死期为（0．369±0．084）[较急性期下降（P〈0．001）]，软化期为（0．524±0．100）[较坏死期上升（P〈0．001）]，ADC值由高到低再逐渐升高，呈“U”型变化。白质病灶侧ADC均值较灰质降低[（0．432±0．103）vs．（0．455±0．126），P〈0．05]；前循环病灶侧ADC均值较后循环降低[（0．431±0．117）vs．（0．479±0．095），P〈0．01]。结论ADC值可用于预判脑梗死细胞水肿的类型，有助于指导临床治疗。

Objective To observe the changes of apparent diffusion coefficient （ADC） value on diffusion weighted imaging （DWI） after cerebral infarction, in order to identify the variation between ADC values and corresponding cerebral edema in different periods of cerebral infarction. Methods Retrospective study （2013.1- 2014.8） including 269 patients at hyperacute （ ≤ 6 h）, acute （6-24 h）, necrosis （24-48 h）, softening （48 h-3 w） stages of cerebral infarction were imaged with DWI. The average ADC value of the infracted lesion and contralateral normal brain were calculated respectively. And analyzed the difference of the ADC values between anterior circulation and posterior circulation, gray and white matter. Results All infracted lesions in hyperacute, acute, necrosis and softening stages showed hyperintense signal on DWI, while ADC value reduced at stroke onset. The average ADC value of hyperacute, acute, necrosis and softening stages were （0.524±0.080）, （0.401±0.081）, （0.369±0.084）, （0.524±0. 100）, which showed that the curve of ADC value in cerebral infarction was similar to Ushaped. The ADC value in grey matter was higher than that in white matter [（0.455±0.126） vs.（0.432±0.103）, P〈0.05], the average ADC value of anterior circulation infarction was lower than that of posterior circulation infarction [（0.431±0.117） vs.（0.479±0.095）, P〈0.01]. Conclusion ADC value can be used to estimate the type of cerebral edema, which is helpful to guide clinical treatment.