术中MR液体反转恢复序列在低级别神经胶质瘤切除术中的应用价值

目的探讨术中磁共振成像(intraoperative MRI,iMRI)中的液体反转恢复序列(fluid attenuated inversion recovery,FLAIR)在低级别神经胶质瘤(WHOⅠ~Ⅱ级)切除术中的应用价值,从而对是否存在残留肿瘤的诊断提供帮助。方法选取18例低级别神经胶质瘤(low-grade gliomas,LGGs)患者的术中MRI,查看FLAIR图像中手术腔周围是否存在高信号,并对术前或术后复查过MRI患者的图像进行分析,比较术区周边FLAIR信号的变化情况。结果低级别神经胶质瘤切除术中手术区域边缘iMRI的FLAIR表现:1)没有FLAIR异常信号7例;2)线状FLAIR高信号(linear FLAIR hyperintensity,LFH)7例;3)结节或片状FLAIR高信号(nodular or patchy FLAIR hyperintensity,NPFH)4例。接受iMRI分析的患者的手术切缘上无FLARI异常信号中的4例术后3个月复查MRI术区周围未见异常改变;出现LFH中有4例患者在术后3个月后复查MRI,异常信号强度减低或消失。而2例NPFH随即进行了第二次手术切除,并再次行术中MRI扫描,最终组织病理学为肿瘤残留,1例NPFH未进行二次手术,半年后复查,异常信号范围增大。结论经iMRI分析的手术区域切缘可能出现FLAIR高信号,出现线状FLAIR高信号时不应误认为是残余肿瘤,而出现结节或片状FLAIR高信号时可能是残余肿瘤。iMRI FLAIR在初步判断低级别神经胶质瘤切除术术区边缘是否存在残留肿瘤方面有一定的应用价值。

Application of fluid reversal recovery sequence of intraoperative magnetic resonance imaging in low grade glioma surgery

Objective To evaluate the utility on fluid attenuated inversion recovery(FLAIR)sequence of intraoperative magnetic resonance imaging(iMRI)in resection of low grade gliomas(WHOⅠ~Ⅱ),and to help to diagnose the existence of residual tumor.Methods iMRI findings and clinical data were analyzed retrospectively in 18 patients who underwent surgery for a low-grade glioma(LGGs)to search for whether there were FLAIR hyperintensity surrounding the surgical cavity.Preoperative or postoperative MRI images of patients were analyzed to compare the variation of FLAIR signals around the operative area.Results FLAIR manifestations of iMRI on the margins of the resected area of low-grade glioma:1)no FLAIR abnormality in 7 cases;2)7 cases with linear FLAIR hyperintensity(LFH);3)nodular or patchy FLAIR hyperintensity(NPFH)in 4 cases.No abnormal signal of FLARI was found on the surgical edge on follow-up MRI after 3 months in 4 cases.Linear FLAIR hyperintensities on the surgical margin in 4 patients reduced or vanished on follow-up MRI after 3 months.2 cases of NPFH underwent the second surgical resection,and the intraoperative MRI scan was performed again.The final pathological result was tumor residue.1 case of NPFH did not undergo the second surgery,and the review half a year later showed that the FLAIR hyperintensities range increased.Conclusion FLAIR hyperintensities may appear on the surgical margin of the patients analyzed with iMRI.The presence of linear FLAIR hyperintensities should not be mistaken for residual tumor,while the presence of nodules or patchy FLAIR hyperintensities may be residual tumor.IMRI FLAIR has a certain value in determining whether there is residual tumor on surgical margins of low-grade glioma resection.