Soni Neetu, Srindharan Karthika, Kumar Sunil, Bhaisora Kamlesh Singh, Kalita Jayantee, Mehrotra Anant, Mishra Prabhakar
Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.
Neurol India. 2018 Nov-Dec;66(6):1667-1671. doi: 10.4103/0028-3886.246270.
To evaluate the role of diffusion tensor imaging (DTI) in the differentiation of neoplastic and non-neoplastic brain lesions, on the basis of DTI parameters, fractional anisotropy (FA) and mean diffusivity (MD) from the lesion (L) and the perilesional edema (PE).
Patients with newly diagnosed 25 neoplastic [10 high grade gliomas (HGG), 11 metastases, 4 low grade glioma (LGG)] and 25 non-neoplastic [13 tuberculomas and 12 neurocysticercosis (NCC)] brain lesions underwent an MRI, including the DTI sequences. Fractional anisotropy from the lesion (FAL) and mean diffusivity from the lesion (MDL), as well as fractional anisotropy from the perilesional edema (FAPE), and mean diffusivity from the perilesional edema (MDPE) were calculated and quantified using region of interest (ROI) based assessment on DTI derived FA and MD parametric maps. The mean values of FAL, FAPE, MDL and MDPE from the two groups were compared by the independent sample t-test.
In the non-neoplastic group, perilesional edema showed a significantly higher (P = 0.015) MD compared to the neoplastic group. Perilesional FA and lesional FA and MD showed no such statistically significant difference. On further subgroup analysis, MDPE was higher in metastases compared to HGG (P < 0.001), reflecting an increase in the vasogenic edema. Perilesional FA was higher in HGG compared to metastases and tuberculomas (P < 0.001) reflecting tumour infiltration in addition to vasogenic edema. FAL was higher in tuberculomas compared to metastases (P < 0.001), pointing to a more microstructural destruction in metastases.
Quantitative DTI parameters, FA and MD, from the lesion and from the area of perilesional edema are helpful in the evaluation and differentiation of brain lesions.
基于扩散张量成像（DTI）参数、病变（L）及病变周围水肿（PE）的分数各向异性（FA）和平均扩散率（MD），评估DTI在鉴别脑肿瘤性和非肿瘤性病变中的作用。
25例新诊断的脑肿瘤性病变[10例高级别胶质瘤（HGG）、11例转移瘤、4例低级别胶质瘤（LGG）]和25例非肿瘤性病变[13例结核瘤和12例神经囊尾蚴病（NCC）]患者接受了包括DTI序列在内的MRI检查。使用基于感兴趣区（ROI）的评估方法，在DTI衍生的FA和MD参数图上计算并量化病变的分数各向异性（FAL）、病变的平均扩散率（MDL）、病变周围水肿的分数各向异性（FAPE）以及病变周围水肿的平均扩散率（MDPE）。通过独立样本t检验比较两组的FAL、FAPE、MDL和MDPE平均值。
在非肿瘤性病变组中，病变周围水肿的MD显著高于肿瘤性病变组（P = 0.015）。病变周围FA、病变FA和MD无统计学显著差异。进一步的亚组分析显示，转移瘤的MDPE高于HGG（P < 0.001），反映血管源性水肿增加。HGG的病变周围FA高于转移瘤和结核瘤（P < 0.001），反映除血管源性水肿外还有肿瘤浸润。结核瘤的FAL高于转移瘤（P < 0.001），表明转移瘤的微观结构破坏更严重。
来自病变及病变周围水肿区域的定量DTI参数FA和MD有助于脑病变的评估和鉴别。
