MRI Unit, Radiology Department, HT Medica, Jaén, Spain.
Division of Neuroradiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
Eur J Radiol. 2021 Oct;143:109900. doi: 10.1016/j.ejrad.2021.109900. Epub 2021 Aug 8.
Evaluation of Central Nervous System (CNS) focal lesions has been classically made focusing on the assessment solid or enhancing component. However, the assessment of solitary peripherally enhancing lesions where the differential diagnosis includes High-Grade Gliomas (HGG) and metastasis, is usually challenging. Several studies have tried to address the characteristics of peritumoral non-enhancing areas, for better characterization of these lesions. Peritumoral hyperintense T2/FLAIR signal abnormality predominantly contains infiltrating tumor cells in HGG whereas CNS metastasis induce pure vasogenic edema. In addition, the accurate determination of the real extension of HGG is critical for treatment selection and outcome. Conventional MRI sequences are limited in distinguishing infiltrating neoplasm from vasogenic edema. Advanced MRI sequences like Diffusion Weighted Imaging (DWI), Diffusion Tensor Imaging (DTI), Perfusion Weighted Imaging (PWI) and MR spectroscopy (MRS) have all been utilized for this aim with acceptable results. Other advanced MRI approaches, less explored for this task such as Arterial Spin Labelling (ASL), Diffusion Kurtosis Imaging (DKI), T2 relaxometry or Amide Proton Transfer (APT) are also showning promising results in this scenario. In this article, we will discuss the physiopathological basis of peritumoral T2/FLAIR signal abnormality and review potential applications of advanced MRI sequences for its evaluation.
中枢神经系统（CNS）局灶性病变的评估一直集中在评估实体或增强成分上。然而，对于孤立性周边增强病变的评估，鉴别诊断包括高级别胶质瘤（HGG）和转移瘤，通常具有挑战性。已经有几项研究试图确定瘤周非增强区域的特征，以更好地对这些病变进行特征描述。HGG 中的瘤周 T2/FLAIR 信号异常高信号主要包含浸润性肿瘤细胞，而 CNS 转移瘤则引起纯血管源性水肿。此外，准确确定 HGG 的实际扩展范围对于治疗选择和预后至关重要。常规 MRI 序列在区分浸润性肿瘤和血管源性水肿方面存在局限性。扩散加权成像（DWI）、扩散张量成像（DTI）、灌注加权成像（PWI）和磁共振波谱（MRS）等先进 MRI 序列已被用于实现这一目标，结果令人满意。其他用于此任务的较少探索的先进 MRI 方法，如动脉自旋标记（ASL）、扩散峰度成像（DKI）、T2 弛豫率或酰胺质子转移（APT），在这种情况下也显示出有希望的结果。在本文中，我们将讨论瘤周 T2/FLAIR 信号异常的病理生理基础，并回顾先进 MRI 序列在其评估中的潜在应用。
