Onishi Shumpei, Amatya Vishwa Jeet, Kolakshyapati Manish, Takano Motoki, Yonezawa Ushio, Taguchi Akira, Kaichi Yoko, Takeshima Yukio, Awai Kazuo, Sugiyama Kazuhiko, Kurisu Kaoru, Yamasaki Fumiyuki
Department of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Department of Neurosurgery, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Hiroshima, Japan.
Department of Pathology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Eur J Radiol. 2020 May;126:108924. doi: 10.1016/j.ejrad.2020.108924. Epub 2020 Mar 2.
T2-FLAIR mismatch sign was reported as specific imaging marker in non-enhancing diffuse astrocytoma, IDH-mutant & 1p/19q non-codeleted. However, most of the previous studies for T2-FLAIR mismatch sign were confirmed only among lower grade glioma. The aim of this study is to assess the T2-FLAIR mismatch sign in dysembryoplastic neuroepithelial tumor (DNET) and unveil the exception rules of the sign.
Eleven patients with histopathologically confirmed DNET were included in this study. The MR images were evaluated by 2 independent reviewers to assess (i) the presence or absence of T2-FLAIR mismatch sign and (ii) the presence or absence of gadolinium enhancement. CT was also performed to evaluate calcification and localized thinning of the skull bone. Inter-reviewer agreement with Cohen's kappa (κ) was calculated.
The T2-FLAIR mismatch sign was present in 8 cases (72.7 %) and absent in 3 cases (27.3 %). None of them showed contrast enhancement on initial MR images. The inter-reviewer agreement for T2-FLAIR mismatch and CT characteristics was excellent (κ = 1.00). All of the DNET without T2-FLAIR mismatch presented with calcification on CT. All of the DNET adjacent to skull vault (5 cases) presented with localized bone thinning overlying the tumor.
The T2-FLAIR mismatch sign was observed in more than half of the DNET and the sign is not specific for diffuse astrocytoma, IDH-mutant & 1p19q non-codeleted. The localized skull bone thinning overlying the tumor might help for diagnosis of DNET in some cases.
T2-FLAIR不匹配征被报道为非强化弥漫性星形细胞瘤（异柠檬酸脱氢酶（IDH）突变且1p/19q未缺失）的特异性影像学标志物。然而，之前大多数关于T2-FLAIR不匹配征的研究仅在低级别胶质瘤中得到证实。本研究的目的是评估胚胎发育不良性神经上皮肿瘤（DNET）中的T2-FLAIR不匹配征，并揭示该征象的例外规则。
本研究纳入11例经组织病理学确诊的DNET患者。由2名独立的阅片者对磁共振成像（MR）图像进行评估，以判断（i）T2-FLAIR不匹配征的有无，以及（ii）钆增强的有无。还进行了计算机断层扫描（CT）以评估钙化和颅骨局部变薄情况。计算阅片者间的一致性并采用Cohen's kappa（κ）系数。
8例（72.7%）出现T2-FLAIR不匹配征，3例（27.3%）未出现。所有患者在初始MR图像上均未显示对比增强。阅片者间对T2-FLAIR不匹配和CT特征的一致性极佳（κ = 1.00）。所有无T2-FLAIR不匹配征的DNET在CT上均表现为钙化。所有位于颅顶附近的DNET（5例）在肿瘤上方均表现为颅骨局部变薄。
超过半数的DNET中观察到T2-FLAIR不匹配征，该征象并非IDH突变且1p19q未缺失的弥漫性星形细胞瘤所特有。肿瘤上方的颅骨局部变薄在某些情况下可能有助于DNET的诊断。
