Vasireddi Anil K, Reinshagen Katherine L, Shin Donghoon, Romo Laura V, Juliano Amy F
From the Department of Radiology (A.K.V., D.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Department of Radiology (K.L.R, L.V.R., A.F.J.), Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts.
AJNR Am J Neuroradiol. 2025 Feb 3;46(2):349-354. doi: 10.3174/ajnr.A8452.
This study investigates the practicality and utility of the "outline sign," which refers to the thin curvilinear hyperenhancing line that may be seen along the margin of a meningioma on a spin-echo postcontrast T1-weighted image. For cases in which the differential diagnosis may include other tumors, visualization of the outline sign may help to increase the diagnostic confidence for a meningioma. Therefore, in the temporal bone region such as the cerebellopontine angle or jugular foramen, where differential considerations may include a schwannoma or paraganglioma, we additionally investigated whether the outline sign may be observed in these nonmeningioma lesions.
A total of 39 clinical MRIs of meningiomas, schwannomas, and paragangliomas with confirmed histopathologic data were studied retrospectively. Two experienced head and neck radiologists independently assessed for the presence or absence of an outline sign and subsequently formed a consensus opinion while blinded to patient information and histopathologic data. Interreader reliability was assessed by Cohen κ statistics. Simple bivariate comparisons were performed on the consensus opinions to assess for statistical differences in presence of the sign in meningiomas versus schwannomas and paragangliomas. Sensitivity, specificity, and accuracy of the sign with respect to identifying an underlying meningioma were calculated.
Both readers displayed identical opinions in assessment of the outline sign in 34 of the 39 cases (87%), including 13 of the 14 meningiomas (93%), with substantial agreement (Cohen κ of 0.74). The outline sign was present in 12 of 14 meningiomas (86%), which was significantly greater in frequency compared with schwannomas (3 of 22, 14%) and paragangliomas (1 of 3, 33%). The outline sign demonstrated high sensitivity (86%), specificity (84%), and accuracy (85%) in identifying an underlying meningioma.
The outline sign can serve as a useful tool for diagnosing meningiomas. It may help distinguish meningiomas from other enhancing tumors, for example schwannomas and paragangliomas in the temporal bone region.
本研究探讨“轮廓征”的实用性和应用价值，“轮廓征”指的是在自旋回波增强后T1加权图像上沿脑膜瘤边缘可见的细曲线状强化线。对于鉴别诊断可能包括其他肿瘤的病例，轮廓征的显示可能有助于提高脑膜瘤的诊断置信度。因此，在颞骨区域，如桥小脑角或颈静脉孔，鉴别诊断可能包括神经鞘瘤或副神经节瘤，我们额外研究了这些非脑膜瘤病变中是否能观察到轮廓征。
回顾性研究了39例具有确诊组织病理学数据的脑膜瘤、神经鞘瘤和副神经节瘤的临床MRI。两名经验丰富的头颈放射科医生在不知道患者信息和组织病理学数据的情况下，独立评估轮廓征的有无，随后形成共识意见。通过Cohen κ统计量评估阅片者间的可靠性。对共识意见进行简单的双变量比较，以评估脑膜瘤与神经鞘瘤和副神经节瘤中该征出现情况的统计学差异。计算该征识别潜在脑膜瘤的敏感性、特异性和准确性。
在39例病例中的34例（87%），两位阅片者对轮廓征的评估意见一致，包括14例脑膜瘤中的13例（93%），一致性良好（Cohen κ为0.74）。14例脑膜瘤中有12例（86%）出现轮廓征，其出现频率显著高于神经鞘瘤（22例中的3例，14%）和副神经节瘤（3例中的1例，33%）。轮廓征在识别潜在脑膜瘤方面显示出高敏感性（86%）、特异性（84%）和准确性（85%）。
轮廓征可作为诊断脑膜瘤的有用工具。它可能有助于将脑膜瘤与其他强化肿瘤区分开来，例如颞骨区域的神经鞘瘤和副神经节瘤。
