Yamaguchi N, Kawase T, Sagoh M, Ohira T, Shiga H, Toya S
Department of Neurosurgery, School of Medicine, Keio University, Tokyo, Japan.
Surg Neurol. 1997 Dec;48(6):579-83. doi: 10.1016/s0090-3019(96)00439-9.
The consistency of a meningioma is one of the important factors in determining the surgical outcome. If the surgeon is aware of the consistency of a meningioma preoperatively, the surgical plans will be influenced. A few papers have described the correlation between consistency of meningiomas and their magnetic resonance imaging (MRI) findings. However, prediction of consistency with MRI is still difficult. We have tried to predict the consistency of meningiomas with MRI findings more precisely.
Fifty patients diagnosed as having intracranial meningiomas were studied with 1.5 Tesla MRI. We compared the MRI findings with tumor consistency. The intensities of the tumors were categorized into three grades (low, iso, and high) compared to that of the gray matter. T1-weighted images had no specifics, but T2-weighted images and proton density images were useful for the prediction of tumor consistency. Hyperintensity on protein density (PD) and T2-weighted images was a sign of a soft tumor.
We presume that T2 and PD are useful for predicting consistency of meningiomas, and their water content is one of the main factors in their consistency. Histology may be one of the factors helpful in defining the consistency of a tumor. In this series, we found no relationship between histology and MRI findings, nor between histology and consistency. If the meningioma is believed to be hard, preoperative endovascular embolization is beneficial, which will induce necrosis of the meningioma and make it soft enough to be removed more easily and safety.
脑膜瘤的质地是决定手术结果的重要因素之一。如果外科医生在术前了解脑膜瘤的质地，手术方案将会受到影响。已有几篇论文描述了脑膜瘤质地与其磁共振成像（MRI）表现之间的相关性。然而，通过MRI预测质地仍然困难。我们试图更精确地通过MRI表现预测脑膜瘤的质地。
对50例诊断为颅内脑膜瘤的患者进行了1.5特斯拉MRI检查。我们将MRI表现与肿瘤质地进行了比较。与灰质相比，肿瘤的信号强度分为三个等级（低、等、高）。T1加权图像无特异性，但T2加权图像和质子密度图像对预测肿瘤质地有用。质子密度（PD）和T2加权图像上的高信号是软肿瘤的征象。
我们推测T2和PD对预测脑膜瘤质地有用，且其含水量是影响质地的主要因素之一。组织学可能是有助于确定肿瘤质地的因素之一。在本系列研究中，我们未发现组织学与MRI表现之间、组织学与质地之间存在关联。如果认为脑膜瘤质地硬，术前血管内栓塞有益，这将导致脑膜瘤坏死并使其质地变软，从而更容易、更安全地切除。
