Data_Sheet_1_Comparison of Canine and Feline Meningiomas Using the Apparent Diffusion Coefficient and Fractional Anisotropy.PDF

Meningiomas are the most common intracranial tumor in dogs and cats, and their surgical resection is often performed because they are present on the brain surface. Typical meningiomas show comparatively characteristic magnetic resonance imaging findings that lead to clinical diagnosis; however, it is necessary to capture not only macroscopic changes but also microstructural changes to devise a strategy for surgical resection and/or quality of removal. To visualize such microstructural changes, diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) have been used in human medicine. The aim of this retrospective study was to investigate the different characteristics of the apparent diffusion coefficient (ADC) from DWI and fractional anisotropy (FA) from DTI of meningioma between dogs and cats. Statistical analyses were performed to compare ADC and FA values between the intratumoral or peritumoral regions and normal-appearing white matter (NAWM) among 13 dogs (13 lesions, but 12 each in ADC and FA analysis) and six cats (seven lesions). The NAWM of cats had a significantly lower ADC and higher FA compared to dogs. Therefore, for a comparison between dogs and cats, we used ADC and FA ratios that were calculated by dividing the subject (intra- or peritumoral) ADC and FA values by those of NAWM on the contralateral side. Regarding the intratumoral region, feline meningiomas showed a significantly lower ADC ratio and higher FA ratio than canine meningiomas. This study suggested that ADC and FA may be able to distinguish a meningioma that is solid and easy to detach, like as typical feline meningiomas.

脑膜瘤是犬与猫最常见的颅内肿瘤，因其多附着于脑表面，临床通常需行手术切除。典型脑膜瘤具有较为特征性的磁共振成像（magnetic resonance imaging）表现，可辅助临床诊断；但为制定手术切除方案并评估切除质量，不仅需捕捉宏观形态变化，还需明确微观结构改变。为可视化此类微观结构改变，人类医学领域已采用扩散加权成像（diffusion-weighted imaging, DWI）与扩散张量成像（diffusion tensor imaging, DTI）技术。本回顾性研究（retrospective study）旨在对比犬与猫脑膜瘤的扩散加权成像衍生表观扩散系数（apparent diffusion coefficient, ADC），以及扩散张量成像衍生各向异性分数（fractional anisotropy, FA）的差异特征。研究纳入13只犬（共13个病灶，其中ADC与FA分析各纳入12个病灶）及6只猫（共7个病灶），通过统计学分析对比瘤内、瘤周区域与正常表现脑白质（normal-appearing white matter, NAWM）的ADC与FA值。结果显示，猫的正常表现脑白质ADC值显著低于犬，而FA值显著高于犬。因此，为消除物种间基线差异以开展跨物种对比，本研究采用比值法：将瘤内或瘤周区域的ADC、FA值除以对侧正常表现脑白质的对应值，得到校正后的ADC比值与FA比值。针对瘤内区域，猫脑膜瘤的校正ADC比值显著低于犬脑膜瘤，而校正FA比值显著高于犬脑膜瘤。本研究结果表明，ADC与FA或可用于区分质地坚实、易于剥离的典型猫脑膜瘤。