Aprile I, Giorgi C, Guiducci A, Conti G, Ottaviano I, Ottaviano P
Diagnostica Immagini, Neuroradiologia; Terni, Italy -
Neuroradiol J. 2008 Apr 7;21(2):196-203. doi: 10.1177/197140090802100207.
The tissues placed on the edge of a glioblastoma's necrotic cavities are more vascularized than other pseudocystic central nervous system (CNS) tumours, both benign and malignant. The post-contrast enhancement is greater in Fluid-Attenuated Inversion-Recovery (FLAIR) images than in Spin Echo T1-weighted (SE T1w) sequences above all in the CNS tissues with a low concentration of gadolinium. The purpose of this study was to distinguish pseudocystic glioblastomas from other cystic CNS tumors by comparing post-contrast pseudocystic rim enhancement in FLAIR and SE T1-w magnetic resonance (MR) images. We investigated 32 extensive sets of MR images relating to histologically diagnosed pseudocystic CNS tumors; 14/32 were glioblastoma. Fast Spin Echo (FSE) T2-weighted and Proton Density, SE T1w and FSE FLAIR sequences were acquired in all the studies. After contrast media administration SE T1w and FLAIR sequences were acquired. In post-contrast T1w SE and T2w FLAIR acquisitions, pseudocyst rim enhancement was evaluated assigning scores: 4 = rim enhancement completely surrounds perimeter; 3 = rim enhancement in ≥50% of perimeter; 2 = rim in < 50% of perimeter; 1 = rim enhancement absent. Mean scores were calculated and the results were compared with statistical methods (Student's t test) for glioblastomas and all other tumors. Moreover differences between FLAIR and SE scores was assessed in each patient. If the difference was 0 glioblastoma was assumed, if the difference was ≥ 1 another tumor was assumed; the sensitivity and specificity of this diagnosis compared to the histological diagnosis were assessed. Mean T1-weighted SE scores did not differ in glioblastomas and other tumors. FLAIR scores in glioblastomas were less than half those of other tumors (p < 0.005). Glioblastoma diagnosis based on score difference identified 13 true positives (glioblastomas), 16 true negatives (non glioblastomas), two false positives and two false negatives. The sensitivity for glioblastoma was 86.7% and the specificity was 94.1%. Comparison of post-contrast rim enhancement in T1w SE and FLAIR sequences distinguishes glioblastomas from other pseudocystic CNS tumors, assisting the differential diagnosis of glioblastomas, that in many cases are not distinguishable from metastases even with advanced MR techniques.
与其他良性和恶性的假性囊性中枢神经系统（CNS）肿瘤相比，位于胶质母细胞瘤坏死腔边缘的组织血管化程度更高。在液体衰减反转恢复（FLAIR）图像中，对比剂增强后的信号高于自旋回波T1加权（SE T1w）序列，尤其是在钆浓度较低的CNS组织中。本研究的目的是通过比较FLAIR和SE T1加权磁共振（MR）图像中对比剂增强后的假性囊肿边缘强化情况，将假性囊性胶质母细胞瘤与其他囊性CNS肿瘤区分开来。我们研究了32组经组织学诊断的假性囊性CNS肿瘤的MR图像；其中14/32为胶质母细胞瘤。所有研究均采集了快速自旋回波（FSE）T2加权和质子密度、SE T1w和FSE FLAIR序列。注射对比剂后，采集SE T1w和FLAIR序列。在对比剂增强后的T1w SE和T2w FLAIR图像中，对假性囊肿边缘强化进行评分：4分 = 边缘强化完全环绕周长；3分 = 边缘强化占周长≥50%；2分 = 边缘强化占周长<50%；1分 = 无边缘强化。计算平均得分，并采用统计方法（Student's t检验）将胶质母细胞瘤与所有其他肿瘤的结果进行比较。此外，还评估了每位患者FLAIR和SE得分之间的差异。如果差异为0，则诊断为胶质母细胞瘤；如果差异≥1，则诊断为其他肿瘤；评估该诊断与组织学诊断相比的敏感性和特异性。胶质母细胞瘤和其他肿瘤的平均T1加权SE得分无差异。胶质母细胞瘤的FLAIR得分不到其他肿瘤的一半（p < 0.005）。基于得分差异的胶质母细胞瘤诊断识别出13个真阳性（胶质母细胞瘤）、16个真阴性（非胶质母细胞瘤）、2个假阳性和2个假阴性。胶质母细胞瘤的敏感性为86.7%，特异性为94.1%。对比剂增强后T1w SE和FLAIR序列中边缘强化情况的比较可将胶质母细胞瘤与其他假性囊性CNS肿瘤区分开来，有助于胶质母细胞瘤的鉴别诊断，在许多情况下，即使采用先进的MR技术，胶质母细胞瘤也难以与转移瘤区分开来。
