Neuroradiology, Universitätsmedizin, Georg-August-University Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Germany.
J Neurooncol. 2013 Apr;112(2):217-22. doi: 10.1007/s11060-013-1049-y. Epub 2013 Jan 24.
The most frequent primary brain tumors, anaplastic astrocytomas (AA) and glioblastomas (GBM): tend to invasion of the surrounding brain. Histopathological studies found malignant cells in macroscopically unsuspicious brain parenchyma remote from the primary tumor, even affecting the contralateral hemisphere. In early stages, diffuse interneural infiltration with changes of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) is suspected. The purpose of this study was to investigate the value of DTI as a possible instrument of depicting evidence of tumor invasion into the corpus callosum (CC). Preoperatively, 31 patients with high-grade brain tumors (8 AA and 23 GBM) were examined by MRI at 3 T, applying a high-resolution diffusion tensor imaging (DTI) sequence. ADC- and FA-values were analyzed in the tumor-associated area of the CC as identified by fiber tracking, and were compared to matched healthy controls. In (MR-)morphologically normal appearing CC the ADC values were elevated in the tumor patients (n = 22; 0.978 × 10(-3) mm²/s) compared to matched controls (0.917 × 10(-3) mm²/s, p < 0.05), and the corresponding relative FA was reduced (rFA: 88 %, p < 0.01). The effect was pronounced in case of affection of the CC visible on MRI (n = 9; 0.978 × 10(-3) mm²/s, p < 0.05; rFA: 72 %, p < 0.01). Changes in diffusivity and anisotropy in the CC can be interpreted as an indicator of tumor spread into the contralateral hemisphere not visible on conventional MRI.
最常见的原发性脑肿瘤，间变性星形细胞瘤（AA）和胶质母细胞瘤（GBM）：往往侵袭周围的大脑。组织病理学研究发现，在远离原发肿瘤的宏观上无可疑的脑实质中存在恶性细胞，甚至影响对侧大脑半球。在早期阶段，弥漫性神经内浸润，表观扩散系数（ADC）和各向异性分数（FA）发生变化，故推测弥散张量成像（DTI）可能有助于显示肿瘤向胼胝体（CC）侵袭的证据。术前，对 31 例高级别脑肿瘤患者（8 例 AA 和 23 例 GBM）进行了 3T 磁共振成像（MRI）检查，应用高分辨率弥散张量成像（DTI）序列。通过纤维跟踪术分析肿瘤相关区域的 ADC 和 FA 值，并与匹配的健康对照组进行比较。在（MR）形态上正常的 CC 中，肿瘤患者（n = 22）的 ADC 值升高（0.978×10(-3)mm²/s），与匹配对照组（0.917×10(-3)mm²/s，p < 0.05）相比，相应的相对 FA 降低（rFA：88%，p < 0.01）。在 MRI 可见 CC 受累的情况下（n = 9），这种影响更为明显（0.978×10(-3)mm²/s，p < 0.05；rFA：72%，p < 0.01）。CC 中的弥散性和各向异性变化可解释为肿瘤向对侧半球扩散的指标，在常规 MRI 上不可见。
