Kono K, Inoue Y, Nakayama K, Shakudo M, Morino M, Ohata K, Wakasa K, Yamada R
Department of Radiology, Izumi Municipal Hospital, Izumi-shi , Osaka, Japan.
AJNR Am J Neuroradiol. 2001 Jun-Jul;22(6):1081-8.
Diffusion-weighted images (DWIs) have been used to study various diseases, particularly since echo-planar techniques shorten examination time. Our hypothesis was that DWIs and tumor apparent diffusion coefficients (ADCs) could provide additional useful information in the diagnosis of patients with brain tumors.
Using a 1.5-T MR unit, we examined 56 patients with histologically verified or clinically diagnosed brain tumors (17 gliomas, 21 metastatic tumors, and 18 meningiomas). We determined ADC values and signal intensities on DWIs both in the solid portion of the tumor and in the peritumoral, hyperintense areas on T2-weighted images. We also evaluated the correlation between ADC values and tumor cellularity in both gliomas and meningiomas.
The ADCs of low-grade (grade II) astrocytomas were significantly higher (P =.0004) than those of other tumors. Among astrocytic tumors, ADCs were higher in grade II astrocytomas (1.14 +/- 0.18) than in glioblastomas (0.82 +/- 0.13). ADCs and DWIs were not useful in determining the presence of peritumoral neoplastic cell infiltration. The ADC values correlated with tumor cellularity for both astrocytic tumors (r = -.77) and meningiomas (r = -.67).
The ADC may predict the degree of malignancy of astrocytic tumors, although there is some overlap between ADCs of grade II astrocytomas and glioblastomas.
扩散加权成像（DWI）已被用于研究各种疾病，特别是自从回波平面技术缩短了检查时间以来。我们的假设是，DWI和肿瘤表观扩散系数（ADC）可为脑肿瘤患者的诊断提供额外有用信息。
使用1.5-T磁共振设备，我们检查了56例经组织学证实或临床诊断为脑肿瘤的患者（17例胶质瘤、21例转移瘤和18例脑膜瘤）。我们测定了肿瘤实体部分以及T2加权图像上肿瘤周围高信号区域的ADC值和DWI信号强度。我们还评估了胶质瘤和脑膜瘤中ADC值与肿瘤细胞密度之间的相关性。
低级别（II级）星形细胞瘤的ADC值显著高于其他肿瘤（P = 0.0004）。在星形细胞肿瘤中，II级星形细胞瘤的ADC值（1.14±0.18）高于胶质母细胞瘤（0.82±0.13）。ADC和DWI在确定肿瘤周围肿瘤细胞浸润的存在方面并无用处。ADC值与星形细胞肿瘤（r = -0.77）和脑膜瘤（r = -0.67）的肿瘤细胞密度均相关。
ADC可能预测星形细胞肿瘤的恶性程度，尽管II级星形细胞瘤和胶质母细胞瘤的ADC值存在一定重叠。
