Guo Alexander C, Cummings Thomas J, Dash Rajesh C, Provenzale James M
Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710, USA.
Radiology. 2002 Jul;224(1):177-83. doi: 10.1148/radiol.2241010637.
To determine if water diffusivity within lymphomas and high-grade astrocytomas correlates with cellularity.
Echo-planar diffusion-weighted magnetic resonance (MR) images obtained in 11 patients with brain lymphomas (19 lesions) and in 17 patients with astrocytomas (19 lesions) were retrospectively reviewed. Regions of interest were drawn on apparent diffusion coefficient (ADC) maps in enhancing tumor. ADC values were normalized by dividing ADC values of tumors by those of normal-appearing regions and expressing the quotient as a ratio. Histologic samples from 11 patients with astrocytomas (11 lesions) and seven patients with lymphoma (seven lesions) were reviewed. Cellularity was measured by calculating the percentage of nuclear area and the percentage of cytoplasmic area and expressing the results as the nuclear-to-cytoplasmic (N/C) ratio. The ADC and N/C ratios of both tumor types were compared by using a two-tailed t test.
Mean ADC ratio of lymphomas was 1.15 (SD, 0.33; standard error of the mean [SEM], 0.10), and that of high-grade astrocytomas was 1.68 (SD, 0.48; SEM, 0.11) (P <.01). Mean N/C ratio of lymphoma was 1.45 (SD, 0.94; SEM, 0.36), and that of high-grade astrocytomas was 0.24 (SD, 0.18; SEM, 0.05) (P <.01).
Measurements of water diffusivity and cellularity suggest that higher cellularity contributes to more restricted diffusion.
确定淋巴瘤和高级别星形细胞瘤内的水扩散率是否与细胞密度相关。
回顾性分析了11例脑淋巴瘤患者（19个病灶）和17例星形细胞瘤患者（19个病灶）的回波平面扩散加权磁共振（MR）图像。在增强肿瘤的表观扩散系数（ADC）图上绘制感兴趣区。通过将肿瘤的ADC值除以正常外观区域的ADC值并将商表示为比率来对ADC值进行归一化。回顾了11例星形细胞瘤患者（11个病灶）和7例淋巴瘤患者（7个病灶）的组织学样本。通过计算核面积百分比和细胞质面积百分比并将结果表示为核质比（N/C）来测量细胞密度。使用双尾t检验比较两种肿瘤类型的ADC和N/C比率。
淋巴瘤的平均ADC比率为1.15（标准差，0.33；平均标准误[SEM]，0.10），高级别星形细胞瘤的平均ADC比率为1.68（标准差，0.48；SEM，0.11）（P<.01）。淋巴瘤的平均N/C比率为1.45（标准差，0.94；SEM，0.36），高级别星形细胞瘤的平均N/C比率为0.24（标准差，0.18；SEM，0.05）（P<.01）。
水扩散率和细胞密度的测量结果表明，较高的细胞密度导致扩散受限程度更高。
