大鼠C6胶质瘤能谱CT多参数量化检测

Quantitative detection of infiltration of rat C6 glioma rat by spectral CT

目的探讨能谱CT多参数分析检测大鼠C6胶质瘤肿瘤细胞增殖活性及邻近脑组织侵袭范围的准确性,为恶性胶质瘤手术导航提供新的动态检测方法。方法 15只雄性Wista大鼠右侧基底节区种植C6胶质瘤细胞后观察并记录体征及饮食状况。荷瘤术后第12天能谱CT扫描后心脏灌注取脑固定制作病理切片进行HE及ki67染色。在GE公司AW4. 6工作站对肿瘤中心层面薄层图像数据后处理分析,测量肿瘤中心、外周及邻近脑组织单能量CT值、能谱曲线斜率及碘含量。应用SPSS 17. 0统计学分析软件分析肿瘤不同区域能谱CT各参数检查值与ki67的差异的相关性。结果 15只荷瘤鼠1只死亡,1只荷瘤失败,其余13只纳入本研究。能谱CT结果显示瘤体与邻近脑组织在65KeV可获得最佳对比噪声比,肿瘤液化坏死区、实性区、周边区及正常脑组织单能量X线衰减曲线存在显著差异,曲线斜率分别是0. 24±0. 46、1. 81±1. 09、0. 8±0. 43、0. 11±0. 27(P <0. 01),65KeV CT值分别是27. 2±4. 51、103. 18±35. 48、65. 19±13. 72、38. 07±7. 36(P <0. 01),碘浓度分别是2. 41±3. 86、32. 67±63. 27、6. 76±3. 66、1. 06±2. 35(P <0. 05),ki67阳性细胞百分比与曲线斜率、65KeV CT值(P <0. 01)及碘浓度(P <0. 05)具有相关性。结论能谱CT单能量图、能谱曲线及碘基图有助于大鼠C6胶质瘤邻近脑组织受侵袭范围的确定;单能量CT值、能谱曲线及碘含量斜率与ki67阳性细胞百分比具有相关性,可反映肿瘤细胞的增殖活性。

Objective To explore the utility of multi-parameter spectral CT analysis in the evaluation of rat C6 glioma and its invasion into adjacent brain regions,and to assess its correlation with histopathology data.Methods Fifteen male Wistar rats were seeded(right basal ganglia)with C6 glioma cells and scanned 12 days later using spectral CT.Brain sections corresponding to scanned regions were immunostained for Ki67(cell proliferation).Pearson correlations between spectral CT parameters and Ki67 expression were determined.Results Thirteen rats survived 12 days and developed tumors.Optimal contrast-to-noise ratio was at 65 keV.Brain regions containing liquefactive necrosis,solid tumor,peripheral tumor and normal tissue differed with regard to spectral curve slope(0.24±0.46,1.81±1.09,0.8±0.43 and 0.11±0.27,respectively;P﹤0.01),CT value(27.2±4.51,103.18±35.48,65.19±13.72 and 38.07±7.36,respectively;P﹤0.01)and iodine concentration(2.41±3.86,16.05±9.75,6.76±3.66 and 1.06±2.35,respectively;P﹤0.0001).The percentage of Ki67-positive cells correlated with CT value(r=0.903,P﹤0.001),spectral curve slope(r=0.821,P﹤0.001)and iodine concentration(r=0.813,P﹤0.001).Conclusion Spectral CT can detect microstructural changes within malignant gliomas and potentially provide important information about tumor proliferation and the extent of the invasion.