128层螺旋CT全脑灌注诊断脑肿瘤的应用研究

目的 评价128 层螺旋CT 全脑灌注成像对脑肿瘤的诊断价值及其临床意义。方法回顾性分析经手术和病理组织学证实的36 例脑肿瘤患者的全脑CT 灌注成像资料。采用西门子128 层螺旋CT 行全脑CT 灌注成像，通过灌注分析软件获得时间-密度曲线（TDC) ，观测脑肿瘤和对侧脑组织的血流量（CBF）、血容量（CBV）、峰值时间（TTP）和毛细血管表面通透性（PS）等灌注参数，借助三点分级法评价单纯轴位图像与多维全脑灌注图像之间的差异，并对灌注参数进行统计学分析。结果在所有病例中，多维全脑灌注图像平均视觉评价分数明显高于单纯轴向灌注图（t＝-11.852，P＝0.000) ，且对病变定位更为精确。不同种类脑肿瘤TDC 具有各自不同特征，高级别胶质瘤TDC呈速升速降型，脑膜瘤与转移瘤均呈速升缓降型，有助于其鉴别诊断。统计学分析显示，肿瘤与对侧正常脑组织之间CBF、CBv 及PS值的差异均有统计学意义（P＜0.01),3种脑肿瘤之间CBF、TTP 和PS 值差异亦有统计学意义（P＜0.05）。结论 128 层螺旋CT 灌注成像结合CT 增强可用于全面评估脑血流灌注状态，有利于脑肿瘤的术前整体评估和精确定位；时间一密度曲线和灌注参数可用于量化分析和鉴定脑肿瘤的类型。

Application value of 128-slice four-dimensional spiral CT whole-brain perfusion imaging in brain tumors

Objective To evaluate the diagnostic value and the clinical significance of 128-slice spiral CT whole-brain perfusion imaging in brain tumors.Methods The whole-brain CT perfusion（CTP） imaging data of 36 patients with brain tumor confirmed surgically and pathologically were analyzed retrospectively.A Siemens 128-slice spiral CT scanner was used to perform the whole-brain CTP imaging.A perfusion analysis software was used to obtain time-density curves（TDC）,and observe the tumorous and contralateral brain tissular blood flow（CBF）,blood volume（CBV）,time to peak（TTP）,and capillary permeability surface（PS） values.The difference between the simple axis images and the entire brain images was evaluated,and these CTP parameters were analyzed statistically.Results The average visual rating scores of whole-brain perfusion images were significantly higher than that of axial perfusion images in all cases（t=-11.852,P=0.000）,and the whole-brain perfusion images were more precise in positioning a brain tumour.Different types of brain tumors have their own different characteristics TDCs,which were made for their differential diagnosis.The trend high-grade gliomas showed up speed downhill-type,and while the meningiomas and metastatic tumors showed a speed up slow down-type.Statistics analysis indicated that there was significant difference（P〈0.01） between tumorous and contralateral brain tissue,and among the three types of brain tumorous perfusion parameters（CBF,TTP and PS）.Conclusion 128-slice spiral CT perfusion imaging combination of enhanced CT scan can be used to evaluate blood perfusion of the whole human brain,and make preoperative overall assessment and precise positioning for brain tumors.The TDCs and perfusion parameters can be used for quantitative analysis and identifing the category of the brain tumors.