鼻咽癌放疗后放射性脑病的CT灌注研究  

CT perfusion imaging in radiation encephalopathy following radiotherapy for nasopharyngeal carcinoma

作　　者：林曰增[1] 张雪林[1] 阎卫平[2] 

机构地区：[1]第一军医大学南方医院影像中心,广州510515 [2]第一军医大学南方医院放疗科,广州510515

出　　处：《中华放射学杂志》2002年第4期339-343,共5页Chinese Journal of Radiology

摘　　要：目的　应用CT灌注成像观察放射性脑病微循环血流动力学变化及其病理基础 ,进一步推测放射性脑病的可能发病机制。方法　病理证实鼻咽癌 2 0例共 2 6个病灶 ,选 17个病灶对侧颞叶非病变区共 2 2个感兴趣区 (ROI) ,与颞叶病变区ROI灌注结果进行比较。结果　CT灌注图像中显示 2 6个低脑血流量 (CBF)、低脑血液容积 (CBV)病灶 ,同时也显示峰值时间 (TP)图中对比剂到达延迟。其中 2 3个颞叶病变中 ,7个颞叶坏死灶内未见血流灌注。 16个颞叶非坏死病变与 2 2个非病变区颞叶白质比较 ,非坏死病变区CBF下降 ,平均通过时间 (MTT)延长 ,其差异均具有非常显著性意义(t值分别为 7 47,9 38;P值均 <0 0 1)。TP延长不显著 (t=1 78,P >0 0 5 )。 3个桥脑放射性脑病的CBF均较正常均值降低。结论　CBF是反映放射性脑病微循环灌注的直接指标 ,其诊断意义较大。MTT、TP是反映血管阻力的参数 ,对诊断有参考价值。病灶区的微循环障碍是其重要的病理基础 ,其CBF下降 ,提示微循环障碍 ,更进一步支持了放射性脑病的血管损伤学说。Objective To evaluate the microcirculatory hemodynamic changes and the pathological basis of radiation encephalopathy (RE) by using CT perfusion imaging, and infer the possible pathogenic mechanism of RE Methods CT perfusion images were obtained in 20 patients with RE following radiotherapy for nasopharyngeal carcinoma RE were diagnosed by clinical appearances, CT, and MRI Results Twenty six areas of reduced CBF (cerebral blood flow), CBV( cerebral blood volume) and prolonged TP (time to peak) were detected with the aid of functional images in 20 patients with MRI and CT Twenty three were in the white matter of temporal lobes (TL), 3 in brain stems In the 7 necrotic areas of 23 TL lesions, no blood perfusion was observed The ±s values of CBF, MTT (mean transit time), and TP in the 16 non necrotic lesions in white matter were (14 63±5 27) ml·min -1 ·100 g -1 , (23 47±2 96) s, and (23 19±3 41) s, respectively The ±s values of CBF, MTT, and TP in the 22 normal ROIs of TL white matter were (29 57±6 61) ml·min -1 ·100 g -1 , (16 66±1 45) s, and (21 63±2 01) s, respectively CBF was much lower, MTT was much longer in the lesions than in the normal controls( P <0 01) There were very significant differences between the two groups TP was not prolonged remarkably in the lesions than in the normal controls ( P >0 05) There was a prolonged tendency between the two groups Compared with the values of CBF in the normal brain stems, the values of CBF in the 3 areas of RE in brain stems were also lower Conclusion CBF is a direct index which reflects the microcirculatory perfusion in RE and has played a great role in the diagnosis of RE MTT and TP are parameters which indicate the cerebrovascular resistance and have a reference value in RE′s diagnosis The microcirculatory disturbance in the lesion areas is the important pathologic basis of RE The decreased CBF of RE means microcirculatory disturbance, and further supports the hypothesis o

关 键 词：X线计算机体层摄影术 放射性脑病 发病机制 RE 鉴别诊断 CT灌注成像 血液动力学 鼻咽癌 

分 类 号：R739.63[医药卫生—肿瘤]