PWI和DWI技术在鉴别脑胶质瘤复发与放射性脑损伤中的价值

目的分析MR灌注加权成像（PWI）和扩散加权成像（DWI）在鉴别脑胶质瘤复发与放射性损伤中的价值。材料与方法选取30例脑胶质瘤术后、放疗后常规MR增强序列出现新强化灶的患者。30例患者均行常规MR平扫、DWI、增强扫描和PWI检查。比较异常强化区与对侧正常区的参数比值，包括相对脑血容量（rCBV）、相对脑血流量（rCBF）、相对平均通过时间（rMTT）及ADC比值。结果30例患者最终经手术和随访证实有20例胶质瘤复发，10例放射性脑损伤。胶质瘤复发组rCBV、rCBF比值的M值分别为2.11（范围1.03～4.72）、1.895（范围0.8～4.56），明显高于放射性损伤组比值rCBV为0.53（范围0.24～1.10）、rCBF为0.515（范围0.2～1.02），差异有统计学意义（P值均＆lt;0.05）。胶质瘤复发ADC比值略低于放射性脑损伤ADC比值，但在统计学上无明显差异。结论 PWI技术可以较好的鉴别脑胶质瘤复发和放射性损伤。DWI技术对二者鉴别具有一定的参考作用。

Differentiation between recurrent glioma and radiation-induced brain injuries using perfusion weighted imaging and diffusion weighted imaging

Objective：To evaluate the perfusion weighted imaging （PWI） and diffusion weighted imaging （DWI） in the differentiation of recurrent glioma and radiation-induced brain injuries. Materials and Methods：30 patients with glioma having radiotherapy after surgery, presenting newly developed abnormal enhancement, were included in the study. The MR examintions comprised of conventional MR imaging, DWI and PWI. Comparison of abnormal enhancement parameter ratio area and contralateral normal area, including the relative cerebral blood volume （rCBV）, relative cerebral blood lfow （rCBF）, relative mean transit time （rMTT） and the ratio of ADC. Results：Twenty of the 30 patients were proved glioma recurrence, ten were proved radiation-induced brain injuries. The mean rCBV ratio 2.11 （range 1.03-4.72） in glioma recurrence was higher than that 0.53 （range 0.24-1.10） in radiation injuries （P＆lt;0.05）. The mean rCBF ratio 1.895 （range 0.8-4.56） in glioma recurrence was higher than that 0.515 （range 0.2-1.02） in radiation injuries （P＆lt;0.05）. Resutls obtained in DWI were not statistically signiifcant different between two analysed groups. The ADC ratio of glioma recurrence is slightly lower than the ADC ratio of radiation-induced brain injuries. Conclusions：PWI seems to be most reliable in differentiation between glioma recurrence and radiation-induced brain injuries. DWI do not differentiate analyzed groups with statistical signiifcance, despite tendency to lower ADC values in recurrence group than in radiation-induced brian injuries.