Wang Yu-lin, Liu Meng-yu, Wang Yan, Xiao Hua-feng, Sun Lu, Zhang Jun, Ma Lin
Department of Radiology,Chinese PLA General Hospital, Beijing,China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2013 Aug;35(4):416-21. doi: 10.3881/j.issn.1000-503X.2013.04.011.
To evaluate the role of perfusion weighted imaging (PWI) in the differentiation between recurrent glioma and radiation-induced brain injuries.
Twenty-three patients with previously resected and irradiated glioma, presenting newly developed abnormal enhancement, were included in the study. The final diagnosis was determined either histologically or clinicoradiologically. PWI was obtained with a gradient echo echo-planar-imaging (GRE-EPI)technique. The normalized relative cerebral blood volume (rCBV) ratio [rCBV (abnormal enhancement)/rCBV (contralateral tissue)], relative cerebral blood flow (rCBF) ratio [rCBF (abnormal enhancement)/rCBF(contralateral tissue)], mean transit time(MTT) ratio [MTT (abnormal enhancement)/MTT(contralateral tissue)],time to peak(TTP)ratio[TTP(abnormal enhancement)/TTP(contralateral tissue)],and bolus arrive time(BAT)ratio[BAT(abnormal enhancement)/BAT(contralateral tissue)] were calculated. The regions of interest (ROIs) consisting of 20-40mm(2) were placed in the abnormal enhanced areas on postcontrast T1-weighted images.Ten ROIs measurements were performed in each lesion.T test was used to determine whether there was a difference in the rCBV/rCBF/rMTT/rTTP/rBAT ratios between recurrent glioma and irradiated injuries.Significance was set to a P value <0.05.
Thirteen of the 23 patients were proved recurrent glioma and 10 were proved radiation-induced brain injuries. The rCBV ratio (3.60±3.86 vs. 0.82 ± 0.74, P = 0.000)and rCBF ratio (2.88 ± 2.27 vs. 0.84 ± 0.80, P = 0.000) in glioma recurrence were markedly higher than those in radiation injuries. The areas under rCBV and rCBF ROC curve were both 0.8763. rMTT (P=0.204), rTTP (P=0.260), and rBAT (P=0.071) ratios showed no statistical difference between the two groups.
PWI is an effective technique in distinguishing glioma recurrence from radiation injuries,and the ratios of rCBV and rCBF ratio differential diagnosis of critical value to 1.3088 and 1.1235, respectively, can be used as a reliable clinical indicator.
评估灌注加权成像（PWI）在鉴别复发性胶质瘤与放射性脑损伤中的作用。
本研究纳入23例既往有胶质瘤切除及放疗史、出现新的异常强化的患者。最终诊断通过组织学或临床放射学方法确定。采用梯度回波平面回波成像（GRE-EPI）技术进行PWI检查。计算标准化相对脑血容量（rCBV）比值[rCBV（异常强化区）/rCBV（对侧组织）]、相对脑血流量（rCBF）比值[rCBF（异常强化区）/rCBF（对侧组织）]、平均通过时间（MTT）比值[MTT（异常强化区）/MTT（对侧组织）]、达峰时间（TTP）比值[TTP（异常强化区）/TTP（对侧组织）]以及团注到达时间（BAT）比值[BAT（异常强化区）/BAT（对侧组织）]。在增强后T1加权图像上，将20 - 40mm²的感兴趣区（ROI）置于异常强化区域。每个病灶进行10次ROI测量。采用t检验确定复发性胶质瘤与放射性损伤之间rCBV/rCBF/rMTT/rTTP/rBAT比值是否存在差异。显著性水平设定为P值<0.05。
23例患者中，13例被证实为复发性胶质瘤，10例被证实为放射性脑损伤。胶质瘤复发时的rCBV比值（3.60±3.86 vs. 0.82±0.74，P = 0.000）和rCBF比值（2.88±2.27 vs. 0.84±0.80，P = 0.000）显著高于放射性损伤。rCBV和rCBF的ROC曲线下面积均为0.8763。rMTT（P = 0.204）、rTTP（P = 0.260）和rBAT（P = 0.071）比值在两组之间无统计学差异。
PWI是鉴别胶质瘤复发与放射性损伤的有效技术，rCBV和rCBF比值的鉴别诊断临界值分别为1.3088和1.1235，可作为可靠的临床指标。
