Danchaivijitr Nasuda, Waldman Adam D, Tozer Daniel J, Benton Christopher E, Brasil Caseiras Gisele, Tofts Paul S, Rees Jeremy H, Jäger H Rolf
Institute of Neurology, University College London, Queen Square, London WC1 3BG, UK.
Radiology. 2008 Apr;247(1):170-8. doi: 10.1148/radiol.2471062089.
To prospectively perform longitudinal magnetic resonance (MR) perfusion imaging of conservatively treated low-grade gliomas to determine whether relative cerebral blood volume (rCBV) changes precede malignant transformation as defined by conventional MR imaging and clinical criteria.
All patients gave written informed consent for this institutional ethics committee-approved study. Thirteen patients (seven men, six women; age range, 29-69 years) with biopsy-proved low-grade glioma treated only with antiepileptic drugs were examined longitudinally with susceptibility-weighted perfusion, T2-weighted, fluid-attenuated inversion recovery, and high-dose contrast material-enhanced T1-weighted MR imaging at 6-month intervals to date or until malignant transformation was diagnosed. Student t tests were used to determine differences in rCBV values between "transformers" and "nontransformers" at defined time points throughout study follow-up.
Seven patients showed progression to high-grade tumors between 6 and 36 months (mean, 22.3 months), and disease in six patients remained stable over a period of 12-36 months (mean, 23 months). Transformers had a slightly (but not statistically significantly) higher group mean rCBV than nontransformers at the point of study entry (1.93 vs 1.31). In nontransformers, the rCBV remained relatively stable and increased to only 1.52 over a mean follow-up of 23 months. In contrast, transformers showed a continuous increase in rCBV up to the point of transformation, when contrast enhancement became apparent on T1-weighted images. The group mean rCBV was 5.36 at transformation but also showed a significant increase from the initial study at 12 months (3.14, P = .022) and at 6 months (3.65, P = .049) before transformation. Rates of rCBV change between two successive time points were also significantly higher in transformers than in nontransformers.
In transforming low-grade glioma, susceptibility-weighted MR perfusion imaging can demonstrate significant increases in rCBV up to 12 months before contrast enhancement is apparent on T1-weighted MR images.
对经保守治疗的低级别胶质瘤进行前瞻性纵向磁共振（MR）灌注成像，以确定相对脑血容量（rCBV）变化是否先于根据传统MR成像和临床标准定义的恶性转化。
所有患者均为本机构伦理委员会批准的研究提供了书面知情同意书。13例经活检证实为低级别胶质瘤且仅接受抗癫痫药物治疗的患者（7例男性，6例女性；年龄范围29 - 69岁），每隔6个月进行纵向的敏感性加权灌注成像、T2加权成像、液体衰减反转恢复成像以及高剂量对比剂增强T1加权MR成像检查，直至确诊恶性转化或截至目前。在整个研究随访期间的特定时间点，采用学生t检验来确定“转化者”和“非转化者”之间rCBV值的差异。
7例患者在6至36个月（平均22.3个月）内进展为高级别肿瘤，6例患者的病情在12至36个月（平均23个月）内保持稳定。在研究开始时，“转化者”的组平均rCBV略高于“非转化者”（1.93对1.31，但无统计学显著差异）。在“非转化者”中，rCBV保持相对稳定，在平均23个月的随访中仅增加到1.52。相比之下，“转化者”在转化点之前rCBV持续增加，此时T1加权图像上出现对比增强。转化时的组平均rCBV为5.36，但与初始研究时相比，在转化前12个月（3.14，P = .022）和6个月（3.65，P = .049）也有显著增加。“转化者”两个连续时间点之间rCBV变化率也显著高于“非转化者”。
在转化性低级别胶质瘤中，敏感性加权MR灌注成像可显示在T1加权MR图像上出现对比增强之前长达12个月的rCBV显著增加。
