高、低级别脑星形细胞瘤瘤周区CTP研究

目的：探讨高、低级别星形细胞瘤瘤周区CT灌注成像（CTP）参数的差异及其病理基础。方法：对30例手术与病理证实的脑星形细胞瘤（低级别星形细胞瘤10例、高级别星形细胞瘤20例）行术前CT平扫、增强及CTP检查，测量强化区近侧1cm处或低强化区距边缘1cm处的脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）及脑血管表面通透性（PS）值。比较高、低级别脑星形细胞瘤瘤周区CTP参数差异。对照影像学，采用肿瘤切除前活检的方法取得标本，观察瘤周区病理表现。结果：高级别星形细胞瘤瘤周区CBF、CBV、MTT及PS值高于低级别星形细胞瘤瘤周区。CBF、CBV、MTT及PS值，高级别星形细胞瘤瘤周区分别为（50.05±14.05）ml?蛐（min·100g）、（3.50±1.79）ml?蛐100g、（5.84±2.95）s及（1.23±1.75）ml?蛐（min·100g），低级别星形细胞瘤瘤周区分别为（25.20±8.67）ml?蛐（min·100g）、（1.61±0.68）ml?蛐100g、（4.83±1.63）s及（0.33±0.27）ml?蛐（min·100g），二组间CBF、CBV差异有统计学意义（P<0.05）。组织学上，高级别与低级别星形细胞瘤瘤周区均可见散在肿瘤细胞，前者肿瘤细胞密度较大、血管较多。结论：高级别与低级别脑星形细胞瘤瘤周区CBF、CBV有明显差别，其病理基础不同。

Comparative study of peritumoral area of high-and low-grade astrocytoma with CTP

Objective： To probe the difference of CT perfusion （CTP） parameters of peritumoral area between high- and low-grade intracranial astrocytoma, and to explore the pathologic basis. Methods： Thirty cases of intracranial asytrocytoma, proven by surgery and pathologic examination, including 10 cases of low-grade tumors （WHO grade Iand II ） and 20 cases of high-grade tumors, were examined for precontrast CT, postcontrast CT and CTP. We mearsured the CTP parameters, in- cluding CBF, CBV, MTF and PS at the area of lcm from the margin of enhancement or the margin of the non-enhanced le- sion. Paired t test was made for comparison of the CTP parameters of high- and low-grade astrocytoma with the software SPSS 17.0 for refering CTP and postcontrast CT maps, biopsy was made before incision. And the pathologic findings of peri- tumoral area was observed. Results： CBF, CBV, MTT and PS of peritumoral area of high- grade astrocytoma were higher than those of low-grade astrocytoma. The CBF, CBV, MTT and PS value, peritumoral area of high-grade astrocytoma were （50.05± 14.05）ml/（min.100g）, （3.50±l.79）ml/100g, （5.84±2.95）s and （1.23±l.75）ml/（min. 100g） respectively. And low-grade astrocytoma were （25.20±8.67）ml/（min＇100g）, （1.61±0.68）ml/100g, （4.83±1.63）s and （0.33±0.27）ml/（min.100g） respectively. There were signif- icant difference of CBF and CBV between high- and low-grade astrocytoma （P〈0.05）. But no obvious difference was found for MTT and PS between high- and low-grade astrocytoma （P〉0.05）. Discrete tumor cells were detected in peritumoral area for both high- and low-grade astrocytoma. Whereas more neoplastic cells and vascularity were found in peritumoral area of high- grade astrocytoma. Conclusion： Because of different pathologic basis, there was significant distinction of CTP parameters of peritumoral area between high- and low-grade astrocytoma. This distinction is due to their different findings on pathology.