Functional Magnetic Resonance Imaging of Pilocytic Astrocytoma
10.3969/j.issn.1005-5185.2015.06.006
- VernacularTitle:毛细胞型星形细胞瘤的功能MRI表现
- Author:
Yun MA
;
Xiaoguang II
;
Jie HUANG
;
Houyi KANG
;
Weiguo HANG
- Publication Type:Journal Article
- Keywords:
Astrocytoma;
Brain neoplasms;
Magnetic resonance imaging;
Diffusion weighted imaging;
Diffusion tensor imaging;
Magnetic resonance spectroscopy;
Perfusion imaging;
Diagnosis,differential
- From:
Chinese Journal of Medical Imaging
2015;(6):423-427
- CountryChina
- Language:Chinese
-
Abstract:
Purpose To investigate the imaging characteristics and accuracy of diagnosing pilocytic astrocytoma (PA) with perfusion weighted imaging (PWI), diffusion weighted imaging (DWI), magnetic resonance sprectroscopy, susceptibility weighted imaging (SWI) and diffusion tensor imaging. Material and Methods MRI imaging of 11 patients with PA was retrospectively analyzed for functional imaging features. Results In 11 patients with PA, there were 9 mixed cystic and solid lesions, 1 case of cystic lesion and 1 case with solid lesion. Ten lesions showed mixed hypointensity on T1WI, and mixed hyperintensity on T2WI and FLAIR. One case was hypointense on T1WI, and hyperintense on T2WI and FLAIR. Prominent contrast enhancement was seen in the solid portion, capsular wall and mural nodules. On SWI 3 cases showed patchy low signal, 2 cases of dot-like low signal and 2 cases without low signal, with average intratumoral susceptibility signal intensity classification of 1.57. PWI findings were characterized by high perfusion with relative cerebral blood volume averaging 2.64±1.22. There was elevated choline component in the solid portion with significantly decreased NAA with average Cho/NAA ratio of 5.13±4.72 (1.46-15.26). Lactate peak was increased in 5 cases. On DWI there was limited diffusion in 1 case. 7 cases did not demonstrate limited diffusion with average relative apparent diffusion coefficient of 1.60±0.58. Conclusion Most MRI features of pilocystic astrocytoma are consistent with low grade glioma. There are characteristic functional imaging findings with higher perfusion than other gliomas. Functional MRI can evaluate tumor metabolism and prognosis.
