Abstract：Objective: To explore the imaging features of different grades of oligodendrogliomas and pathological results for guidance of treatment. Methods: Imaging findings of 57 oligodenodrogliomas of different grades confirmed by pathology were retrospectively analyzed. Results: Thirty-five patients were grade Ⅱ oligodendrogliomas(WHO Ⅱ grade), with a median age of 34 years. Most of the tumors occurred in the cortical and medullary junction of parietal and frontal lobes, with ill defined boundary. 29 cases were slightly low density and 6 cases were mixed density on CT. On T1WI, 31 cases showed low signal and 4 showed equal signal. On T2WI, 35 cases showed high signal. Enhanced CT scan showed mild enhancement in 32 cases and heterogeneous enhancement in 3 cases. Thirty-two cases had calcification; 7 cases had cystic degeneration; 8 cases had bleeding and 5 cases had peritumoral edema. Anaplastic oligodendrogliomas(WHO Ⅲ grade) were found in 22 cases with a median age of 32 years. Most of the tumors occurred in cortex and medulla junction of frontal, parietal and temporal lobes, with clear boundary. On CT images, 10 cases was slightly low-density, 12 cases were mixed density. On T1WI, 19 cases were low signal and 3 cases were iso-intense. 19 patients showed high signal on T2WI. On enhanced CT scan, 2 cases showed mild enhancement and 20 cases showed significant enhancement. 3 cases had calcification; 12 cases had cystic necrosis; nine cases had hemorrhage and 22 cases had peritumoral edema. Conclusions: Cystic necrosis, hemorrhage, edema and enhancement were more common in anaplastic oligodendrogliomas(WHO Ⅲ grade) than in glioblastoma. These imaging features contribute to tumor classification before surgery, and treatment planning for the tumor.
2012, Vol. 23 
