Objective To study the imaging characteristics of intracranial dysembryoplastic neuroepithelial tumors(DNT),and to evaluate the role of CT and MRI in their diagnosis.Methods We presented 8 DNTs cases confirmed histopathologically after operation.CT and MRI features were retrospectively analyzed(3 cases received MR scan only and 5 had both studies),compared with the surgical findings and pathological appearance.Results Eight patients had totally 11 tumors with multifoci in 2 cases.Six DNTs were located in the temporal lobe,1 lesion involved the parietal lobe,1 in the frontal lobe,1 in the brain stem,1 in the cerebellum,and 1 in the frontal and temporal lobe simultaneously.All lesions were observed intracortically,and partial of them extended into the subcortical location.On 5 non-contrast CT scans,3 DNTs were homogeneously hypodense;1 case contained isodense nodules within the hypodense focus.Peripheral spotty calcification was found in 1 case.On pre-contrast MR images,all lesions showed hypointense on T_1-weighted images,moreover,multicystic change with more markedly decreased signal intensity was observed.The DNT had a well-demarcated,multinodular gyriform configuration,or a soap bubble appearance at the cortical margin.On T_2-weighted images,high signal intensity of the tumors was seen except for hypointense calcification.The bone remodeling of the adjacent calvaria was noticed in(1 case.) The tumors had slightly increased signal intensity on FLAIR(fluid attenuated inversion recovery) in 2 cases,and homogeneously mild hyperintense on PDW(proton density weighted imaging),while the isointense focus was observed in one case on DWI(diffusion weighted imaging).No obvious enhancement was identified except 1 lesion with mild enhancement following intravenous administration of contrast material.3 tumors had ill-defined contours,whereas the others showed well-demarcated margins.No surrounding vasogenic edema was present except 2 foci with slight edema.Conclusion DNT usually shows characteristic radiologic findings,in combination with the clinical presentation and history,the diagnostic accuracy should be improved,and,as such,unnecessary radiation and/or chemotherapy may be avoided.

The authors described the attempt of general practice in hierarchical medical system aided by the medical service partnership model.This reform has achieved an effective and efficient hierarchical medical system for chronic diseases within a medical alliance, overcoming the existing hierarchical medical system centering on a hospital.Other merits of the reform include a general practice guidance pattern between general hospitals and community hospitals and enhanced general practitioner competence in communities,effectively encouraging general practice progress.