CT And MRI Features Of Ependymal Tumors In The Central Nervous System Of Children

PartⅠCT and MRI features of supratentorial anaplastic ependymomas in childrenObjective: To analyze the CT and MRI features of imaging of pediatric supratentorial anaplastic ependymomas.Material and methods: Between 2012 and 2017,clinical information and image findings from 13 children with pathology-confirmed naplastic ependymomas were retrospectively reviewed.The mean ADC value,minimum ADC value and tumor/nomal brain ADC ratios(r ADC)of the solid component of the tumors were measured,and metabolites were observed.All patients underwent MRI scans before operation,7 patients underwent 1H-MRS scans,11 patients also underwent CT scans before MRI scans.Results: 1 case located at the third ventricle,12 tumors located at the parenchyma(11 tumors located at right parenchyma,1 tumor located at left parenchyma)which volume were more bigger.On CT plain scan,the solid component of 5 cases appeared as isodensity,and 6 cases showed hyperdensity.9 cases showed calcification and 6 cases had speckled calcification.All cases were cystic solid tumors,11 cases showed huge cystic degeneration,2 cases showed multiple microcystic degeneration.9 tumors appeared as cystic component closed to the lateral ventricle and 7 tumors solid component located at cortex.3 cases showed no peritumoural edema,8 cases appeared mild peritumoural edema,and 2 cases presented moderate peritumoural edema.The solid component of the tumors appeared as iso-hypointensity on T1 WI,and iso-hyperintensity on T2 WI.All tumors showed obvious enhancement,with 12 cases appeared as ring like enhancement,1 case showed heterogenous enhancement accompanyied with nodular enhancement.12 cases showed slightly hyperintense on DWI,1 case presented isointense.The meanADC values(ADCmean)was(0.757±0.149)×10-3mm2/s,the minimum ADC values(ADCmin)was(0.601±0.114)×10-3mm2/s,and the tumor/normal brain ADC ratios(r ADC)was(0.867±0.185)×10-3mm2/s.On 1H-MRS,all tumors showed choline(Cho)increased,N-acetylaspartate(NAA)decreased,only 2 caseas showed lipid increased,none case showed m I increased.Conclusion: The CT and MRI manifestation of supratentorial anaplastic ependmoma in children have specific features,which can be helpful in the diagnosis.Part ⅡThe correlated analysis of imaging findings and pathology of pediatric ependymal tumoursObjective: To analyze MRI and CT features of pediatric ependymal tumours and compared with the pathological classificationMaterial and methods: Between 2012 and 2017,clinical information and imaging features from 57 patients with pathology confirmed were retrospectively reviewed.1 case located at the spinal canal.56 cases of intracranial tumors were divided into WHO Ⅱ(15/56),WHO Ⅱ-Ⅲ(16/56),WHO Ⅲ(25/56).The location,density and signal characteristics,cystic degeneration,calcification,peritumoral edema,and strengthening methods were observed.The mean ADC value,minimum ADC value,tumor/nomal brain ADC ratios(r ADC)and metabolisms level were measured.Results: Of 57 cases of ependyma tumor in children,40 cases(70.2%)were located below the screen,16(28.1%)located on the supratentorial and 1(1.7%)in the spinal canal.Conventional imaging manifestations including T1 and T2 signal intensities,density,calcification,ring-like enhancement,cystic degeneration,and peritumoral edema were not significantly different among all histologic subtypes(P>0.05).There were no significant differences in ADCmean between each group(P>0.05).The ADCmin of grade WHO Ⅲ was lower than that of grade WHO Ⅱ(P<0.05).But there was no statistical significance in ADCmin between grade WHO Ⅱ and WHO Ⅱ-Ⅲ,WHO Ⅲ and WHO Ⅱ-Ⅲ.The r ADC of grade WHO Ⅲ was lower than that of grade WHO Ⅱ,WHO Ⅱ-Ⅲ(P<0.05).But there was no statistical significance in r ADC between grade WHO Ⅱ and WHO Ⅱ-Ⅲ,.On 1H-MRS,even the presence rate of lipid of each group were 50%,55.6% and 70%,the ratios of N-acetylaspartate(NAA)/ creatine(Cr),the ratios of choline(Cho)/ Cr,NAA/Cho,myo-inositol(m I)/Cr and the presence of lipid were not significantly different among all histologic subtypes(all P>0.05).Conclusion: CT and conventional MRI features,ADCmean,metabolite ratios and presence of lipid are not significantly different among different pathological types of ependymal tumors in children.The ADCmin and r ADC varied significantly and are helpful in differential diagnosis of pathological types of ependymal tumors,and can improve the preoperative diagnostic coincidence rate.