ABSTRACT
Objective Toinvestigatethecharacteristicsofclinicalpathologyand MRIofintracranialsolitaryfibroustumor/hemangiopericytoma (SFT/HPC).Methods ThisstudyanalyzedtheMRIimages,pathologicalandclinicaldataof14SFT/HPCpatientsretrospectively. AllthecasesweresubjectedtoMRIplainscanandenhancementexamination.CharacteristicsofMRIofallcaseswerereviewedtogetherwith clinicopathologicchanges.Results AllSFT/HPClesionswerelocatedintheintracranialbutextra-cerebralspace.6werelocatedabovethe tentoriumofcerebellum,and2werelocatedbelowit.Lesionsof6patientswereacrossthetentoriumofcerebellumandspreadfrom supratentorialtosubtenorialspace.Amongalllesions,4wereroundinshape,10werelobulated,and3weresmallnodulesaroundthe edge.9ofthemexhibitednecrosisandcysticstructures.11lesionsshowedhypointensityand3casesshowedisointensityonT1WI.All thelesionswereheterogeneoushyperintensetyonT2WI,and5ofthemdisplayed"yin-yang"patternonT2WI.11casesexhibitededema.Signalof vascularvoidflow wasobservedin6cases.Thesolidpartsofthetumorsshowedsignificanthomogeneousenhancementon MRI. StrongpositiveSTAT6stainingwasobservedforthenuclearoftumorcells.Conclusion ItisdifficulttodifferentiateSFT/HPCfrom meningeoma.The"yin-yang"patternonT2WIisthecharacteristicofSFT/HPC.Inaddition,nuclearpositivestainingofSTAT6isalsospecific featureofSFT/HPCcell.
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Objective To explore the MSCT features,diagnostic values and the misdiagnosis causes of gastric schwannomas.Methods T he CT images,pathological and clinical data of 9 misdiagnosis cases of gastric schwannomas were analyzed retrospectively,which were later confirmed by the operation and pathology.The study examined the CT findings in the following aspects:the lesion location, size,contour,border,growth pattern,enhanced pattern,hemorrhage,necrosis,calcification,and the presence and absence of perirenal lymph nodes.Results The gastric schwannomas were ovoid or round,with well-defined boundaries.Tumors were found in the gastric body in 6 cases(4 cases in the large gastric curvature and 2 in the small gastric curvature),the gastric antrum in 2 cases and the gastric fundus in 1 case.The largest lesion diameters ranged from 2.5 to 7.4 cm,with an average diameter of 3.2 cm.Extracavitary growth was found in 2 cases,intracavitary growth in 2 cases and both intracavitary and extracavitary growth in 5 cases.The density of the tumor was low and evenly distributed,without cystic change,necrosis or calcification.2 cases were found to have ulcer formation. Another 2 cases were found to have enlarged lymph nodes,which were pathologically confirmed to be reactive hyperplasia.In the CT contrast enhancement,mild homogeneous enhancement was found in 4 cases in the arterial phase,but no obvious enhancement was found in the other 5 cases.In the venous phase,all the cases were found to have moderate homogeneous enhancement.4 cases were found to have further enhancement in the delay phase.Conclusion The gastric schwannomas appears to be homogeneous soft tissue mass on the MSCT,with clear boundaries and low-density and without hemorrhagic necrosis or cystic lesions.MSCT examination can help to locate and characterize gastric schwannomas,and to observe the relationship between the tumor and the surrounding tissue structure.
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Objective To compare the diagnostic values of magnetic resonance elastography (MRE) and T1ρ imaging in staging hepatic fibrosis (HF) in a rabbit model.Methods The institutional animal care and use committee approved all experiments.Sixty healthy rabbits were divided into HF group (n=44) and control group (n=16).Each eight rabbits in the HF group and 4 rabbits in the control group were randomly selected at the 4th,5th,6th week and the remaining rabbits at the 10th week after subcutaneous injection with 0.1 ml 50％ CCl4 oily solution per kilogram of body respectively,to undergo liver MR scan including axial liver MRE and T1ρ imaging.The values of liver stiffness (LS) and T1ρ were measured.Masson trichrome staining of liver tissue was used.According to the Scheuer scoring system,rabbits were classified into F0 to F4 group based on the percentage of hepatic fibrosis.The difference of LS values and Tip values among stage F0 to F4 were compared by the one-way ANOVA analysis.The correlations between pathological staging and LS,T1ρ values were performed by the Spearman correlation analysis.ROC curve analysis was performed to compare the value of MRE with T1ρ imaging.Results Forty three rabbits were included,there were 10,8,8,8,9 rabbits in F0,F1,F2,F3 and F4 stage,respectively.LS values were (1.051±0.155),(1.335±0.235),(1.401±0.163),(2.001±0.499) and (2.981±0.714) kPa in F0,F1,F2,F3 and F4,respectively,while T1 p values were (23.20±4.02),(24.28±2.93),(25.40± 1.82),(24.69± 1.85) and (31.54±3.39) ms (all P＜0.05).The correlation of LS values with hepatic fibrosis staging measured on MRE was stronger than T19 values (r values were 0.916 and 0.608,all P＜0.01).Area under ROC curve of LS value for differentiating hepatic fibrosis stage were 0.938 to 0.989,while the areas of T1ρ were 0.771 to 0.954.Conclusion MR elastography is an accurate technique for quantitatively staging hepatic fibrosis and superior to T1ρ imaging.