Differential Diagnosis Of Brain Tumors And Non-neoplastic Diseases Which Manifested As Local Hypodensity On Precontrast Ct: A Primitive Study With CTP

Part one Differential diagnosis of brain tumors and non-neoplastic diseases which manifested as local hypodensity on precontrast CT:a primitive study with CTPObjective:To probe the value of CT perfusion (CTP) in differentiating of brain tumors and non-neoplastic lesions which meanifested as local hypoattenuation on precontrast CT.Methods:28 cases of brain tumors and 29 cases of non-neoplastic diseases,which diagnosis confirmed by surgery and folloup,were inclued.Brain tumor group included 13 cases with low-grade astrocytoma ( 2 cases with grade I, 11 cases with grade II),7 cases with high-grade astrocytoma (2 cases with III grade, 5 cases with IV grade),6 cases with metastatses,2 cases with lymphoma.Non-neoplastic disease group included 19 cases with cerebral infarctions,3 cases with multiple sclerosis,7 cases with malcia after radiotherapy and injury.All patients underwent pre- and post contrast CT and CTP examinations.Cerebral blood flow(CBF), cerebral blood volume(CBV), mean transit time (MTT) and cerebral vascular permeability surface(PS) values were measured.The difference of CT perfusion parameters of brain tumors group and non-neoplastic diseases group,and the accuracy of CTP and postcontrats CT were analyzed with rank sum test and Chi-square test separately.Result:The value (median,interquartile range) of CBF,CBV,MTT and PS of brain tumors and non-neoplastic diseases were (35.00 ml·min~-1·100g~-1,38.60 ) and (10.15 ml·min~-1·100g~-1,9.44),(3.05 ml·100g~-1,2.83) and (0.91 ml·100g~-1,0.53),(3.82 ml·min~-1·100g~-1,7.96) and (0.38ml·min~-1·100g~-1,0.63) respectively. Significant difference waas found for CBF,CBV and PS of two groups (P<0.05).Whereas there was was no obvious differences for MTT (P>0.05).The accuracy of discriminating between brain tumor and non-neoplastic diseases with enhanced CT and CTP were 75% and 53% respectively (P<0.05).Histologically, scattered tumor cells and angiogenesis with varying degrees could be detected for astrocytoma, tumor cells and vascular structures similar with primary leisons for metastases, tumor cells arranged about the vascular space as"sleeve"for lymphoma. In non-neoplastic group, swelling neuroglia cells and part of them broken were found forcerebral infarctions, demyelination and inflammatory cytokines surrounding vascular for multiple sclerosis.Conclusion:Significant difference was found of CBF,CBV,and MTT between brain tumors group and non-neoplastic diseases group Their pathological bases of two groups were different.Higher accuracy of CTP for dixcriminating was concluded then.The CTP parameters will play certain role in differentiating brain tumors and non-neoplastic lesions which manifested as local hypodensity.Part two The value of CTP in the differential diagnosis between diffuse astrocytomas and cerebral infarctionsObjective : To explore the value of CT perfusion parameters in distinguishing diffuse astrocytomas from cerebral infarction.Methods:13 cases with diffuse astrocytomas and 19 cases with cerebral infarctions(7 cases in acute stage and 12 cases in subacute stage) were included in this study. All patients underwent conventional CT, enhanced CT and CTP examination.The CT perfusion parameters,including cerebral blood flow(CBF), cerebral blood volume(CBV), mean transit time (MTT) and permeability surface(PS) values were measured.The difference of CTP parameters of the two entities was evaluated with independent samples t test and rank sum test.Results: CBF,CBV,MTT and PS value of diffuse astrocytomas and cerebral infarctions were 28.07±6.93ml·min~-1·100g~-1 and 8.71±5.43 ml·min~-1·100g~-1,1.85±0.77ml·100g~-1 and 0.85±0.47ml·100g~-1,6.08±2.23s and 14.16±5.62s,(1.73,2.23)ml·min~-1·100g~-1 and (0.91,1.46)ml·min~-1·100g~-1 respectively.Significant difference was found for CBF,CBV,MTT between two entities(P<0.05).Whereas therewas no significant difference of PS between them(P>0.05).Histologically, a few neoplastic cells and hyperplastic vascular structures were detected for diffuse astrocytoma.But there were swelling neuroglia cells and edema for 2 cases with cerebral infarction.Conclusion:The values of CBF,CBV,MTT of diffuse astrocytomas and cerebral infarctions were different prominently for their different pathological bases.CTP examination may be helpful for their differential diagnosis.