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Objective To verify the feasibility of a rat model of acute hypertension, and to observe the imaging findings at 7.0T MR scanner of the model.Methods In experimental group, the rats were scanned at 7.0T Bruker MR scanner when phenylephrine was injected continuously to evoke an acute hypertension state.The real time blood pressure was monitored through a femoral arterial catheter connected to a pressure transducer.The control group was infused with saline.T2WI, DWI and T1 mapping were performed in the two rat groups.ADC maps and T1 maps were acquired after image post-processing, and a voxel wise analysis and a ROI analysis were applied.The brain morphology change was evaluated by HE staining.The blood-brain barrier permeability was evaluated by Evans blue staining.Results The T2 images and DWI images of the experiment group showed no abnormal signal intensity changes observed by naked eyes.But ROI analysis of the ADC maps showed that the brain ADC values of the experiment group was higher than the control group (t=3.291,P0.05).The blue dye region was only performed in the experimental group,the results of HE staining corresponded with vasogenic brain edema.Conclusion Continuous infusing of phenylephrine hydrochloride can induce a rat model of acute hypertension.Vasogenic edema and blood-brain barrier permeability change can be observed in the rat model, and the imaging distribution of vasogenic edema can be detected by MRI.
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Objective To analyze the clinical and MRI manifestations of neurosyphilis in order to improve the recognition and di‐agnosis of the disease .Methods The MRI and clinical data of 11 patients with neurosyphilis confirmed in clinic were collected .The patients were categorized into different phenotypic types according to the clinical manifestations ,and the MRI manifestations were al‐so analyzed .Results 5 patients with parenchymal types showed cerebral atrophy .3 patients with meningovascular types showed cer‐ebral infarction .1 patient with encephalitis showed brain signal changes and meningeal enhancement .1 patient without symptom showed signal changes in brain parenchyma and mild enhancement .1 patient of myelopathic type showed signal changes of thoracic spinal cord without enhancement .Conclusion There is an overlap of the MRI findings of neurosyphilis in different clinical pheno‐types ,exhibiting no specifity .Neurosyphilis can be diagnosed when the young patient is manifested as cerebral atrophy ,infarction , MR signal intensity abnormality of cerebral parenchyma and spinal cord ,as well as meningeal enhancement .
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Objective To investigate the clinical and MRI features and pathogenic mechanism of posterior reversible encephalopathy syndrome (PRES) in patients with systemic lupus erythematosus (SLE).Methods Six cases of PRES in SLE proved by integrated clinical diagnosis were collected from January 2008 to December 2013.The clinical and MRI features of these patients were studied retrospectively and the related literatures were reviewed.Results The initial episode of nervous system was involved in 4 cases.The clinical presentations were headache (2 cases),seizures (4 cases),acute confusion state (2 cases),altered mentation (1 case) and vision change (1 case).All cases had lupus nephritis and hypertension,in which 4 cases had renal failure;6 cases were treated with immunosuppressive agents and 4 cases with cyclophosphamide for lupus nephritis when they developed PRES.The vasogenic edema lesions were distributed in the parietal or occipital lobe (5 cases),the frontal lobe (4 cases),temporal lobe (4 cases),basal ganglia (3 cases),splenium (1 case) and cerebellar hemispheres (2 cases).Three major patterns of PRES included dominant parietal-occipital (2 cases),the holohemispheric watershed (3 cases),and superior frontal sulcal (1 case).Conclusions The clinical and MRI findings of PRES in patients with SLE are typical.Awareness of this entity as early as possible can help to improve curative effect and prognosis.
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Objective To explore the value of diffusion tensor tractography (DTT)in grading gliomas.Methods 27 patients with brain glioma(gradeⅠ-Ⅱ in 1 1 cases and grade Ⅲ-Ⅳ in 1 6 cases)confirmed by pathology were collected.Conventional MR and DTT were carried out and the bilateral corticospinal tracts(CST)were reconstructed before operation.The fiber density index (FDi)and relative FDi (rFDi= ipsilateral FDi/contralateral FDi)of CST was measured.Results The FDi of ipsilateral CST was lower than that of the contralateral CST in all patients(P 0.05).The rFDi of LGG was higher than that of HGG (P <0.05).Conclusion In com-bination with conventional MR,DTT can improve the accuracy of grading gliomas.