Objective To evaluate the fiber altering and clinical relationship in patients with occipital and temporal lobe cerebral infarction with DTI.Methods Fifty patients suffering from cerebral stroke were analyzed with conventional MRI,DWI and DTI. The fibers of visual pathway were depicted ,and their fractional anisotropy (FA),apparent diffusion coefficient (ADC),isotropic im-age (Iso)and T2-weighted trace were measured and analyzed.Results Regions of interest (ROIs)were placed in infarction and nor-mal contralateral tissue for tracking the visual pathways.The different parameters were measured.FA is useful to differentiate hy-per-acute stroke from acute and sub-acute stroke.FA values increased slightly in hyper-acute and decreased in acute,sub-acute and chronic phase.The values of ADC in infarction regions in hyper-acute,acute and sub-acute phases were lower than those of the con-tralateral tissue.Iso and T2-weighted trace increased in acute phase and decreased in chronic phase.DTT was used to show the way and chang of visual pathway.Conclusion DTI could track the fiber of visual pathway,and depict the fiber of infarction zone.DTT could be used in evaluating the prognosis of patients.

Purpose To explore the value of 320 row dynamic volume CT angiography in the preoperative assessment of juvenile nasopharyngeal angiofibroma (JNA) and in determining feeding arteries.Materials and Methods The imaging data of 18 cases with JNA proved by surgery and pathology and examined by 320 row dynamic volume CT were analyzed retrospectively.The imaging staging and feeding artery of tumors were determined.Results Most tumors (17/18) showed heterogeneous enhancement in the early stage of enhancement.With the extension of time,the enhancement scope of lesions expended.The time-density curve (TDC) of 11 cases demonstrated rapid ascending and rapid descending after injecting contrast,while 7 cases showed continuous increasing.The blood supply of all tumors included the external carotid artery system of the affected side and showed a close relationship with tumor staging.With the increase of tumor stage,the number of feeding arteries increased (r=0.858,P＜0.05).The feeding arteries of stage Ⅱc and stage Ⅲ tumors included ipsilateral maxillary artery and ascending pharyngeal artery.Besides,the effective radiation dose of 320 row CT angiography for searching arteries [(3.30±0.08) mSv]was less than that of DSA [(7.62±2.39) mSv] (t=-7.98,P＜0.05).Conclusion The 320 row dynamic volume CT imaging of JNA has certain characteristics,which can display the blood supply artery and accurate staging of tumors,thus it has important value in preoperative evaluation of JNA.

Since the global COVID-19 pandemic, SARS-CoV-2 infection, which causes COVID-19, has been associated with a range of diseases whose atypical manifestations have been increasingly reported. The mild encephalitis or encephalopathy associated with reversible corpus callosum lesions or mild encephalitis/encephalopathy with reversible splenial lesion (MERS) is a rare clinical and radiographic syndrome. At present, the pathogenesis of MERS caused by COVID-19 is still unclear, and its pathogenesis may include hypoxic damage, inflammatory response, immune disorders, changes in osmotic pressure, excitatory amino acid toxicity, oxidative stress and functional abnormalities of renin-angiotensin system. This paper reports a case of severe COVID-19 complicated with MERS, and discusses the pathogenesis from a pathophysiological point of view.