Objective To investigate CT and MRI features of extragonadal primary seminoma and improve its diagnostic accuracy.Methods The clinical and imaging features of 8 patients with extragonadal primary seminoma proved by histopathology were analyzed retrospectively.Results In 8 cases,4 cases were located in intracranial regions,4 cases in the abdominal and pelvic cavity.Detailedly,roundlike solid and cystic tumors were seen in the basal ganglia and thalamus in 2 cases.The mass density and signal were inhomogeneous in the necrotic area with slight peritumoral edema and heterogeneous enhancement,and hemorrhage and metastasis of the third ventricle were occurred inone case.Shallow lobulated tumor was occurred in the pineal region forone case,which MRI features included slightly low signal on T1 WI,equal or higher signal on T2 WI,with obvious enhancement and peripheral cystic change.There was one case in the sella area with slight high density on CT routine scan,and on MRI,slight equal signal on T1 WI,equal or higher signal on T2 WI.The pituitary stalk was involved with thickening.Tumor in suprasellar region was obviously enhanced,with a small uniformity enhancement nodule in the mouth of corpus callosum.4 cases were occurred in the abdominal and pelvic cavity,shallow lobulated tumors with varying degrees of necrosis were found on CT with infiltrating growth and slight to moderate enhancement,and swollen lymph nodes were found in retroperitoneal and mesenteric root areas.Conclusion Extragonadal primary seminoma is rare,there are some characteristic imaging findings,which contributes to improve diagnosis accuracy when combining with clinical data.

Objective To quantitative analyze the injury degree of cervical cord in cervical spondylotic myelopathy (CSM) patients using fractional anisotropy (FA) entropy of diffusion tensor imaging (DTI).Methods Twenty-four CSM patients and well-match healthy volunteers underwent cervical cord DTI scanning.FA value was measured at each segment of spinal cord (including grey matter and white matter) of spinal cord level and intervertebral disc level.Further Shannon entropy of FA value was calculated in each segment to observe the disorder degree of cervical cord structure in CSM patients.After the analysis of homogeneity of variance,two samples t test analysis was used to identify FC's differences of FA and Shannon entropy of FA value between the two groups.Result In CSM group,the average FA value of whole cervical cord was 0.644 ± 0.056,while it was 0.672 ± 0.035 in the healthy control group.There was significant difference of FA values between the two groups (t=-2.049,P=0.046).The FA entropy of CSM patients' cervical cord was 0.687±0.043,while it was 0.854±0.027 in the healthy control group.The FA entropy of CSM patients' cervical cord was lower than that of control group.There was significant difference of FA entropy between the two groups (t=-12.100,P＜0.001).The significant difference between the two groups was only found at C6 level for each level's FA value.The FA entropy of CSM patients' cervical cord was significantly lower than that of control group for every level.Conclusion This decreased FA entropy of cervical cord in CSM patients indicates that FA entropy can be used to detect the disorder of cervical cord structure in CSM patients.

Objective To assess the altered regional homogeneity (ReHo) of local intrinsic cerebral activity within sensorimotor network(SMN) in patients with cervical spondylotic myelopathy (CSM) before or after spinal cord decompression using functional MRI (fMRI). Methods Twenty-one CSM patients who would decompress spinal canal, and 21 healthy volunteers (age, gender and level of education matched) were enrolled from June 2013 to April 2014. All the patients underwent rs-fMRI examination before and 3 months after spinal cord decompression. ReHo measurement was performed statistically within a SMN mask. A second-level random-effect 2-tailed Student's t test was applied to compare the ReHo results between pre-and post-operation CSM patients and healthy volunteers. A second-level paired 2-tailed Student's t test was applied to compare the ReHo results between pre-and post-operation CSM patients. Pearson correlation analysis was performed to assess the correlations between the altered ReHo and clinical evaluation. Results Compared with healthy volunteers, pre-operation patients showed significantly lower ReHo in the left postcentral gyrus/precentral gyrus, together with enhanced ReHo in the right superior parietal lobule (GRF correction, P<0.05). Post-operation CSM patients showed significantly lower ReHo in the right superior parietal lobule comparing with healthy volunteers, as well as enhanced ReHo in the left postcentral gyrus/precentral gyrus comparing with pre-operation (GRF correction, P<0.05). Abnormal ReHo areas in CSM patients demonstrated no significant correlation with clinical measurements (P>0.05) between pre-operation and post-operation. Conclusions Myelopathy in cervical cord may affect intrinsic cerebral activity, as patients with CSM show disrupted regional homogeneity within sensorimotor network. The change of ReHo following decompression suggests that central plasticity may influence functional recovery.

Objective To investigate the alterations of regional spontaneous activity in patients with classical trigeminal neuralgia (CTN) during resting state.Methods Twenty-seven patients with CTN (CTN group) and 27 healthy subjects (control group) were recruited and underwent a rest-state functional MRI.The regional homogeneity (ReHo) analysis was used to compare the differences of regional synchronization of spontaneous brain activity.And correlation tests were performed between ReHo values in the abnormal brain areas and clinical metrics (visual analogue scale and disease duration) of the disease.Results Compared with control group (P＜0.05,Gaussian random field correction),ReHo increased in bilateral primary somatosensory cortex (S1) and primary motor cortex (M1),right supplementary motor area (SMA),inferotemporal cortex and cerebellum,left thalamus,limbic lobe,parahippocampa gyrus,middle and superior temporal gyrus in CTN group;ReHo decreased in bilateral insula,prefrontal cortex and orbitofrontal cortex,right frontal medial cortex and superior temporal gyrus,left anterior cingulate area,supramarginal gyrus and cerebellum in CTN group.ReHo values in right frontal medial cortex was negatively correlated with the course of disease (r=-0.45,P=0.03).The ReHo values of left primary sensorimotor cortex were positively correlated with the visual analogue scale scores (r=0.46,P=0.02).Conclusion CTN patients has abnormal functional homogeneity of spontaneous brain activity in regions involved in the pain processing,which can help understanding mechanism of CTN.

Objective ToanalyzetheCTimagingfeaturesofatypicalpulmonaryhamartomas,soastounderstandthecausesof misdiagnosisandimprovetheaccuracyofdiagnosis.Methods 18caseswithatypicalpulmonaryhamartomasconfirmedbypathology inourhospitalwerecollectedretrospectively,including9 malesand9females.18caseswereexaminedbychestCTscans,among which,2caseswithplainscans,and16caseswithenhancedscans.TheresultsofCTimagingwereanalyzedbytwoassociatechief radiologistswithdoubleblindmethod,observingthelesionlocation,size,edge,border,density,enhancementfeatures,theremaining lungtissue,theageofonset,history,andclinicalmanifestations.Results Inall18cases,3caseswereendotracheallesion,ofwhich1 casewasinleftmainbronchus,theothertwowereinrightmiddleandupperbronchusrespectively,showingcalcificationdensityand subsequentatelectasis;15caseswereperipherallesions,including7casespresentingrightpulmonarynodulesand8casespresenting leftpulmonarynodules.Allperipheralcasesweresolitarypulmonarynoduleswithoutcalcificationandfatdensity.Thediameterof nodulesrangedfrom0.3cmto2.1cm.5casesshowedsmoothroundisolatednodulesand10casesshowedshallowlobulatednodules. In16casesofenhancedscan,1lesionshowedremarkableenhancement,6lesionsshowedslightlyenhancement,and9lesionsshowed nosignificantenhancement.Conclusion PulmonaryhamartomaislackofcharacteristicofCTimaging,whichisthemainreasonof misdiagnosis.Recognizingitsdiverseimageperformancesincludingshallowlobulation,roughedge,remarkableenhancementandetc. helpsusavoidmisdiagnosis.