Cortical hierarchy disorganization in major depressive disorder and its association with suicidality.

Objectives: To explore the suicide risk-specific disruption of cortical hierarchy in major depressive disorder (MDD) patients with diverse suicide risks. Methods: Ninety-two MDD patients with diverse suicide risks and 38 matched controls underwent resting-state functional MRI. Connectome gradient analysis and stepwise functional connectivity (SFC) analysis were used to characterize the suicide risk-specific alterations of cortical hierarchy in MDD patients. Results: Relative to controls, patients with suicide attempts (SA) had a prominent compression from the sensorimotor system; patients with suicide ideations (SI) had a prominent compression from the higher-level systems; non-suicide patients had a compression from both the sensorimotor system and higher-level systems, although it was less prominent relative to SA and SI patients. SFC analysis further validated this depolarization phenomenon. Conclusion: This study revealed MDD patients had suicide risk-specific disruptions of cortical hierarchy, which advance our understanding of the neuromechanisms of suicidality in MDD patients.

Aberrant Inter-hemispheric Connectivity in Patients With Recurrent Major Depressive Disorder: A Multimodal MRI Study.

Objective: Inter-hemispheric network dysconnectivity has been well-documented in patients with recurrent major depressive disorder (MDD). However, it has remained unclear how structural networks between bilateral hemispheres relate to inter-hemispheric functional dysconnectivity and depression severity in MDD. Our study attempted to investigate the alterations in corpus callosum macrostructural and microstructural as well as inter-hemispheric homotopic functional connectivity (FC) in patients with recurrent MDD and to determine how these alterations are related with depressive severity. Materials and Methods: Resting-state functional MRI (fMRI), T1WI anatomical images and diffusion tensor MRI of the whole brain were performed in 140 MDD patients and 44 normal controls matched for age, sex, years of education. We analyzed the macrostructural and microstructural integrity as well as voxel-mirrored homotopic functional connectivity (VMHC) of corpus callosum (CC) and its five subregion. Two-sample t-test was used to investigate the differences between the two groups. Significant subregional metrics were correlated with depression severity by spearman's correlation analysis, respectively. Results: Compared with control subjects, MDD patients had significantly attenuated inter-hemispheric homotopic FC in the bilateral medial prefrontal cortex, and impaired anterior CC microstructural integrity (each comparison had a corrected P < 0.05), whereas CC macrostructural measurements remained stable. In addition, disruption of anterior CC microstructural integrity correlated with a reduction in FC in the bilateral medial prefrontal cortex, which correlated with depression severity in MDD patients. Furthermore, disruption of anterior CC integrity exerted an indirect influence on depression severity in MDD patients through an impairment of inter-hemispheric homotopic FC. Conclusion: These findings may help to advance our understanding of the neurobiological basis of depression by identifying region-specific interhemispheric dysconnectivity.

An aberrant hippocampal subregional network, rather than structure, characterizes major depressive disorder.

BACKGROUND: Behavioral and neuroimaging studies have implicated the hippocampus as a cardinal neural structure in major depressive disorder (MDD) pathogenesis. The hippocampal subregion-specific structural and functional abnormalities in MDD remain unknown. METHODS: Multimodal magnetic resonance imaging (MRI) was acquired in 140 patients with MDD and 44 age- and sex-matched healthy controls (HCs). We quantified hippocampal subregional volumes and fractional anisotropy (FA) following a structural and diffusion MRI data analysis processing stream. Hippocampal subregional networks were established using seed-based functional connectivity (FC) analysis. Univariate analysis was used to investigate the differences between the two groups. Significant subfield metrics were correlated with depression severity. RESULTS: Compared with HCs, we did not find significant differences in subregional volumes or FA metrics in the MDD group. The MDD group exhibited a significantly weaker connectivity of the right hippocampal subregional networks with the temporal cortex (extending to the insula) and basal ganglia but showed increased connectivity of the right subiculum to the bilateral lingual gyrus. The FC between the right cornu ammonis 1 and right fusiform, between the right hippocampal amygdala transition area and the bilateral basal ganglia, were negatively correlated with depression severity (r = -0.224, p = 0.010; r = -0.196, p = 0.025, respectively) in the MDD group. LIMITATIONS: This study did not consider the longitudinal changes in the structure and functional connectivity of the hippocampal subregion. CONCLUSION: These findings advance our understanding of the neurobiological basis of depression by identifying the hippocampal subregional structural and functional abnormalities.

MRIandpathologicfindingsofintracranialsolitaryfibroustumor/hemangiopericytoma / 实用放射学杂志

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.

MSCT features of gastric schwannoma and misdiagnosis analysis / 实用放射学杂志

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.

Noninvasive assessment of hepatic fibrosis staging with MR elastography versus T1ρ imaging / 中华放射学杂志

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.