Independent Component Analysis and Graph Theoretical Analysis in Patients with Narcolepsy / 神经科学通报·英文版

The present study was aimed to evaluate resting-state functional connectivity and topological properties of brain networks in narcolepsy patients compared with healthy controls. Resting-state fMRI was performed in 26 adult narcolepsy patients and 30 matched healthy controls. MRI data were first analyzed by group independent component analysis, then a graph theoretical method was applied to evaluate the topological properties in the whole brain. Small-world network parameters and nodal topological properties were measured. Altered topological properties in brain areas between groups were selected as region-of-interest seeds, then the functional connectivity among these seeds was compared between groups. Partial correlation analysis was performed to evaluate the relationship between the severity of sleepiness and functional connectivity or topological properties in the narcolepsy patients. Twenty-one independent components out of 48 were obtained. Compared with healthy controls, the narcolepsy patients exhibited significantly decreased functional connectivity within the executive and salience networks, along with increased functional connectivity in the bilateral frontal lobes within the executive network. There were no differences in small-world network properties between patients and controls. The altered brain areas in nodal topological properties between groups were mainly in the inferior frontal cortex, basal ganglia, anterior cingulate, sensory cortex, supplementary motor cortex, and visual cortex. In the partial correlation analysis, nodal topological properties in the putamen, anterior cingulate, and sensory cortex as well as functional connectivity between these regions were correlated with the severity of sleepiness (sleep latency, REM sleep latency, and Epworth sleepiness score) among narcolepsy patients. Altered connectivity within the executive and salience networks was found in narcolepsy patients. Functional connection changes between the left frontal cortex and left caudate nucleus may be one of the parameters describing the severity of narcolepsy. Changes in the nodal topological properties in the left putamen and left posterior cingulate, changes in functional connectivity between the left supplementary motor area and right occipital as well as in functional connectivity between the left anterior cingulate gyrus and bilateral postcentral gyrus can be considered as a specific indicator for evaluating the severity of narcolepsy.

Correlation study of MRI features and pathological typing in focal cortical dysplasia / 实用放射学杂志

Objective To explore the correlations of the MRI findings and its pathological typing in the focal cortical dysplasia (FCD) .Methods MR images of 74 patients with FCD confirmed by operation and histopathologic examination were analysed retro‐spectively .MRI findings with FCD were divided into three subtypes including radial band type ,hyperintensity type and mild type . The correlation of the FCD MRI findings and pathological typing is analysed .Results In 74 patients with FCD ,there were radial band type in 12 cases ,hyperintensity type in 32 cases ,and mild type in 30 cases respectively .M RI finding of radial band type FCD showed a tail of increased T2WI/FLAIR signal tapering down to the lateral ventricle .Hyperintensity type FCD showed increased T2 WI/FLAIR signal in the cortex and subcortical white matter ,accompanied with focal cortical thickening .Mild type FCD showed T2 WI/FLAIR subtle hyperintense signal in cortex with or without focal cortical thickening ,but there was no hyperintense signal in subcortical white matter .Most of radial band type FCD were ⅡB in pathology .Most of hyperintensity FCD were ⅡA and ⅡB .Mild type FCD was more found to beⅠA orⅠB .Conclusion Analysing MRI features would improve the accurate diagnosis of FCD and help to infer the pathological type .

MRI features and pathologic types of benign meningiomas and their correlation with tumor recurrence / 中华放射学杂志

Objective To determine MR manifestations and pathologic types of benign meningiomas and their relationship with tumor recurrence.Methods There were 218 patients (160 females,58 males; age range 4-79 years) with benign meningiomas in the study,including 31 recurrent meningiomas (recurrence group)and 187 primary meningiomas (primary group).All patients were proved by postoperative pathology.Differences of pathological types and MRI manifestations between the recurrence group and the primary group were evaluated by using x2 test and rank sum test.Logistic regression analysis was performed by taking tumor recurrence as the dependent variable,and age,gender,vital structures involvement and pathologic types as independent variables.The recurrent time intervals were compared by rank sum test.Results There were 30 patients with intracranial vital structures involvement or extreintracranial communication tumors in the recurrent group,which was obviously higher than that of the primary group (61 patients).The difference was statistically significant (x2 =57.672,P =0.001).The tumors located in the skull-base and juxtasinus in the recurrent group were obviously more than those in the primary group,and difference was statistically significant (x2 =10.990,P =0.001).Multi-logistic regression analysis showed that the recurrent risk of benign meningiomas was elevated significantly only with vital structure involvement or extre-intracranial communication tumors (wald x2 =31.863,OR =3.820,P =0.001).The recurrent risk of dural sinus involvement was 3.820 times of cerebral artery trunk and cranial nerves involvement,and the risk of the latter was 3.820 times of the non-involved.There was no statistical difference between the two groups in pathology type,location,peritumoral edema,tumor morphology and tumor size.The relapse time of dural sinus involvement and cerebral artery trunk involvement in the recurrent group was 24(13 to 180) and 126(12 to 187) months,respectively.There was significant difference (Z =2.197,P =0.028).Conclusions It is more common that the recurrent benign meningiomas located in the skull base and juxtasinus.The recurrent risk significantly increases when benign meningiomas with vital intracranial structure involved or with extra-intracranial communication tumor.The relapse time of dural sinus involvement is possibly shorter than that of cerebral artery trunk involvement.MRI plays an important role in predicting tumor recurrence and prognosis of benign meningiomas.

MRI diagnosis of Rasmussen encephalitis / 中华放射学杂志

ObjectiveTo describe the MR features of Rasmussen encephalitis (RE).Methods The MRI of 10 pathologic confirmed patients (7 male,3 female,mean age 11 ± 4 years) with RE were retrospectively analyzed in this study.Routine axial,sagittal and coronal (perpendicular to the oblique long axis of the hippocampus) scans were obtained for T1WI,T2WI and fluid-attenuated inversion recovery (FLAIR)images. The location and degree of cerebral atrophy,gray matter signal changes,and the evolution of these findings were evaluated. Results Brain atrophy included the enlargement of lateral ventricle(8/10),temporal horn (9/10)and lateral fissure (9/10); widened sulci and small gyri in the isolateral hemisphere (7/10) ; atrophy in caudate and putamen nucleus (6/10).The cortical atrophy was extensive at late stage of the RE,and usually was hemispheric or involved more than two lobes.The signal changes included hyperintensity involving extensive cortical and/or subcortical regions (9/10). The follow-up MR study demonstrated the progression of brain atrophy and extensive signal changes.Conclusions RE usually presents in pediatric patients. The imaging findings included progressive unilateral brain atrophy,enlargement of lateral ventricle,lateral fissure and sulci,and small gyri with or without cortical T2hyperintensity.Deep nucleus atrophy may be involved in RE.