Gray Density Research Articles

Comparing call-playback to an observation-only method to survey Grey Partridge Perdix perdix on hill farms in northern England

ABSTRACTCapsule: Call-playback in spring can be a practical method to survey Grey Partridges Perdix perdix in rough grasslands with abundant cover. However, further research is required to investigate movements and other responses to call-playback.Aims: To compare call-playback with an observation-only method to survey Grey Partridges in rough grasslands with abundant cover, and to undertake a pilot study to consider whether bird behaviour conforms to point distance sampling assumptions.Methods: Grey Partridges were surveyed using two separate methods: call-playback and observation-only, at 10 equally spaced points along 14 independent 4 km routes at 3 study sites in northern England. Surveys were undertaken at dawn and dusk in spring (March and April) and again in summer (August and September).Results: In spring, call-playback registered at dusk fourfold and at dawn almost twice as many Grey Partridge encounters as the observation-only method. Methods did not differ in summer. In spring, using call-playback registered three times more encounters in rough grasslands with tall, dense cover than the observation-only method. Methods did not differ in summer. Grey Partridge encounter density estimates did not differ significantly between methods or seasons.Conclusion: Using call-playback in spring increased the numbers of Grey Partridge encounters and can be a practical survey method, but further research is required to compare results against known populations and to investigate movements and other responses to call-playback, which may violate distance sampling assumptions.

F172. INDIVIDUAL PREDICTION OF RISK IN ADOLESCENT OFFSPRING OF PARENTS WITH SCHIZOPHRENIA OR BIPOLAR DISORDER: A MACHINE LEARNING NEUROIMAGING STUDY WITH A CROSS-STAGE VALIDATION

BackgroundSchizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders that are not easily distinguishable based on clinical measures. Offspring of patients with SZ or BD have a tenfold increased risk of developing the disorder as well as an increased risk for other severe mental disorders. Reliable identification of these subjects might allow for early recognition and intervention, which have been shown to be beneficial for treatment outcome and may even prevent transition to illness. Based on abundant evidence that SZ and BD are associated with structural brain abnormalities, we investigated whether MRI brain-scans can be used to detect individual risk of developing SZ or BD in adolescents.MethodsStructural MRI brain-scans were acquired in adolescent offspring (8–19 year) of parents with schizophrenia (oSZ;N=50), bipolar disorder (oBD;N=82), and without a mood or psychotic DSM-IV disorder (oHC;N=53), as part of the Dutch Bipolar and Schizophrenia Offspring Study (DBSOS). Support vector machine (SVM) models were trained on the gray matter tissue density maps to predict to which offspring class (oHC/oBD/oSZ) an individual belonged. Prediction accuracy was assessed using cross-validation. To validate our prediction models, we applied them to the tissue maps from subjects from a sample of unrelated HC/BD/SZ adults. Secondly, validated prediction models built from the adult subjects’ MRI scans were applied to the tissue maps of the adolescents to predict illness class (HC/BD/SZ).ResultsThe offspring-based model separated oHC/oSZ individuals with 77% accuracy (p<0.001), oHC/oBD with 68% accuracy (p<0.001), and oBD/oSZ with 64% accuracy (p<0.01). The adult-based models could separate the patients’ offspring from the healthy offspring with 66–70% accuracy, but oBD from oSZ with lower accuracy (59%). In addition, the offspring models could separate adult patients from control subjects with comparable accuracy (66–68%) and separate the two patient groups with moderate accuracy (69%).DiscussionThe familial high-risk adolescents could be separated from controls with moderate to high accuracy (up to 77%), based on their MRI-scans. Moreover, the brain tissue patterns based on risk (adolescents) or illness (adults) were able to predict (risk) class in the other stage group. These results show (1) that high-risk individuals already show brain abnormalities, and (2) display similarities with abnormalities in ill adults, and (3) which can be used to detect (risk of) the disorder at the individual level. This suggests that MRI-scans, after further improvement and independent validation, may be of added value in the risk profiling of BD and SZ.

A trace map comparison algorithm for the discrete fracture network models of rock masses

Discrete fracture networks (DFN) are widely used to build refined geological models. However, validating whether a refined model can match to reality is a crucial problem, concerning whether the model can be used for analysis. The current validation methods include numerical validation and graphical validation. However, the graphical validation, aiming at estimating the similarity between a simulated trace map and the real trace map by visual observation, is subjective. In this paper, an algorithm for the graphical validation of DFN is set up. Four main indicators, including total gray, gray grade curve, characteristic direction and gray density distribution curve, are presented to assess the similarity between two trace maps. A modified Radon transform and loop cosine similarity are presented based on Radon transform and cosine similarity respectively. Besides, how to use Bézier curve to reduce the edge effect is described. Finally, a case study shows that the new algorithm can effectively distinguish which simulated trace map is more similar to the real trace map.

Modeling Early Postnatal Brain Growth and Development with CT: Changes in the Brain Radiodensity Histogram from Birth to 2 Years.

The majority of brain growth and development occur in the first 2 years of life. This study investigated these changes by analysis of the brain radiodensity histogram of head CT scans from the clinical population, 0-2 years of age. One hundred twenty consecutive head CTs with normal findings meeting the inclusion criteria from children from birth to 2 years were retrospectively identified from 3 different CT scan platforms. Histogram analysis was performed on brain-extracted images, and histogram mean, mode, full width at half maximum, skewness, kurtosis, and SD were correlated with subject age. The effects of scan platform were investigated. Normative curves were fitted by polynomial regression analysis. Average total brain volume was 360 cm3 at birth, 948 cm3 at 1 year, and 1072 cm3 at 2 years. Total brain tissue density showed an 11% increase in mean density at 1 year and 19% at 2 years. Brain radiodensity histogram skewness was positive at birth, declining logarithmically in the first 200 days of life. The histogram kurtosis also decreased in the first 200 days to approach a normal distribution. Direct segmentation of CT images showed that changes in brain radiodensity histogram skewness correlated with, and can be explained by, a relative increase in gray matter volume and an increase in gray and white matter tissue density that occurs during this period of brain maturation. Normative metrics of the brain radiodensity histogram derived from routine clinical head CT images can be used to develop a model of normal brain development.

Grey matter density in the right caudate nucleus predicts aphasic patients’ response to speech comprehension therapy

Grey matter density in the right caudate nucleus predicts aphasic patients’ response to speech comprehension therapy

Apex predators and the facilitation of resource partitioning among mesopredators

Apex predators may influence carnivore communities through the suppression of competitively dominant mesopredators, however they also provide carrion subsidies that could influence foraging and competition among sympatric mesopredators when small prey is scarce. We assessed coyoteCanis latransand red foxVulpes vulpeswinter diet overlap and composition from scats collected in two study areas with 3‐fold difference in grey wolfCanis lupusdensity due to a wolf control program. We hypothesized that differences in diet composition would be driven by the use of carrion, and tested whether 1) apex predators facilitate resource overlap, or 2) apex predators facilitate resource partitioning. We estimated the available biomass of snowshoe hares and voles based on pellet density and vole capture rates in each study area. We used molecular analysis to confirm species identification of predator scats, and used microscopic evaluation of prey remains to analyze diet composition of 471 coyote and fox scats. Ungulate carrion, voles and snowshoe hares comprised 73% of coyote and fox diet, and differences in use of carrion and microtines accounted for nearly 60% of the dissimilarity in diet among these canids. Carrion was the top‐ranked item in the coyote diet in both study areas, whereas carrion use by red foxes declined 3‐fold in the study area with higher wolf and small prey abundance. Diet overlap tended to be lower and diet diversity tended to be higher where wolves were more abundant, though these trends were not statistically significant. Taken together, our findings indicate that carrion provisions could facilitate resource partitioning in mesocarnivore communities by alleviating exploitation competition for small mammals.

Stereological Analysis of the Brain in Methamphetamine Abusers Compared to the Controls

Background: Methamphetamine (MA) is an addictive and stimulant drug that its abuse causes psychological and cognitive symptoms. MA abuse can cause structural changes in the brain. Objectives: The current study aimed to evaluate stereological changes of the brains of MA abusers, compared to the controls. Patients and Methods: The current case-control study was conducted on magnetic resonance (MR) images from MA abusers and healthy controls (n = 10 in each group), in Zahedan, Iran. The convenience sampling method was employed to select the subjects. MR images of the brains of the 2 groups in frontal, coronal, and sagittal axes with 4-mm slide thickness and 0.5-mm intervals were acquired. Parameters including total volume (V) and volume density (Vv) of different parts of the brain were estimated based on the Cavalieri point counting stereological method. To analyze the data, descriptive statistics and the Mann-Whitney U-test were applied. The significance level was considered P < 0.05. Results: The results showed that the volume of the cerebellum, the volume and volume density of the ventricles, and gray matter volume and volume density, and the basal ganglia volume density in MA group was significantly smaller than those of the controls (P < 0.05). But, white matter volume and volume density in the MA abusers were significantly larger than those of the healthy subjects (P < 0.05). In addition, there were no significant differences between the total brain, the hippocampus, and the basal ganglia volumes between the 2 groups. Conclusions: According to the results of the current study, MA abuse can cause structural changes in the brain components. MR imaging by the stereological methods can be employed as a technique to determine the level of such damages in substance abusers.

Population density of eastern grey kangaroos (Macropus giganteus) in a periurban matrix at Coffs Harbour, New South Wales

We surveyed eastern grey kangaroos at four locations at the Northern Beaches region of Coffs Harbour, New South Wales, to estimate densities in this growing peri-urban region. This region is considered a regional hotspot for human–kangaroo conflict, with numerous kangaroo-related incidents in recent years. Direct counts of kangaroos were undertaken every two months during 2016. Kangaroo densities varied between sites, ranging from 0.2 individuals ha–1 to 4.9 individuals ha–1. Because no estimates of population density exist for the Northern Beaches, our results assisted the development of a regional kangaroo management plan, and contribute to a broader understanding of eastern grey kangaroo densities in peri-urban areas.

Radiological Evaluation of Maxillary Sinus Augmentation with Calcium Phosphate Materials and Influence of Titanium Dental Implant Artifacts

Sinus floor augmentation operations with calcium phosphate materials are performed when natural maxillary bone quality and quantity fail to be able to support titanium dental implants. Sinus floor augmentation can be done in one step operation when titanium implant is inserted at the same time when calcium phosphate materials. This type surgery can be done if there is enough maxillary alveolar bone height to stabilize the implant. If there is not enough bone then two step maxillary floor augmentation is performed when dental implant is placed after few months. Calcium phosphate materials are often used for maxillary sinus augmentation. These materials cause remineralization of residual maxillary alveolar bone [1]. That can be observed histologically [2,3]. However histological evaluation often means interference. Radiological investigation can be used to examine postoperatively augmented area. Nowadays cone beam computed tomography (CBCT) is the radiological method of choice for maxillofacial region due to low radiation and high quality images. There was no date found in literature on maxillary bone remineralization measured in voxel grey value density (VV) on CBCT. Rotation movement of CBCT cause beam hardening artifacts [4,5] that can alter correct measurements of bone and augmentation zone radiodensity. The aim of this study was to calculate remineralization of maxillary alveolar bone after augmentation with calcium phosphate materials radiologically and degree of artifacts created by titanium dental implant in CBCT images.

Effects of testosterone treatment on hypothalamic neuroplasticity in female-to-male transgender individuals

Diffusion-weighted imaging (DWI) is used to measure gray matter tissue density and white matter fiber organization/directionality. Recent studies show that DWI also allows for assessing neuroplastic adaptations in the human hypothalamus. To this end, we investigated a potential influence of testosterone replacement therapy on hypothalamic microstructure in female-to-male (FtM) transgender individuals. 25 FtMs were measured at baseline, 4 weeks, and 4 months past treatment start and compared to 25 female and male controls. Our results show androgenization-related reductions in mean diffusivity in the lateral hypothalamus. Significant reductions were observed unilaterally after 1 month and bilaterally after 4 months of testosterone treatment. Moreover, treatment induced increases in free androgen index and bioavailable testosterone were significantly associated with the magnitude of reductions in mean diffusivity. These findings imply microstructural plasticity and potentially related changes in neural activity by testosterone in the adult human hypothalamus and suggest that testosterone replacement therapy in FtMs changes hypothalamic microstructure towards male proportions.

Grey matter concentration revealed by voxel-based morphometry in individuals with cognitive vulnerability to depression

To explore the grey matter concentration in individuals with cognitive vulnerability to depression. Methods: Thirty individuals with cognitive vulnerability to depression and thirty age- and gender-matched healthy controls were enrolled in this study, and they were subjected to magnetic resonance imaging (MRI) examination. The grey matter concentration differences were compared between the two groups by using voxel-based morphometry (VBM) following MRI. Results: Individuals with cognitive vulnerability to depression showed significantly lower grey matter density in bilateral insular, left cerebellum, right supplementary motor area, and left precentral gyrus than those in the healthy controls, while the healthy controls showed significantly lower grey density in the right inferior frontal gyrus, right middle frontal gyrus, and left cuneus than those in the individuals with cognitive vulnerability to depression. Conclusion: Structural brain abnormalities in individuals with cognitive vulnerability to depression might be the neural basis for cognitive vulnerability to depression.

The prognostic value of gray-white matter ratio on brain computed tomography in comatose adult survivors from cardiac arrest

Objective To evaluate the correlation between the gray-white matter ratio (GWR) and the outcomes of comatose adult survivors from cardiac arrest (CA) in Chinese. Methods Sixty-one CA patients checked with CT scans within 72 hours of resuscitation from January 2011 to January 2016 were included in this single-center retrospective study. Gray and white matter density (Hounsfield units) were measured, and the GWRs were calculated according to previous studies. The prognostic values of the GWRs in predicting poor outcomes (Cerebral Performance Category 3-5) were analyzed. Results The density values of gray matter were significantly higher in the good outcome group than those in the poor one. All GWRs were significantly higher in the good outcome group (P < 0.05). A GWR (basal ganglia) < 1.18 predicted poor outcomes with a sensitivity and specificity of 50.0% and 88.2%, respectively (P = 0.012). Conclusions Low GWRs, determined from brain CT scans in comatose CA patients after resuscitation, were associated with poor neurological outcomes. GWR determination from brain CT can be a useful indicator for outcome prediction aiding in an optimal clinical decision process in comatose survivors from CA. Key words: Cardiac arrest; Coma; Computed tomography; Gray-white matter ratio; Prognosis

Accuracy of densitometry of two cone beam computed tomography equipment in comparison with computed tomography.

BackgroundThe use of oral implants has been growing, and cone beam computerized tomography (CBCT) has become the method of choice for oral and maxillofacial radiology.ObjectiveTo assess the accuracy of bone densitometry in two different CBCT devices in comparison with MDCT (multi-detector CT).MethodsDifferent concentrations of urografin, including 2.5%, 5%, 7.5%, 10%, 12.5%, were prepared, and the Hounsfield unit of these solution was measured by two CBCT devices (SORDEX CRANEX 3D and NEWTOM 5G) and one spiral CT device (SOMATOM SENSATION). Difference of output Hounsfield units in each concentration was compared in three devices. Correlation of devices with increase of urografin dose also was evaluated. Statistical analyses of the data were performed using SPSS18 and Kruskal–Wallis and Mann–Whitney U tests, along with Spearman’s correlation coefficient.ResultsThe range of gray density for NEWTOM 5G CBCT, SORDEX 3D CBCT, and SOMATOM CT imaging systems was from 781 to 2311, 427 to 1464, and 222 to 994, respectively. There was significant difference between devices in the Hounsfield unit in all urografin concentrations (p<0.001). Also there was a significant correlation between three devices with increasing the urografin dose (p<0.05; r>0.95)ConclusionOur findings indicated a high correlation and linear relationship between different studied imaging systems. Although utilizing CBCT in the assessment of bone density is useful according to its lower emitted dose and less cost, clinicians should be aware of the issue that the voxel value in CBCT is not as perfect as CT.

Early Brain Edema is a Predictor of In-Hospital Mortality in Traumatic Brain Injury

BackgroundIdentifying patients who may progress to a poor clinical outcome will encourage earlier appropriate therapeutic interventions. Brain edema may contribute to secondary injury in traumatic brain injury (TBI) and thus, may be a useful prognostic indicator. ObjectiveWe determined whether the presence of brain edema on the initial computed tomography (CT) scan of TBI patients would predict poor in-hospital outcome. MethodsWe performed a retrospective review of all trauma patients with nonpenetrating head trauma at a Level I Trauma Center. International Classification of Diseases, Ninth Revision codes indicated the presence of brain edema and we evaluated the validity of this pragmatic assessment quantitatively in a random subset of patients. In-hospital mortality was the primary outcome variable. Univariate analysis and logistic regression identified predictors of mortality in all TBI patients and those with mild TBI. ResultsOver 7200 patients were included in the study, including 6225 with mild TBI. Measurements of gray and white matter CT density verified radiological assessments of brain edema. Patients with documented brain edema had a mortality rate over 10 times that of the entire study population. With logistic regression accounting for Injury Severity Score, Glasgow Coma Scale score, other CT findings, and clinical variables, brain edema predicted an eightfold greater mortality rate in all patients (odds ratio 8.0, 95% confidence interval 4.6–14.0) and fivefold greater mortality rate for mild TBI patients (odds ratio 4.9, 95% confidence interval 2.0–11.7). ConclusionsBrain edema is an independent prognostic variable across all categories of TBI severity. By alerting emergency physicians to patients with poor predicted clinical outcomes, this finding will drive better resource allocation, earlier intervention, and reduced patient mortality.

Different spatial patterns of brain atrophy and global functional connectivity impairments in major depressive disorder

Alterations in grey matter structure and functional connectivity (FC) are pathological features of major depressive disorder (MDD). However, the relationship between brain structural and functional impairments in MDD remains uncertain. Thus, the aim of this study was to investigate the relationship between alterations in grey matter volume (GMV) and resting-state global functional connectivity density (rs-gFCD) in MDD. Forty-five patients with MDD and 48 healthy controls underwent structural and resting-state functional magnetic resonance imaging (fMRI). GMV and rs-gFCD maps of each subject were created, and the intergroup differences in these neuroimaging metrics were evaluated. Compared to healthy controls, patients with MDD displayed reduced GMV in the left insula, putamen, amygdala and hippocampus (mainly in the limbic system). In contrast, decreased rs-gFCD was observed in the left postcentral and precentral gyri, right fusiform gyrus and lingual gyrus (mainly in the sensory system). Furthermore, we found no significant correlations between GMV and rs-gFCD in these brain regions. Finally, overlap ratio analysis demonstrated that the spatial distribution patterns of intergroup differences on the GMV and rs-gFCD maps were distinct. Our findings suggest that the presence of distinct spatial distribution patterns of brain atrophy and global FC impairments might be pathological features of MDD.

Crop diversity loss as primary cause of grey partridge and common pheasant decline in Lower Saxony, Germany.

BackgroundThe grey partridge (Perdix perdix) and the common pheasant (Phasianus colchicus) are galliform birds typical of arable lands in Central Europe and exhibit a partly dramatic negative population trend. In order to understand general habitat preferences we modelled grey partridge and common pheasant densities over the entire range of Lower Saxony. Spatially explicit developments in bird densities were modelled using spatially explicit trends of crop cultivation. Pheasant and grey partridge densities counted annually by over 8000 hunting district holders over 10 years in a range of 3.7 Mio ha constitute a unique dataset (wildlife survey of Lower Saxony). Data on main landscape groups, functional groups of agricultural crops (consisting of 9.5 million fields compiled by the Integrated Administration and Control System) and landscape features were aggregated to 420 municipalities. To model linear 8 or 10 year population trends (for common pheasant and grey partridge respectively) we use rho correlation coefficients of densities, but also rho coefficients of agricultural crops.ResultsAll models confirm a dramatic decline in population densities. The habitat model for the grey partridge shows avoidance of municipalities with a high proportion of woodland and water areas, but a preference for areas with a high proportion of winter grains and high crop diversity. The trend model confirms these findings with a linear positive effect of diversity on grey partridge population development. Similarly, the pheasant avoids wooded areas but showed some preference for municipalities with open water. The effect of maize was found to be positive at medium densities, but negative at very high proportions. Winter grains, landscape features and high crop diversity are favorable. The positive effect of winter grains and higher crop diversity is also supported by the trend model.ConclusionsThe results show the strong importance of diverse crop cultivation. Most incentives favor the cultivation of specific crops, which results in large areas of monocultures. The results confirm the importance of sustainable agricultural policies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12898-016-0093-9) contains supplementary material, which is available to authorized users.

Immunohistochemical evidence of tissue hypoxia and astrogliosis in the rostral ventrolateral medulla of spontaneously hypertensive rats

Increased activity of the sympathetic nervous system has been highlighted as a key factor that contributes to the development and maintenance of arterial hypertension. However, the factors that precipitate sustained increases in sympathetic activity remain poorly understood. Resting tissue oxygen partial pressure (PtO2) in the brainstem of anesthetized spontaneously hypertensive rats (SHRs) has been shown to be lower than in normotensive rats despite normal levels of arterial PO2. A hypoxic environment in the brainstem has been postulated to activate astroglial signalling mechanisms in the rostral ventrolateral medulla (RVLM) which in turn increase the excitability of presympathetic neuronal networks. In this study, we assessed the expression of indirect markers of tissue hypoxia and astroglial cell activation in the RVLM of SHRs and age-matched normotensive Wistar rats. Immunohistochemical labelling for hypoxia-induced factor-1α (HIF-1α) and bound pimonidazole adducts revealed the presence of tissue hypoxia in the RVLM of SHRs. Double immunostaining showed co-localization of bound pimonidazole labelling in putative presympathetic C1 neurons and in astroglial cells. Quantification of glial fibrillary acidic protein (GFAP) immunofluorescence showed relatively higher number of astrocytes and increased GFAP mean grey value density, whilst semi-quantitative analysis of skeletonized GFAP-immunoreactive processes revealed greater % area covered by astrocytic processes in the RVLM of adult SHRs. In conclusion, the morphological findings of tissue hypoxia and astrogliosis within brainstem presympathetic neuronal networks in the SHR support previous observations, showing that low brainstem PtO2 and increased astroglial signalling in the RVLM play an important role in pathological sympathoexcitation associated with the development of arterial hypertension.

Morphometric analysis of endometrial cells in liquid-based cervical cytology samples.

Exfoliated endometrial cells can be seen in cervical smears in association with a wide variety of conditions ranging from normal proliferative endometrium to endometrial malignancies. It is often difficult to differentiate between benign, atypical and malignant endometrial cells using cytomorphology alone. This study was conducted to evaluate if morphometric analysis of endometrial nuclei on liquid-based cervical samples could be of help in differentiating between these endometrial cells. Three groups of cervical samples with histopathological correlation were selected: Group A: showing benign endometrial cells; Group B: showing atypical endometrial cells and Group C: showing malignant endometrial cells. There were 30 cases each in Group A and B and 39 cases in Group C. Image J, NIH, USA was used for selecting the endometrial nuclei and performing the morphometric measurements. MANOVA was used for statistical analysis. The mean nuclear area and nuclear perimeter were significantly different between the three groups of endometrial cells with a P-value <0.05. However, the mean standard deviation of the nuclear area (SDNA) was not significantly different between atypical and malignant endometrial cells (P = 0.765) and the mean nuclear diameter was not statistically different between benign and atypical cells (P = 0.112). Also, the difference in the mean integrated gray density amongst all three groups was not statistically significant (P = 0.397, 0.844, 0.732). We conclude that the morphometric parameters of the nuclear area and nuclear perimeter are helpful in differentiating between benign, atypical and malignant endometrial nuclei even in liquid-based cervical cytology samples.

Neuroanatomical Predictors of Functional Outcome in Individuals at Ultra-High Risk for Psychosis.

Most individuals at ultra-high risk (UHR) for psychosis do not transition to frank illness. Nevertheless, many have poor clinical outcomes and impaired psychosocial functioning. This study used voxel-based morphometry to investigate if baseline grey and white matter brain densities at identification as UHR were associated with functional outcome at medium- to long-term follow-up. Participants were help-seeking UHR individuals (n = 109, 54M:55F) who underwent magnetic resonance imaging at baseline; functional outcome was assessed an average of 9.2 years later. Primary analysis showed that lower baseline grey matter density, but not white matter density, in bilateral frontal and limbic areas, and left cerebellar declive were associated with poorer functional outcome (Social and Occupational Functioning Assessment Scale [SOFAS]). These findings were independent of transition to psychosis or persistence of the at-risk mental state. Similar regions were significantly associated with lower self-reported levels of social functioning and increased negative symptoms at follow-up. Exploratory analyses showed that lower baseline grey matter densities in middle and inferior frontal gyri were significantly associated with decline in Global Assessment of Functioning (GAF) score over follow-up. There was no association between baseline grey matter density and IQ or positive symptoms at follow-up. The current findings provide novel evidence that those with the poorest functional outcomes have the lowest grey matter densities at identification as UHR, regardless of transition status or persistence of the at-risk mental state. Replication and validation of these findings may allow for early identification of poor functional outcome and targeted interventions.

Potential Mechanism For the Elimination of Suicide Attempts by Modified Electroconvulsive Therapy in Drug-naive Patients with Suicidal Depressive Episode: A Pilot Study Report

Background:Modified electroconvulsive therapy (MECT) can rapidly eliminate suicide attempts in patients with suicidal depression. However, no study has investigated the neural mechanisms by which MECT eliminates suicide attempts. Currently, we conducted a study to explore the potential mechanisms by which MECT eliminates suicide attempts in patients with suicidal depressive episodes. Methods:Four drug-naive patients with suicidal depressive episode underwent structural and resting-state functional magnetic resonance imaging scanning before and after MECT treatment. The voxel-based morphometry (VBM) and functional connectivity density mapping(FCDM) methods were used to analyze the imaging data. The gray matter volume (GMV) and resting-state global functional connectivity density (rs-gFCD) were used to evaluate the structural and functional alterations, respectively, that occurred subsequent to MECT. Results:The VBM analysis revealed that MECT induced a GMV increase that was primarily localized to the left dorsolateral prefrontal cortex and bilateral thalamus. The FCDM analysis revealed that MECT induced an rs-gFCD decrease that was mainly localized in the left medial superior frontal gyrus and bilateral orbitofrontal cortex. No overlap existed between brain regions that exhibited structural and functional alterations. Conclusion:The structural and functional alterations subsequent to MECT were mainly located in the brain regions that are related to the suicide attempts in suicidal depressive patients. The brain regions that exhibited structural alterations did not overlap with those that exhibited functional alterations, which suggests that the structural and functional alterations contributed independently to the efficacy of MECT in the elimination of suicide attempts in patients with suicidal depression