Background and PurposePostradiation treatment necrosis is one of the most serious late sequelae and appears within 6 months. The magnetic resonance spectroscopy imaging (MRSI) has been used for the detection of brain tumors. The study aimed to determine the radiological accuracy and efficacy in distinguishing recurrent brain tumor from radiation-induced necrosis by identifying pseudoprogression. MethodsThe research was performed in accordance with the preferred reporting items for systematic review and meta-analysis guidelines. International electronic databases including 15 English sources were investigated. A total of 4281 papers with 2159 citations from 15 databases from 2011 to 2021 met the search strategies of magnetic resonance (MR) spectroscopy in recurrent brain tumors and postradiation necrosis. ResultsNine studies were enrolled in the meta-analysis with a total of 354 patients (203 male and 151 female) whose average age ranged from 4 to 74 years. Anbarloui et al., Elias et al., Nemattalla et al., Smith et al., Zeng et al., and Weybright et al. showed strong evidence of heterogeneity regarding choline/N-acetylaspartate (Cho/NAA) ratio in the evaluation of the nine studies. Elias et al., Nemattalla et al., Bobek-Billewicz et al., and Smith et al. showed a high heterogeneity in Cho/creatine (Cr) ratio. Elias et al., Nemattalla et al., Smith et al., and Weybright et al. revealed high heterogeneity in NAA/Cr ratio estimates. ConclusionMR spectroscopy is effective in distinguishing recurrent brain tumors from necrosis. Our meta-analysis revealed that Cho/NAA, Cho/Cr, and NAA/Cr ratios were significantly better predictor of detected recurrent tumor. Therefore, the MRSI is an informative tool in the distinction of tumor recurrence versus necrosis.
Introduction: Plain film abdominal radiographs (PFAs) are frequently the initial investigation ordered for patients with abdominal symptoms. However, increasing use of emergency ultrasound and availability of emergency CT raises the question of whether PFA remains an appropriate first line investigation. We investigated the impact of out of hours (OOH) PFAs on inpatient management. Methods: All consecutive PFAs over an 8-week period were included to determine the impact on patient management. OOH was classified as from 5pm to 9am Monday to Friday, weekends and bank-holidays. PACS and hospital records were accessed to determine patient pathways. The institution is a tertiary referral centre with 850 acute beds and serves a population of 950,000. Results: A total of 758 consecutive PFAs were performed in total (58.3% male, mean age 58.1 (range 0-93)). 310 (40.9%) were requested from the emergency department (ED) and 382 (50.4%) were requested from wards. 160 (21.1%) met the criteria of OOH, of these 120 (72.2%) were from ED and 28 were on adult inpatients. Of these 28, none had a change in management based on the PFA result. Conclusion: Our study suggests that OOH PFAs of inpatients are of limited clinical utility. These patients are exposed to extra radiation. Implications for practice: We propose that OOH PFAs of inpatients should be questioned as a viable investigation due to the limited contribution they offer in managing patients, the deleterious effects they confer on the patient and the associated economic cost. Further studies are needed to assess if these results are generalizable to other large hospitals. (C) 2020 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.
The association of neuroanatomical progression with cognitive and clinical deterioration after first-episode of psychosis remains uncertain. This longitudinal study aims to assess whether i)impaired executive functioning and emotional intelligence at first presentation are associated with progressive prefrontal and orbitofrontal cortical thinning ii)negative symptom severity is linked to progressive prefrontal cortical thinning. 1.5T MRI images were acquired at baseline and after 3.5 years for 20 individuals with first-episode psychosis and 18 controls. The longitudinal pipeline of Freesurfer was employed to parcellate prefrontal cortex at two time points. Baseline cognitive performance was compared between diagnostic groups using MANCOVA. Partial correlations investigated relationships between cognition and negative symptoms at baseline and cortical thickness change over time. Patients displayed poorer performance than controls at baseline in working memory, reasoning/problem solving and emotional intelligence. In patients, loss of prefrontal and orbitofrontal thickness over time was predicted by impaired working memory and emotional intelligence respectively at baseline. Moreover, exploratory analyses revealed that the worsening of negative symptoms over time was significantly related to prefrontal cortical thinning. Results indicate that specific cognitive deficits at the onset of psychotic illness are markers of progressive neuroanatomical deficits and that worsening of negative symptoms occurs with prefrontal thickness reduction as the illness progresses.
Abstract Background The extent and location of longitudinal morphometric changes after first-episode of psychosis (FEP) remains unclear. We investigated the progressive profile of ventricular and cortico-subcortical regions over a 3-year period in FEP patients compared with healthy controls (HC), and whether any progressive neuroanatomical changes were related to clinical factors. Methods High resolution 1.5T T1-weighted MR images were obtained from 28 FEP patients and 28 HCs shortly after presentation to services and again after 3-year follow-up. The longitudinal FreeSurfer pipeline (v.5.3.0) was used for regional volumetric and cortical reconstruction image analyses. Repeated-measures ANCOVA and vertex-wise linear regression analyses were used to compare progressive changes in relation to subcortical structures/ventricles and thickness across the cortical mantle, respectively, between groups. Partial correlations were used to determine associations of progressive neuroanatomical change with clinical and functional characteristics. Results Compared with controls, patients displayed progressively reduced volume of the caudate [F(1,51)=5.86, p=0.02, Hedges’ g=0.66], putamen [F(1,51)=6.06, p=0.02, g=0.67] and thalamus [F(1,51)=6.99, p=0.01, g=0.72], with a trend for increased lateral ventricular volume [F(1,51)=3.37, p=0.07, g=0.50] more prominent on the right [F(1, 51)=4.03, p=0.05], and significantly increased rate of cortical thinning [F(1,52)=5.11, p=0.028)] at a mean difference of 0.844% [95% CI (0.095, 1.593)] in the left lateral orbitofrontal region (LLOFR) over the 3-year period. In FEP individuals, greater reduction in putamen volume over time was associated with low cumulative antipsychotic medication dose (r=0.49, p=0.01), and increasing lateral ventricular volume over time was associated with worsening negative symptoms (r=0.41, p=0.04) and poorer global assessment of functioning (r=-0.41, p=0.04). Discussion Our results demonstrate existence of localised progressive structural disturbance in the subnetwork of the cortico-striato-thalamo-cortical circuitry after the onset of psychosis. Furthermore, increasing ventricular volume is a neuroanatomical marker of poorer clinical and functional outcome. These findings lend weight to the evidence of early progressive brain changes in psychotic disorders and thus, this knowledge could potentially contribute to the identification of imaging biomarkers for timely intervention.
The location, extent and progression of longitudinal morphometric changes after first-episode of psychosis (FEP) remains unclear. We investigated ventricular and cortico-subcortical regions over a 3-year period in FEP patients compared with healthy controls. High resolution 1.5T T1-weighted MR images were obtained at baseline from 28 FEP patients at presentation and 28 controls, and again after 3-years. The longitudinal FreeSurfer pipeline (v.5.3.0) was used for regional volumetric and cortical reconstruction image analyses. Repeated-measures ANCOVA and vertex-wise linear regression analyses compared progressive changes between groups in subcortical structures and cortical thickness respectively. Compared with controls, patients displayed progressively reduced volume of the caudate [F (1,51)=5.86, p=0.02, Hedges' g=0.66], putamen [F (1,51)=6.06, p=0.02, g=0.67], thalamus [F (1,51)=6.99, p=0.01, g=0.72] and increased right lateral ventricular volume [F (1, 51)= 4.03, p=0.05], and significantly increased rate of cortical thinning [F (1,52)=5.11, p=0.028)] at a mean difference of 0.84% [95% CI (0.10, 1.59)] in the left lateral orbitofrontal region over the 3-year period. In patients, greater reduction in putamen volume over time was associated with lower cumulative antipsychotic medication dose (r=0.49, p=0.01), and increasing lateral ventricular volume over time was associated with worsening negative symptoms (r=0.41, p=0.04) and poorer global functioning (r= 0.41, p=0.04). This study demonstrates localised progressive structural abnormalities in the cortico-striato-thalamo-cortical circuit after the onset of psychosis, with increasing ventricular volume noted as a neuroanatomical marker of poorer clinical and functional outcome.
Structural brain volume changes have been demonstrated at the onset of first-episode of psychosis (FEP). However, data pertaining to the potential volumetric progressions remain inconsistent. We examined if there are progressive changes in ventricular and subcortical volumes over a 3-year period in individuals with FEP compared to healthy controls (HC) and if any such changes are associated with clinical and functional outcome.
Background Although repeatedly associated with white matter microstructural alterations, bipolar disorder (BD) has been relatively unexplored using complex network analysis. This method combines structural and diffusion magnetic resonance imaging (MRI) to model the brain as a network and evaluate its topological properties. A group of highly interconnected high-density structures, termed the ‘rich-club’, represents an important network for integration of brain functioning. This study aimed to assess structural and rich-club connectivity properties in BD through graph theory analyses. Method We obtained structural and diffusion MRI scans from 42 euthymic patients with BD type I and 43 age- and gender-matched healthy volunteers. Weighted fractional anisotropy connections mapped between cortical and subcortical structures defined the neuroanatomical networks. Next, we examined between-group differences in features of graph properties and sub-networks. Results Patients exhibited significantly reduced clustering coefficient and global efficiency, compared with controls globally and regionally in frontal and occipital regions. Additionally, patients displayed weaker sub-network connectivity in distributed regions. Rich-club analysis revealed subtly reduced density in patients, which did not withstand multiple comparison correction. However, hub identification in most participants indicated differentially affected rich-club membership in the BD group, with two hubs absent when compared with controls, namely the superior frontal gyrus and thalamus. Conclusions This graph theory analysis presents a thorough investigation of topological features of connectivity in euthymic BD. Abnormalities of global and local measures and network components provide further neuroanatomically specific evidence for distributed dysconnectivity as a trait feature of BD.
Despite evidence that clozapine may be neuroprotective, there are few longitudinal magnetic resonance imaging (MRI) studies that have specifically explored an association between commencement of clozapine treatment for schizophrenia and changes in regional brain volume or cortical thickness. A total of 33 patients with treatment-resistant schizophrenia and 31 healthy controls matched for age and gender underwent structural MRI brain scans at baseline and 6–9 months after commencing clozapine. MRI images were analyzed using SIENA (Structural Image Evaluation, using Normalization, of Atrophy) and FreeSurfer to investigate changes over time in brain volume and cortical thickness respectively. Significantly greater reductions in volume were detected in the right and left medial prefrontal cortex and in the periventricular area in the patient group regardless of treatment response. Widespread further cortical thinning was observed in patients compared with healthy controls. The majority of patients improved symptomatically and functionally over the study period, and patients who improved were more likely to have less cortical thinning of the left medial frontal cortex and the right middle temporal cortex. These findings demonstrate on-going reductions in brain volume and progressive cortical thinning in patients with schizophrenia who are switched to clozapine treatment. It is possible that this gray matter loss reflects a progressive disease process irrespective of medication use or that it is contributed to by switching to clozapine treatment. The clinical improvement of most patients indicates that antipsychotic-related gray matter volume loss may not necessarily be harmful or reflect neurotoxicity.
Previous structural magnetic resonance imaging (S-MRI) studies of bipolar disorder have reported variable morphological changes in subcortical brain structures and ventricles. This study aimed to establish trait-related subcortical volumetric and shape abnormalities in a large, homogeneous sample of prospectively confirmed euthymic bipolar I disorder (BD-I) patients (n=60), compared with healthy volunteers (n=60). Participants were individually matched for age and gender. Volume and shape metrics were derived from manually segmented S-MR images for the hippocampus, amygdala, caudate nucleus, and lateral ventricles. Group differences were analysed, controlling for age, gender and intracranial volume. BD-I patients displayed significantly smaller left hippocampal volumes and significantly larger left lateral ventricle volumes compared with controls. Shape analysis revealed an area of contraction in the anterior head and medial border of the left hippocampus, as well as expansion in the right hippocampal tail medially, in patients compared with controls. There were no significant associations between volume or shape variation and lithium status or duration of use. A reduction in the head of the left hippocampus in BD-I patients is interesting, given this region's link to verbal memory. Shape analysis of lateral ventricular changes in patients indicated that these are not regionally specific.
First episode psychosis (FEP) has been associated with structural brain changes, largely identified by volumetric analyses. Advances in neuroimaging processing have made it possible to measure geometric properties that may identify subtle structural changes not appreciated by a measure of volume alone. In this study we adopt complementary methods of assessing the structural integrity of grey matter in FEP patients and assess whether these relate to patient clinical and functional outcome at 3 year follow-up. 1.5 Tesla T1-weighted Magnetic Resonance (MR) images were acquired for 46 patients experiencing their first episode of psychosis and 46 healthy controls. Cerebral cortical thickness and local gyrification index (LGI) were investigated using FreeSurfer software. Volume and shape of the hippocampus, caudate and lateral ventricles were assessed using manual tracing and spherical harmonics applied for shape description. A cluster of cortical thinning was identified in FEP compared to controls; this was located in the right superior temporal gyrus, sulcus, extended into the middle temporal gyrus (lateral temporal cortex - LTC). Bilateral caudate volumes were significantly lower in FEP relative to controls and the right caudate also displayed regions of shape deflation in the FEP group. No significant structural abnormalities were identified in cortical LGI or hippocampal or lateral ventricle volume/shape. Neither LTC nor caudate abnormalities were related to change in symptom severity or global functioning 3 years later. LTC and caudate abnormalities are present at the first episode of psychosis but do not appear to directly affect clinical or functional outcome.
Diffusion MRI investigations in schizophrenia provide evidence of abnormal white matter (WM) microstructural organization as indicated by reduced fractional anisotropy (FA) primarily in interhemispheric, left frontal and temporal WM. Using tract-based spatial statistics (TBSS), we examined diffusion parameters in a sample of patients with severe chronic schizophrenia. Diffusion MRI data were acquired on 19 patients with chronic severe schizophrenia and 19 age- and gender-matched healthy controls using a 64 gradient direction sequence, (b=1300 s/mm2) collected on a Siemens 1.5T MRI scanner. Diagnosis of schizophrenia was determined by Diagnostic and Statistical Manual for Mental Disorders 4th Edition (DSM-IV) Structured Clinical Interview for DSM disorder (SCID). Patients were treatment resistance, having failed to respond to at least two antipsychotic medications, and had prolonged periods of moderate to severe positive or negative symptoms. Analysis of diffusion parameters was carried out using TBSS. Individuals with chronic severe schizophrenia had significantly reduced FA with corresponding increased radial diffusivity in the genu, body, and splenium of the corpus callosum, the right posterior limb of the internal capsule, right external capsule, and the right temporal inferior longitudinal fasciculus. There were no voxels of significantly increased FA in patients compared with controls. A decrease in splenium FA was shown to be related to a longer illness duration. We detected widespread abnormal diffusivity properties in the callosal and temporal lobe WM regions in individuals with severe chronic schizophrenia who have not previously been exposed to clozapine. These deficits can be driven by a number of factors that are indistinguishable using in vivo diffusion-weighted imaging, but may be related to reduced axonal number or packing density, abnormal glial cell arrangement or function, and reduced myelin.
OBJECTIVES:A broad range of subtle and markedly heterogenous neuroanatomical abnormalities of grey matter and white matter have been reported in bipolar disorder. Euthymic bipolar disorder patients represent a clinically homogenous group in which to identify trait-based biomarkers of bipolar disorder. In this study, we sought to clarify the nature and extent of neuroanatomical differences in a large, clinically homogeneous group of euthymic bipolar disorder patients.METHODS:Structural magnetic resonance imaging (sMRI) was obtained for 60 patients with prospectively confirmed euthymic bipolar I disorder and 60 individually age- and gender-matched healthy volunteers. High angular resolution diffusion tensor imaging (DTI) scans were obtained for a subset of this sample comprising 35 patients and 43 controls. Voxel-based analysis of both sMRI and DTI data sets was performed.RESULTS:Bipolar disorder patients displayed global reductions in white matter volume and fractional anisotropy reductions in the corpus callosum, posterior cingulum, and prefrontal white matter compared with controls. There were corresponding increases in radial diffusivity in the callosal splenium in patients compared with controls. No significant group differences were detected in grey matter. In patients, lithium was associated with a bilateral increase in grey matter volume in the temporal lobes, but not with any DTI parameter.CONCLUSIONS:Euthymic bipolar I disorder is characterized by both diffuse global white matter deficits and potential regional disorganization in interhemispheric and longitudinal tracts, while grey matter appears to be preserved.
The neurobiological correlates of impaired insight in psychotic illness remain uncertain and may be confounded by factors such as illness progression and medication use. Our study consisted of two separate experiments. In the first experiment, we examined the association between measures of insight and regional brain volume in thirty-two patients with first-episode psychosis. In the second experiment, we looked at similar associations in thirty individuals with chronic schizophrenia. Detailed measures of symptom awareness and symptom attribution were obtained using the Scale to assess Unawareness of Mental Disorder. MRI scans were acquired and analysed using Statistical Non-Parametric Mapping for voxel-based analyses of grey matter maps. Regression models were used to assess the relationship between insight and grey matter volume in both the first-episode psychosis and the chronic schizophrenia experiments whilst controlling for potential confounds. In first-episode psychosis patients, symptom misattribution was associated with increased grey matter in the right and left caudate, right thalamus, left insula, putamen and cerebellum. In the chronic schizophrenia study, there were no significant associations between regional grey matter volume and measures of insight. These findings suggest that neuroplastic changes within subcortical and frontotemporal regions are associated with impaired insight in individuals during their first episode of psychosis.
Wild boar (Sus scrofa) is the most common native wildlife species causing crop damage in some regions of China. However, in Tropical East Asia, there is limited knowledge on wild boar ecology for application in management and policy decisions. To address this void, we examined wild boar sex-age class structure, group size and space use variation in the Naban River Watershed National Nature Reserve in Xishuangbanna Dai Autonomous Prefecture, Yunnan province, Southwestern China, using 4 years of camera trap data. We found that the adult sex ratio was slightly skewed towards females, and that adults and subadults were the dominate age classes. The annual relative abundance for each age class exhibited a bimodal distribution pattern: the abundance of subadults and adults peaked in May and October, while the abundance of piglets peaked in June and October. Mean group sizes (1.6 ± 1.1) were smaller than the typical mean group of 4 individuals observed in Europe. The space use patterns differed by age class, with piglets preferring forest interior regions while adult males were active near the villages. As such, controlling the adult male population is the most direct way to address crop raiding concerns. On the other hand, protecting piglets would have beneficial effects as potential prey for rare carnivore species of conservation concern that are limited to reserve inner zones.
High doses of antipsychotics have been associated with loss in cortical and total gray matter in schizophrenia. However, previous imaging studies have not taken benzodiazepine use into account, in spite of evidence suggesting adverse effects such as cognitive impairment and increased mortality. In this Northern Finland Birth Cohort 1966 study, 69 controls and 38 individuals with schizophrenia underwent brain MRI at the ages of 34 and 43 years. At baseline, the average illness duration was over 10 years. Brain structures were delineated using an automated volumetry system, volBrain, and medication data on cumulative antipsychotic and benzodiazepine doses were collected using medical records and interviews. We used linear regression with intracranial volume and sex as covariates; illness severity was also taken into account. Though both medication doses associated to volumetric changes in subcortical structures, after adjusting for each other and the average PANSS total score, higher scan-interval antipsychotic dose associated only to volume increase in lateral ventricles and higher benzodiazepine dose associated with volume decrease in the caudate nucleus. To our knowledge, there are no previous studies reporting associations between benzodiazepine dose and brain structural changes. Further studies should focus on how these observations correspond to cognition and functioning.