Structural MR image processing using the BRAINS2 toolbox.
ABSTRACT Medical imaging has opened a new door into biomedical research. In order to study various diseases of the brain and detect their impact on brain structure, robust and user friendly image processing packages are required. These packages must be multi-faceted to distinguish variations in size, shape, volume, and the ability to detect longitudinal changes over the course of an illness. This paper describes the BRAINS2 image processing package, which contains both manual and automated tools for structural identification, methods for tissue classification and cortical surface generation. These features are described in detail, as well as the reliability of these procedures.
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ABSTRACT: Background: Psychotic depression is arguably the most diagnostically stable subtype of major depressive disorder, and an attractive target of study in a famously heterogeneous mental illness. Previous imaging studies have identified abnormal volumes of the hippocampus, amygdala, and subcallosal region of the anterior cingulate cortex (scACC ) in psychotic depression, though studies have not yet examined the role of family history of depression in these relationships. Methods: 20 participants with psychotic depression preparing to undergo electroconvulsive therapy and 20 healthy comparison participants (13 women and 7 men in each group) underwent structural brain imaging in a 1.5T MRI scanner. 15 of the psychotic depression group had a first-degree relative with diagnosed affective disorders, while the healthy control group had no first-degree relatives with affective disorders. Depression severity was assessed with the Hamilton Depression Rating Scale and duration of illness was assessed in all patients. Automated neural nets were used to isolate the hippocampi and amygdalae in each scan, and an established manual method was used to parcellate the anterior cingulate cortex into dorsal, rostral, subcallosal, and subgenual regions. The volumes of these regions were compared between groups. Effects of laterality and family history of affective disorders were examined as well. Results: Patients with psychotic depression had significantly smaller left scACC and bilateral hippocampal volumes, while no group differences in other anterior cingulate cortex subregions or amygdala volumes were present. Hippocampal atrophy was found in all patients with psychotic depression, but reduced left scACC volume was found only in the patients with a family history of depression. Conclusions: Patients with psychotic depression showed significant reduction in hippocampal volume bilaterally, perhaps due to high cortisol states associated with this illness. Reduced left scACC volume may be a vulnerability factor related to family history of depression.PLoS ONE 10/2014; DOI:10.1371/journal.pone.0110770 · 3.53 Impact Factor
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ABSTRACT: The post-central gyrus (PoCG) has received little attention in brain imaging literature. However, some magnetic resonance imaging (MRI) studies have detected the presence of PoCG abnormalities in patients with schizophrenia. Fifty-six first-episode schizophrenia patients, selected through the PAFIP Program and carefully assessed for dimensional psychopathology and cognitive functioning, and 56 matched healthy controls were scanned twice over 1-year follow-up. PoCG gray matter volumes were measured at both time-points and compared between the groups. Differences in volume change over time and the relationship between PoCG volume and clinical and cognitive variables were also investigated. The right PoCG volume was significantly smaller in patients than in controls at the 1-year follow-up; furthermore, it was significantly smaller in male patients compared with male controls, with no differences in female. Although there was no significant time by group interaction in the overall sample, a trend-level interaction was found for the right PoCG in males. This is the first study, as per our knowledge, to focus on PoCG in first-episode schizophrenia patients. The presence of PoCG abnormalities in the first year of schizophrenia suggests a possible contribution to the pathophysiology of the illness, probably as part of a more extensive network of abnormalities.Psychiatry Research Neuroimaging 11/2014; DOI:10.1016/j.pscychresns.2014.10.023 · 2.83 Impact Factor