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Multisite longitudinal neuroimaging designs are used to identify differential brain structural change associated with onset or progression of disease. The reliability of neuroanatomical measurements over time and across sites is a crucial aspect of power in such studies. Prior work has found that while within-site reliabilities of neuroanatomical measurements are excellent, between-site reliability is generally more modest. Factors that may increase between-site reliability include standardization of scanner platform and sequence parameters and correction for between-scanner variations in gradient nonlinearities. Factors that may improve both between- and within-site reliability include use of registration algorithms that account for individual differences in cortical patterning and shape. In this study 8 healthy volunteers were scanned twice on successive days at 8 sites participating in the North American Prodrome Longitudinal Study (NAPLS). All sites employed 3 Tesla scanners and standardized acquisition parameters. Site accounted for 2 to 30% of the total variance in neuroanatomical measurements. However, site-related variations were trivial (<1%) among sites using the same scanner model and 12-channel coil or when correcting for between-scanner differences in gradient nonlinearity and scaling. Adjusting for individual differences in sulcal-gyral geometries yielded measurements with greater reliabilities than those obtained using an automated approach. Neuroimaging can be performed across multiple sites at the same level of reliability as at a single site, achieving within- and between-site reliabilities of 0.95 or greater for gray matter density in the majority of voxels in the prefrontal and temporal cortical surfaces as well as for the volumes of most subcortical structures. Hum Brain Mapp 35:2424-2434, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Thermenos HW, Makris N, Whitfield-Gabrieli S, Brown AB, Giuliano AJ, Lee EH, Faraone SV, Tsuang MT, Seidman LJ. A functional MRI study of working memory in adolescents and young adults at genetic risk for bipolar disorder: preliminary findings. Bipolar Disord 2011: 13: 272-286. © 2011 The Authors. Journal compilation © 2011 John Wiley & Sons A/S. In this report, we seek to (i) identify a potential neuroimaging endophenotype for bipolar disorder (BD) in emotion regulatory and autonomic circuitry in young first-degree relatives of persons with BD; and (ii) replicate our previous work identifying the functional neuroanatomy of working memory (WM) in an older sample of relatives of persons with BD. Ten adolescent and young adult (age 13-24) unmedicated, non-ill, first-degree relatives of persons with BD (RELS) and 10 demographically comparable healthy controls performed a 2-back WM task and a 0-back control task during functional magnetic resonance imaging (fMRI). fMRI data were collected on a 1.5 Tesla scanner and analyzed using SPM-2. Mood was assessed on the day of scanning. The groups did not differ on any demographic, neuropsychological, or in-scanner task performance variables. In contrast to controls, RELS showed (i) weak task-dependent modulation activity in the cerebellar vermis (CV), insula, and amygdala/parahippocampal region, and (ii) exaggerated modulation of activity in the frontopolar cortex and brainstem, even after controlling for potential confounders. Many of the group differences were driven by differences in activity in the low-level (0-back) baseline task. Young, unmedicated RELS exhibited altered task-dependent modulation of frontopolar, CV, and insula activity during WM, especially during the low-level (0-back) baseline task. Results are largely consistent with our initial study of older adult RELS, suggesting these alterations may represent biomarkers of genetic risk for BD. [ABSTRACT FROM AUTHOR]

The article presents a study that investigated the possible correlation between genetic factors and the volumes of subcortical brain structures. Several models for genetic factors namely a Basal Ganglia/Thalamus factor, a Ventricular factor, a Limbic factor, and a Nucleus Accumbens factor are found to fit the data generated. Genetic patterning among structures that differentiate between brain, different subcortical regions, and cerebrospinal fluid spaces was observed.

First-degree relatives of persons with bipolar disorders (BDs) carry elevated risk for the illness, and manifest deficits in attention and memory (possible "endophenotypes"). However, there is only one published functional magnetic resonance imaging (fMRI) study of candidate endophenotypes in BD. We used fMRI to examine brain function in BD and in first-degree relatives performing a 2-back working memory (WM) task, and correlated brain activity with mood measures taken at the scanning session. Subjects (age 32-46) were 19 persons with BD, 18 unmedicated, non-psychotic first-degree relatives (RELs) of persons with BD, and 19 matched controls, ascertained from a long-term follow-up of a prenatal cohort study in New England. fMRI signal during 2-back and 0-back WM tasks was measured on a Siemens 1.5T MR scanner. fMRI data were analyzed using SPM-2. Persons with BD and RELs failed to suppress activation in the left anterior insula (BA 13) during WM, whereas controls suppressed activation. Compared to controls, RELs also failed to suppress activation in the orbitofrontal cortex (OFC) and superior parietal cortex. Controls and RELs exhibited greater activation than BD individuals in the left frontopolar cortex (BA 10) during WM. Results remained significant after controlling for confounders except for mild attenuation of OFC findings. Significant correlations between brain activity, mood, and WM suggest that activity in WM circuits is affected by activity in emotion-regulatory circuits. Persons with BD and RELs exhibit altered activity in the frontopolar cortex and insula, which may represent biomarkers of genetic risk for BD., ((c) 2009 Wiley-Liss, Inc.)