Whole-brain Magnetic Resonance Imaging Research Articles

Lower anterior cingulate volume in seriously violent men with antisocial personality disorder or schizophrenia and a history of childhood abuse

Antisocial personality disorder (ASPD) and schizophrenia, as well as childhood abuse, are associated with violent behaviour and show marked volumetric reduction in the anterior cingulate (AC), a brain region implicated in regulation of violence through its involvement in decision making, empathy, impulse control, and emotion regulation. The present study examined, for the first time to the authors' knowledge, the grey matter volume of the AC in relation to seriously violent behaviour and childhood psychosocial deprivation (including physical and sexual abuse) in the context of a mental disorder (schizophrenia or ASPD). Fifty-seven men [14 with ASPD and a history of serious violence; 13 with schizophrenia and a history of serious violence (VSZ); 15 with schizophrenia without a violence history (SZ); 15 nonviolent healthy participants] underwent whole-brain magnetic resonance imaging and were rated on the presence of physical abuse, sexual abuse, neglect, extreme poverty, foster home placement, criminal parent, severe family conflict, and broken home (collectively 'psychosocial deprivation'). Stereological volumetric ratings of the AC were examined for group differences and their association with childhood psychosocial deprivation. A higher proportion of ASPD and VSZ patients had suffered psychosocial deprivation as children, in particular severe physical abuse, relative to SZ patients and healthy participants. ASPD and VSZ, but not SZ, patients had significantly lower AC volume relative to healthy participants. AC volumes correlated negatively with (total) psychosocial deprivation as well as physical and sexual abuse ratings. Group differences in AC volume became nonsignificant when psychosocial deprivation ratings were covaried for. Violent mentally disordered individuals with ASPD or schizophrenia suffer from a significant AC volume loss and this deficit, at least in part, is explained by their histories of stressful childhood experiences. Current and future therapies aiming to reduce violence in such populations would benefit by attending to biological (and other) correlates of childhood abuse.

Different susceptibility of medial temporal lobe and basal ganglia atrophy rates to vascular risk factors

Atrophy of the medial temporal lobe (MTL) and basal ganglia (BG) are characteristic of various neurodegenerative diseases in older people. In search of potentially modifiable factors that lead to atrophy in these structures, we studied the association of vascular risk factors with atrophy of the MTL and BG in 368 nondemented men and women (born, 1907–1935) who participated in the Age, Gene/Environment, Susceptibility-Reykjavik Study. A fully automated segmentation pipeline estimated volumes of the MTL and BG from whole-brain magnetic resonance imaging performed at baseline and 2.4 years later. Linear regression models showed higher systolic and diastolic blood pressures and the presence of Apo E ε4 were independently associated with increased atrophy of the MTL but no association of vascular risk factors with atrophy of the BG. The different susceptibility of MTL and BG atrophy to the vascular risk factors suggests perfusion of the BG is relatively preserved when vascular risk factors are present.

Magnetic resonance volumetry reveals focal brain atrophy in transient epileptic amnesia

Transient epileptic amnesia (TEA) is a recently described epilepsy syndrome characterized by recurrent episodes of isolated memory loss. It is associated with two unusual forms of interictal memory impairment: accelerated long-term forgetting (ALF) and autobiographical amnesia. We investigated the neural basis of TEA using manual volumetry and automated multi-atlas-based segmentation of whole-brain magnetic resonance imaging data from 40 patients with TEA and 20 healthy controls. Both methods confirmed the presence of subtle, bilateral hippocampal atrophy. Additional atrophy was revealed in perirhinal and orbitofrontal cortices. The volumes of these regions correlated with anterograde memory performance. No structural correlates were found for ALF or autobiographical amnesia. The results support the hypothesis that TEA is a focal medial temporal lobe epilepsy syndrome but reveal additional pathology in connected brain regions. The unusual interictal memory deficits of TEA remain unexplained by structural pathology and may reflect physiological disruption of memory networks by subclinical epileptiform activity.

Consistent Neurodegeneration and Its Association with Clinical Progression in Huntington's Disease: A Coordinate-Based Meta-Analysis

Background: The neuropathological hallmark of Huntington's disease (HD) is progressive striatal loss starting several years prior to clinical onset. In the past decade, whole-brain magnetic resonance imaging (MRI) studies have provided accumulating evidence for widely distributed cortical and subcortical atrophy in the early course of the disease. Objective: In order to synthesize current morphometric MRI findings and to investigate the impact of clinical and genetic features on structural changes, we performed a coordinate-based meta-analysis of voxel-based morphometry (VBM) studies in HD. Methods: Twenty HD samples derived from 17 studies were integrated in the analysis comparing a total of 685 HD mutation carriers [345 presymptomatic (pre-HD) and 340 symptomatic (symp-HD) subjects] and 507 controls. Convergent findings across studies were delineated using the anatomical likelihood estimation approach. Effects of genetic and clinical parameters on the likelihood of observing VBM findings were calculated by means of correlation analyses. Results: Pre-HD studies featured convergent evidence for neurodegeneration in the basal ganglia, amygdala, thalamus, insula and occipital regions. In symp-HD, cerebral atrophy was more pronounced and spread to cortical regions (i.e. inferior frontal, premotor, sensorimotor, midcingulate, frontoparietal and temporoparietal cortices). Higher cytosine-adenosine-guanosine repeats were associated with striatal degeneration, while parameters of disease progression and motor impairment additionally correlated with cortical atrophy, especially in sensorimotor areas. Conclusion: This first quantitative meta-analysis in HD demonstrates the extent of striatal atrophy and further consistent extrastriatal degeneration before clinical conversion. Sensorimotor areas seem to be core regions affected in symp-HD and, along with widespread cortical atrophy, may account for the clinical heterogeneity in HD.

Effects of MRI scan acceleration on brain volume measurement consistency

To evaluate the effects of recent advances in magnetic resonance imaging (MRI) radiofrequency (RF) coil and parallel imaging technology on brain volume measurement consistency. In all, 103 whole-brain MRI volumes were acquired at a clinical 3T MRI, equipped with a 12- and 32-channel head coil, using the T1-weighted protocol as employed in the Alzheimer's Disease Neuroimaging Initiative study with parallel imaging accelerations ranging from 1 to 5. An experienced reader performed qualitative ratings of the images. For quantitative analysis, differences in composite width (CW, a measure of image similarity) and boundary shift integral (BSI, a measure of whole-brain atrophy) were calculated. Intra- and intersession comparisons of CW and BSI measures from scans with equal acceleration demonstrated excellent scan-rescan accuracy, even at the highest acceleration applied. Pairs-of-scans acquired with different accelerations exhibited poor scan-rescan consistency only when differences in the acceleration factor were maximized. A change in the coil hardware between compared scans was found to bias the BSI measure. The most important findings are that the accelerated acquisitions appear to be compatible with the assessment of high-quality quantitative information and that for highest scan-rescan accuracy in serial scans the acquisition protocol should be kept as consistent as possible over time.

Late-Life Bipolar Disorder

As our society ages, it is critical that we expand our understanding of how best to provide care and services for the growing population of elderly patients with bipolar disorder (BD). For many years, there was a dearth of publications focused on the topic of late-life BD. Indeed, the current literature base on geriatric BD is still insufficient to address critical questions regarding etiology, assessment, treatment, and prognosis. In this special issue, we focus on BD in later life and present a series of articles that we believe will be of interest to clinicians and researchers. In the first article, Al Jurdi and colleagues used data from the National Institute of Mental Health-funded Systematic Treatment Enhancement Program for BD (STEP-BD) and compared the presence and severity of acute mood elevation (mania and hypomania) and acute depression symptoms between younger (20-59 years old) and older individuals ( 60 years old). With the exception of distractibility, all acute depression symptoms presented with comparable frequency and severity between younger and older individuals. Huang and colleagues examined the rate of silent cerebral infarctions and risk factors for cerebral infarction in 43 elderly patients with BD using whole-brain magnetic resonance imaging. Their analyses focus on the relationships between cerebral vascular disease, metabolic illness, and bipolarity. Their analyses support the understanding that there are shared neuroprogressive pathways that underlie vascular medical comorbidity, cognitive dysfunction, and mood dysregulation in BD. Lala and Sajatovic summarize the literature on comorbidity in bipolar adults aged >50 years. Psychiatric comorbidity rates appear lower than in younger BD populations, with the most common concurrent illnesses being anxiety and substance use disorders. While older adults with BD have on average of 3 to 4 medical comorbid conditions, medical condition rates appear similar among geriatric patients with and without BD. Avari and Young present a case report of BD in a patient with antiphospholipid syndrome (APS). They present this case in the context of one previous case report and literature linking APS-related immune markers to various neuropsychiatric disorders. They discuss potential vascular and direct mechanisms pertinent to an association of APS with BD, if demonstrated. They encourage additional case descriptions and suggest possible systematic studies. Bhalerao and colleagues report on mortality risk with use of atypical antipsychotics in geriatric BD. US national data from the Department of Veterans Affairs included registry information on 4717 patients 65 years and identified 6-month mortality rates with a new start of an atypical antipsychotic or valproic acid and derivatives during fiscal years 2001 to 2008. The authors report differences in mortality risks among individual antipsychotic agents, a finding that clearly demonstrates the need for continued investigation on currently used psychotropic agents in bipolar elders. Gildengers and colleagues present a secondary analysis from clinical trial data on correlates of treatment response in depressed older adults with BD. They are interested in whether an agent such as lamotrigine that appears to reduce oxidative stress is particularly effective in patients with high vascular medical comorbidity in the context of depressive illness. They present an approach to target treatment to those individuals who may respond most robustly to this type of intervention. Using a novel imaging technique, phosphorus magnetic resonance spectroscopy, Forester and colleagues examine bioenergetic pathways related to bipolar depression in older adults. They look at whether the forward rate constant of creatine kinase (kfor) is altered in older adults with bipolar depression and whether CoEnzyme Q 10, known to have properties that enhance mitochondrial function, increases kfor in older bipolar individuals compared with untreated ageand sex-matched controls. Their study builds on the growing interest in dysfunctional mitochondrial energy metabolism in BD. Rej and Shulman present a systematic review of all studies pertaining to the effects of lithium on the kidney in older adults. They note that age-specific studies are few and conclude that there is no compelling evidence for general avoidance of use of lithium in elderly individuals based on concerns about renal effects. They suggest guidelines for the approach to lithium management in elderly individuals. Finally, Al Jurdi and colleagues conducted a secondary analysis based upon the baseline data from 100 bipolar elderly individuals participating in a pharmacologic treatment Journal of Geriatric Psychiatry and Neurology 25(1) 4-5 a The Author(s) 2012 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0891988712439691 http://jgpn.sagepub.com

The Risk Factors for Elderly Patients With Bipolar Disorder Having Cerebral Infarction

Patients with bipolar disorder are at high risk of developing strokes in the older life. Silent cerebral infarctions (SCIs) could be common in the elderly patients with bipolar disorder, but only small sample size reports are available. The purpose of this study was to assess the proportion of SCIs and determine the risk factors for cerebral infarction in elderly patients with bipolar disorder. We recruited 43 patients with bipolar disorder over the age of 60 to undergo whole-brain magnetic resonance imaging (MRI). We divided them into 2 groups depending on whether infarction was present, and compared the potential variables of these 2 groups. There were 28 elderly patients with bipolar disorder (65.1%) having MRI-proven cerebral infarction. The SCIs were detected in 59.5% (N = 22) of 37 patients without a history of stroke, including 61.3% of 13 patients with late-onset age (>50 years) and 46.7% of 30 patients with typical-onset age (<50 years). Logistic regression revealed that comorbidity with metabolic diseases (95% confidence interval [CI] for odds ratio [OR] = 1.24-40.59) was most strongly associated with cerebral infarction. The leukocyte counts (95% CI for OR = 1.10-3.93) and fasting blood sugar (95% CI for OR = 1.00-1.07) during the most recent acute psychiatric admission may be substituted as the risk factors. Cerebral infarctions tend to be neglected in more than half of the elderly patients with bipolar disorder, regardless of their age at onset. Metabolic abnormality and systemic inflammation may be the risk factors.

Learning new color names produces rapid increase in gray matter in the intact adult human cortex

The human brain has been shown to exhibit changes in the volume and density of gray matter as a result of training over periods of several weeks or longer. We show that these changes can be induced much faster by using a training method that is claimed to simulate the rapid learning of word meanings by children. Using whole-brain magnetic resonance imaging (MRI) we show that learning newly defined and named subcategories of the universal categories green and blue in a period of 2 h increases the volume of gray matter in V2/3 of the left visual cortex, a region known to mediate color vision. This pattern of findings demonstrates that the anatomical structure of the adult human brain can change very quickly, specifically during the acquisition of new, named categories. Also, prior behavioral and neuroimaging research has shown that differences between languages in the boundaries of named color categories influence the categorical perception of color, as assessed by judgments of relative similarity, by response time in alternative forced-choice tasks, and by visual search. Moreover, further behavioral studies (visual search) and brain imaging studies have suggested strongly that the categorical effect of language on color processing is left-lateralized, i.e., mediated by activity in the left cerebral hemisphere in adults (hence "lateralized Whorfian" effects). The present results appear to provide a structural basis in the brain for the behavioral and neurophysiologically observed indices of these Whorfian effects on color processing.

Effect of Chronic Antipsychotic Treatment on Brain Structure: A Serial Magnetic Resonance Imaging Study with Ex Vivo and Postmortem Confirmation

There is increasing evidence that antipsychotic (APD) may affect brain structure directly. To examine this, we developed a rodent model that uses clinically relevant doses and serial magnetic resonance imaging (MRI), followed by postmortem histopathological analysis to study the effects of APD on brain structures. Antipsychotic , haloperidol, and olanzapine were continuously administered to rats via osmotic minipumps to maintain clinic-like steady state levels for 8 weeks. Longitudinal in vivo MRI scanning (T₂-weighted) was carried out at baseline, 4 weeks, and 8 weeks, after which animals were perfused and their brains preserved for ex vivo MRI scanning. Region of interest analyses were performed on magnetic resonance images (both in vivo as well as ex vivo) along with postmortem stereology using the Cavalieri estimator probe. Chronic (8 weeks) exposure to both haloperidol and olanzapine resulted in significant decreases in whole-brain volume (6% to 8%) compared with vehicle-treated control subjects, driven mainly by a decrease in frontal cerebral cortex volume (8% to 12%). Hippocampal, corpus striatum, lateral ventricles, and corpus callosum volumes were not significantly different from control subjects, suggesting a differential effect of APD on the cortex. These results were corroborated by ex vivo MRI scans and decreased cortical volume was confirmed postmortem by stereology. This is the first systematic whole-brain MRI study of the effects of APD, which highlights significant effects on the cortex. Although caution needs to be exerted when extrapolating results from animals to patients, the approach provides a tractable method for linking in vivo MRI findings to their histopathological origins.

Cross-Sectional and Longitudinal Assessment of Structural Brain Alterations in Melancholic Depression

Whole-brain imaging approaches may contribute to the characterization of neuroanatomic alterations in major depression, especially in clinically homogenous patient groups such as those with melancholic features. We assessed brain anatomic alterations, both cross-sectionally and longitudinally, in patients with melancholic depression using a whole-brain voxel-wise approach. Whole-brain magnetic resonance images were collected from a relatively aged sample of 70 consecutively recruited major depressive disorder inpatients with melancholic features and from a group of 40 healthy control subjects. All patients were clinically followed for at least 2 years, and a subset of 30 depressive patients and 20 control subjects were rescanned after a 7-year period. Imaging data were analyzed with voxel- and tensor-based morphometry techniques. Melancholic patients showed gray matter reductions in the left insula and white matter increases in the upper brainstem tegmentum. Male patients showed gray matter decreases in the right thalamus, and periventricular white matter reductions were specifically observed in older patients. Volume decreases in the left insula, hippocampus, and lateral parietal cortex predicted a slower recovery after treatment initiation. In longitudinal assessment, white matter of the upper brainstem tegmentum showed a different temporal evolution between groups. Additionally, bilateral gray matter reductions in the insulae were associated with the number of relapses during follow-up. Structural alterations were identified in regions potentially related to relevant aspects of melancholia pathophysiology. Longitudinal analyses indicated region-specific interactions of baseline alterations with age as well as a significant association of clinical severity with focal changes occurring over time.

Localization of white-matter lesions and effect of vascular risk factors in late-onset major depression

Several studies suggest that patients with late-onset major depression (MD) have an increased load of cerebral white-matter lesions (WMLs) compared with age-matched controls. Vascular risk factors such as hypertension and smoking may confound such findings. Our aim was to investigate the association between the localization and load of WMLs in late-onset MD with respect to vascular risk factors. We examined 22 consecutive patients with late-onset first-episode MD and 22 age- and gender-matched controls using whole-brain magnetic resonance imaging (MRI). The localization, number and volume of WMLs were compared between patients and controls, while testing the effect of vascular risk factors. Among subjects with one or more WMLs, patients displayed a significantly higher WML density in two white-matter tracts: the left superior longitudinal fasciculus and the right frontal projections of the corpus callosum. These tracts are part of circuitries essential for cognitive and emotional functions. Analyses revealed no significant difference in the total number and volume of WMLs between groups. Patients and controls showed no difference in vascular risk factors, except for smoking. Lesion load was highly correlated with smoking. Our results indicate that lesion localization rather than lesion load differs between patients with late-onset MD and controls. Increased lesion density in regions associated with cognitive and emotional functions may be crucial in late-onset MD, and vascular risk factors such as smoking may play an important role in the pathophysiology of late-onset MD, consistent with the vascular depression hypothesis.

Rapid Whole-Brain Magnetic Resonance Imaging With Isotropic Resolution at 3 Tesla

Isotropic imaging offers the potential of improving lesion detection and imaging efficiency by enabling orthogonal image reformations without loss of spatial resolution. However, lengthy scan times for T1-weighted isotropic data acquisitions have been an impediment to the routine clinical application of this approach. We tested the feasibility of using the improved signal-to-noise ratio at 3 Tesla to perform rapid, whole-brain T1-weighted imaging with isotropic 0.8 mm x 0.8 mm x 0.8 mm (0.51 mm3) voxels. The method was validated in healthy volunteers and patients.Eight healthy subjects were imaged pre- and postcontrast on a 3 Tesla MR system. T1-weighted, 3-dimensional spoiled gradient-echo (3D SPGR) data were acquired at 0.8-mm slice thickness and reconstructed at 2-mm thickness in 3 orthogonal orientations. Scan time was 4 minutes 42 seconds. The technique was compared with inversion recovery-prepared spoiled gradient-echo (SPGR-IR) and 2D spin-echo (SE) for comparable spatial resolution and scan time. It was then tested in comparison with 2D SE in a series of 10 patients with enhancing brain lesions.The 3D SPGR technique provided approximately twice the contrast-to-noise ratio (CNR) of SPGR-IR and 50% greater CNR than 2D SE for discriminating gray and white matter. Image quality ratings, evaluated with nonparametric analyses, were also significantly higher for 3D SPGR in both volunteers (P < 0.05) and patients with enhancing lesions (P < 0.05). Of particular note was the elimination of postcontrast vessel pulsation artifacts, which were commonly present with 2D SE, and more uniform hypointensity of cerebrospinal fluid. Lesion enhancement in patients did not differ significantly for 2D SE and 3D SPGR.Our results demonstrate the feasibility of rapid, whole-brain isotropic imaging at 3 Tesla using submillimeter voxels. Artifacts were minimal, especially compared with 2D SE, whereas CNR was 2-fold better than SPGR-IR. The capability for creating reformatted images in orthogonal orientations from a single isotropic acquisition greatly improves efficiency compared with 2D acquisitions acquired in multiple planes. Although further clinical study is needed in a larger patient cohort, these initial results suggest substantial clinical promise for the technique.

Regional white matter decreases in alzheimer's disease using optimized voxel-based morphometry

Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD.

Gray matter abnormalities in developmental stuttering determined with voxel-based morphometry

To investigate the differences of regional grey matter volume between adults with persistent developmental stuttering and fluent speaking adults, and to determine whether stutterers have anomalous anatomy of speech-relevant brain areas that possibly affect speech fluency. High-resolution magnetic resonance imaging (MRI) scanning was performed on 10 adults with developmental stuttering, aged 26 (21 - 35) with the onset age of 4 (3 - 7) and 12 age, sex, hand preference, and education-matched controls. The customized brain templates were created in order to improve spatial normalization and segmentation. Then automated preprocessing of MRI data was conducted using an optimized version of VBM, a fully automated unbiased and objective whole-brain MRI analysis technique. VBM analysis revealed that compared with the controls, the stuttering adults had significant clusters of locally gray matter volume increased in the superior temporal, middle temporal, precentral and postcentral gyrus, and inferior parietal lobule of the bilateral hemisphere (P < 0.001), the numbers of increased gray matter volume in the right and left hemispheres were 60,247 and 48,782 voxels respectively. The, Grey matter decrease was shown with an overall decreased gray matter volume of 32 394 voxels, mainly in the bilateral cerebella posterior lobe and dorsal part of medulla, especially inferior semi-lunar lobule, followed by cerebellar tonsil and bilateral medulla in comparison with the controls (P < 0.001). The reduction of the regional gray matter volume of bilateral cerebella and medulla is related to the neural mechanism of the controlling disorder of speech production and may be the essential cause of stuttering. Some areas with increased gray matter volume in temporal lobe, parietal lobe, and frontal lobe, may be the result of long term functional compensation for the cerebella and medulla function deficiency.

Brain Structure in Prenatal Stroke: Quantitative Magnetic Resonance Imaging (MRI) Analysis

Neonatal stroke outcome studies demonstrate variable findings of either relatively spared intellectual function or persistent impairments. Volumetric measurement of the brain can provide more precise data on lesion-cognition outcomes. We studied 7 children with unilateral focal lesions from prenatal stroke. Whole-brain magnetic resonance imaging scans were analyzed to produce volumes of cortical gray matter, total white matter, cerebrospinal fluid, lesion, and lesion constricted fluid, and we ascertained the relationship of morphometric variables to intellectual and clinical outcome. Children with cystic encephalomalacia plus atrophy had poorer outcomes than children with atrophy or gliosis alone. These children also demonstrated the largest lesion size, smallest gray matter volume, and greatest proportion of hyperintense white matter in the affected hemisphere. Findings suggest that the type and size of the lesion, in addition to the integrity of white matter and residual cortex, may be better predictors of intellectual functioning than either of these indices alone.

A neonatal atlas template for spatial normalization of whole-brain magnetic resonance images of newborns: Preliminary results

Commonly used brain templates are based on adults' or children's brains. In this study, we create a neonatal brain template. This becomes necessary because of the pronounced differences not only in size but even more importantly in geometrical proportions of the brains of adults and children as compared to the ones of newborns. The template is created based on high resolution T1 magnetic resonance images of 7 individuals with gestational ages between 39 and 42 weeks at the dates of examination. As usual, the created template presents two characteristics in a single image: an average intensity and an average shape. The normalization process to map subjects to the same space is done using SPM2 (Statistical Parametric Mapping) and its deformation toolbox. It consists of two steps: an affine and a nonlinear registration for global and local alignments, respectively. The template was evaluated by (i) study of anatomical local deviations and (ii) amount of local deformations of brain tissues in normalized neonatal images. The extracted results were compared with the ones obtained by normalization using adult and pediatric templates. It was shown that the application of our neonatal brain template for alignment of neonatal images results in a pronounced increase in performance of the normalization procedure as indicated by reduction of deviation of anatomical equivalent structures. The neonatal atlas template is freely downloadable from http://www.u-picardie.fr/labo/GRAMFC.

Identifying patients with obsessive–compulsive disorder using whole-brain anatomy

Structural neuroimaging studies have reported a variety of brain alterations between groups of obsessive–compulsive disorder (OCD) patients and healthy controls. However, the large heterogeneity in discrete anatomical measures that exists among patients prevents a clear discrimination of single patients from healthy subjects. This reduces the potential clinical applicability of structural neuroimaging studies. In the present study we assessed the feasibility of identifying OCD patients on the basis of whole-brain anatomical alterations. Whole-brain magnetic resonance images were collected from two consecutive samples of OCD outpatients (n=72 and n=30), and control subjects (n=72 and n=30). We computed the whole-brain (voxel-wise) pattern of structural difference between OCD patients and control subjects at the group level. A single expression value of this difference pattern was calculated for each subject, expressing their degree of ‘OCD-like’ anatomical alteration. Accuracy of patient classification based on these expression values was assessed using two validation approaches. Firstly, using a cross-validation method, we obtained a high classification accuracy (average of the sensitivity and specificity indices) of 93.1%. In a second assessment, which classified new groups of OCD patients and control subjects, overall accuracy was lower at 76.6%. Individual expression values for OCD patients were significantly correlated with overall symptom severity as measured by the Y-BOCS scale. Our results suggest that OCD patients can be identified on the basis of whole-brain structural alterations, although the accuracy of our approach may be limited by the inherent variability of psychiatric populations. Nevertheless, the anatomical characterization of individual patients may ultimately provide the psychiatrist with relevant biological information.

No evidence for preferential involvement of medial temporal lobe structures in high-functioning autism

Autism is a neurodevelopmental disorder associated with slight increases in brain volume. There has been some suggestion that medial temporal lobe structures may be preferentially involved in this disorder, although results have not always been consistent. Here, we investigate amygdala and hippocampus volumes in medication-naive subjects with high-functioning autism. Whole-brain magnetic resonance imaging scans were acquired from 42 patients and 42 closely matched, healthy control subjects. Amygdala volume did not differ significantly between patients and controls. A significant increase in hippocampal volume was proportional to an increase in overall brain volume. These results argue against preferential involvement of medial temporal lobe structures in autism, at least in high-functioning medication-naive individuals.

Development of a Method for Reconstructing Three-dimensional Data from Axial, Sagittal, and Coronal MR Images

Magnetic resonance (MR) imaging is useful for the diagnosis of brain atrophy and intracranial abnormalities. We have developed a method of automated volumetry to evaluate the degree of brain atrophy for the diagnosis of dementia. Whole-brain MR images with thin slices without gaps are required for segmentation and volumetry. However, obtaining such images requires that the patient remain at rest for a prolonged period, thereby reducing the throughput of MR imaging examinations. Therefore, a method is needed for the reconstruction of isotropic three-dimensional (3D) data using routine axial, sagittal, and coronal MR images with 30% gaps and measurement of brain volume. The method of reconstructing 3D data consists of four processes: 1) segmentation of the brain region on axial, sagittal, and coronal MR images using the region-growing technique; 2) setting data to a 3D domain; 3) registration by manual operation; and 4) interpolation between the data based on linear interpolation. In clinical MR images, the differences between this method and the conventional technique were less than 10%. These results demonstrate that this technique is able to construct 3D data from axial, sagittal, and coronal MR images.