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Background: Understanding the influence of aging on the brain remains a challenge in determining its role as a risk factor for Alzheimer's disease.Objective: To identify patterns of aging in a large neuroimaging cohort.Methods: A large psychiatric cohort of 31,227 individuals received brain SPECT at rest and during a concentration task for a total of 62,454 scans. ANOVA was done to identify the mean age trends over the course of the age range in this group, 0-105 years. A regression model in which brain SPECT regions of interest was used to predict chronological age (CA) was then utilized to derive brain estimated age (BEA). The difference between CA and BEA was calculated to determine increased brain aging in common disorders in our sample such as depression, dementia, substance use, and anxiety.Results: Throughout the lifespan, variations in perfusion were observed in childhood, adolescence, and late life. Increased brain aging was seen in alcohol use, cannabis use, anxiety, bipolar, schizophrenia, attention-deficit/hyperactivity disorder, and in men.Conclusion: Brain SPECT can predict chronological age and this feature varies as a function of common psychiatric disorders. [ABSTRACT FROM AUTHOR]

Background: Depression remains an important risk factor for Alzheimer's disease, yet few neuroimaging biomarkers are available to identify treatment response in depression.Objective: To analyze and compare functional perfusion neuroimaging in persons with treatment resistant depression (TRD) compared to those experiencing full remission.Methods: A total of 951 subjects from a community psychiatry cohort were scanned with perfusion single photon emission computed tomography (SPECT) of the brain in both resting and task related settings. Of these, 78% experienced either full remission (n = 506) or partial remission (n = 237) and 11% were minimally responsive (n = 103) or non-responsive (11%. n = 106). Severity of depression symptoms were used to define these groups with changes in the Beck Depression Inventory prior to and following treatment. Voxel-based analyses of brain SPECT images from full remission compared to the worsening group was conducted with the statistical parametric mapping software, version 8 (SPM 8). Multiple comparisons were accounted for with a false discovery rate (p < 0.001).Results: Persons with depression that worsened following treatment had reduced cerebral perfusion compared to full remission in the multiple regions including the bilateral frontal lobes, right hippocampus, left precuneus, and cerebellar vermis. Such differences were observed on both resting and concentration SPECT scans.Conclusion: Our findings identify imaging-based biomarkers in persons with depression related to treatment response. These findings have implications in understanding both depression to prognosis and its role as a risk factor for dementia. [ABSTRACT FROM AUTHOR]

Introduction: Meningioma is usually a benign brain tumor, but sometimes with aggressive course. The aim of this study was to assess the ability of 201Tl Brain SPECT to differentiate the pathologic grade of meningioma preoperatively. Methods: Thirty lesions in 28 patients were evaluated in this study. Early (20 minutes) and late (3 hours) brain SPECT images were performed and early uptake ratio (EUR), late uptake ratio (LUR) and retention index (RI) were calculated. All patients were operated and pathologic grade of tumors were defined according to World Health Organization grading system. Results: SPECT results were compared in different pathologic groups. Data analysis clarified no significant difference of EUR in benign and aggressive meningioma (P=0.2). However LUR and RI were significantly higher in aggressive tumors (P=0.001 and P=0.02, respectively). Conclusion: According to our data Tl-201 Brain SPECT with early and late imaging has 80% sensitivity and specificity to differentiate malignant from benign meningioma. [ABSTRACT FROM AUTHOR]

Background: There is a range of factors that predict the development of Alzheimer's disease (AD) dementia among patients with amnestic mild cognitive impairment (MCI). Objectives: To identify the neuropsychological, genetic, and functional brain imaging data that best predict conversion to AD dementia in patients with amnestic MCI. Methods: From an initial group of 42 amnestic MCI patients assessed with neurological, neuropsychological, and brain SPECT, 39 (25 converters, 14 non-converters) were followed for 4 years, and 36 had APOE ε4 genotyping. Baseline neuropsychological data and brain SPECT data were used to predict which of the MCI patients would develop dementia by the end of the 4 years of observation. Results: The MCI patients who had converted to AD dementia had poorer performance on long-term visual memory and Semantic Fluency tests. The MCI subjects who developed dementia were more likely to carry at least one copy of the APOE ε4 allele (Hazard Risk = 4.22). There was lower brain perfusion in converters than non-converters, mainly in postcentral gyrus. An additional analysis of the SPECT data found differences between the MCI subjects and controls in the posterior cingulate gyrus and the basal forebrain. When the brain imaging and neuropsychological test data were combined in the same Cox regression model, only the neuropsychological test data were significantly associated with time to dementia. Conclusion: Although the presence of reduced brain perfusion in postcentral gyrus and basal forebrain indicated an at-risk condition, it was the extent of memory impairment that was linked to the speed of decline from MCI to AD. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the utility of a new multimodal image-guided intervention technique to detect epileptogenic areas with a gamma probe as compared with intraoperative electrocorticography. Materials and Methods: Two symptomatic patients with refractory epilepsy underwent magnetic resonance imaging, videoelectroencephalography, brain SPECT scan, neuropsychological evaluation and were submitted to gamma probe-assisted surgery. Results: In patient 1, maximum radioactive count was initially observed on the temporal gyrus at about 3.5 cm posteriorly to the tip of the left temporal lobe. After corticotomy, the gamma probe indicated maximum count at the head of the hippocampus, in agreement with the findings of intraoperative electrocorticography. In patient 2, maximum count was observed in the occipital region at the transition between the temporal and parietal lobes (right hemisphere). During the surgery, the area of epileptogenic activity mapped at electrocorticography was also delimited, demarcated, and compared with the gamma probe findings. After lesionectomy, new radioactive counts were performed both in the patients and on the surgical specimens (ex-vivo). Conclusion: The comparison between intraoperative electrocorticography and gamma probe-assisted surgery showed similarity of both methods. The advantages of gamma probe include: noninvasiveness, low cost and capacity to demonstrate decrease in the radioactive activity at the site of excision after lesionectomy. [ABSTRACT FROM AUTHOR]

Brain SPECT imaging is a nuclear medicine study that uses isotopes bound to neurospecific pharmaceuticals to evaluate regional cerebral blood flow (rCBF) and indirectly metabolic activity. With current available technology and knowledge SPECT has the potential to add important clinical information to benefit patient care in many different areas of a substance abuse practice, including in the area of process addictions. This article explores the ways brain SPECT has the potential to be useful to clinicians in helping to understand and direct treatment for complex cases of obesity and sexual addictions. Areas where SPECT can add value include helping clinicians ask better questions, helping them in making more complete diagnoses, evaluating underlying brain systems pathology, decreasing stigma and increasing compliance, and visualizing effectiveness via follow-up evaluations. In particular, SPECT can help in identifying and assessing the issue of brain trauma and toxicity in process addictions, which may be significant contributing factors in treatment failure. Three illustrative case histories will be given. [ABSTRACT FROM AUTHOR]

The difficulties encountered in regards to defining the diagnosis of patients with an Eating Behavior Disorder (EBD) have favored the use of multidimensional models. This study has aimed to identify which psychopathological and neurobiological variables could have a discriminating capacity regarding the different EBD diagnostic subtypes. A total of 42 patients with an EBD diagnosis (11 Restrictive Anorexia (R-AN), 10 Purgative Anorexia (P-AN), 7 Non-purgative Bulimia (NP-BN), 14 Purgative Bulimia (P-BN)), according to DSM-IV criteria, were selected from those who came for treatment in the Ciudad Real General Hospital Eating Disorder Unit. Twelve healthy controls were also included. All of the subjects underwent a brain SPECT to measure regional cerebral blood flow (rCBF) in baseline situation (rest). A second one was performed after a visual neutral stimulus (sight of a calm sea) and another one after confronting them with their own corporal image, filmed two weeks before. A battery of questionnaires was administered to evaluate general and eating psychopathology. Patients with NP-BN showed less eating and general psychopathology. Furthermore, unlike patients with R-AN and P-BN, they did not experience an increase of the rCBF when confronted with their own body image. Discriminant variables were body dissatisfaction measured with the BSQ, BMI; BITE scores, ideal silhouette scores, and temporal right hyperactivation when they were shown their own body image. The subgroup of patients diagnosed with NP-BN showed less emotional alteration and less emotional response when they were shown their own body image than the rest of patients with EBD. These differences might have implications from the therapeutic, prognostic or even taxonomic viewpoint. [ABSTRACT FROM AUTHOR]

Background: Moyamoya disease is a rare, progressive cerebrovascular disorder caused by intracranial stenosis of the circle of Willis, resulting in successive ischemic events. Computed tomography (CT) and magnetic resonance imaging (MRI) play a major role in diagnosis. Objective: The aim of the study was to describe the spectrum of findings on brain SPECT in patients with Moyamoya disease and to compare the findings with other investigations. Materials and Methods: Tc99m-ECD SPECT scans of seventeen patients (7 children and 10 adults) were analysed to study the brain perfusion. Results: Features of Moyamoya disease were detected on DSA in 11 patients, CTA in one, MR angiography in one patient. Brain perfusion SPECT analysis showed unilateral perfusion defects in 11 patients, normal perfusion in 2 and bilateral defects in 4 patients. No perfusion defects despite bilateral vascular changes were noted in one patient. Cerebral infarcts were detected on MRI unilaterally in three subjects while multiple infarcts were identified in one. Tc99m-ECD Brain SPECT showed perfusion defects that were more extensive compared to those detected on MRI. Post acetazolamide studies for assessment of cerebrovascular reserve were done in three patients. Two of them showed good cerebrovascular reserve (>1). Follow-up studies post-surgical procedures (Myo-dura synangiosis) done in two patients showed partial resolution of perfusion defects in the involved areas. Conclusion: Brain perfusion scintigraphy is an important adjunct in evaluation of patients with Moyamoya disease yielding information about the direct end results of the pathology in the vessels and also prognostic information. [ABSTRACT FROM AUTHOR]

Objective: Posterior cortical atrophy (PCA) is a rare dementia syndrome that presents primarily with signs of cortical visual dysfunction. The main clinical features of the disease include Balint's syndrome, Gerstmann's syndrome, visual agnosia, alexia, agraphia, and transcortical sensory aphasia. In this study, we aimed to determine the clinical characteristics and the brain single proton emission computed tomography (SPECT) findings of patients clinically diagnosed as having PCA. Methods: The subjects followed in the dementia outpatient clinic of neurology department, Dokuz Eylül University Hospital, suspected to have PCA and who have undergone cognitive testing and brain SPECT inspection were included in the study. Records of a total of 1105 subjects were screened and among them, nine patients who were clinically thought to have PCA were reached. Results: The presenile age onset, more prominent loss of visuospatial abilities than amnestic feature, early detection of visual agnosia, comorbidity of depression and apraxia in early term, fluent speech are among the symptoms that preoccupy PCA. Brain SPECT is a useful examination method in patients suspected to have PCA. Patients with hypoperfusion in the posterior brain regions also must be taken into account in terms of recognizing clinical features of PCA. Conclusion: The mean age of the subjects was 59.11±4.1 years, onset of the disease was 55.83±4.97 years and all patients were female. Eight cases had Gerstmann's syndrome with all components, whereas in seven of them simultanagnosia was established. They had severe visual memory defect, which was more prominent than verbal memory defect. Visual-spatial functions were extremely deteriorated in all patients. Figure copying was severely worsened in all patients. Clock drawing was either not accomplished or was severely bad. Eight patients had ideomotor apraxia. Speech was fluent in all patients. Eight patients had depression that simultaneously developed with the onset of the complaints. Brain SPECT revealed either unilateral or bilateral hypoperfusion in the posterior temporal, parietal or occipital lobes. (Archives of Neuropsychiatry 2010; 47: 201-6) [ABSTRACT FROM AUTHOR]

Summary: Objective: Alzheimer''s disease (AD) and frontotemporal dementia (FTD) are among the most frequent neurodegenerative cognitive disorders, but their differential diagnosis is difficult. The aim of this study was to evaluate an automatic method returning the probability that a patient suffers from AD or FTD from the analysis of brain perfusion single photon emission computed tomography images. Methods and materials: A set of 116 descriptors corresponding to the average activity in regions of interest was calculated from the images of 82 AD and 91 FTD patients. A set of linear (logistic regression and linear discriminant analysis) and non-linear (support vector machines, k-nearest neighbours, multilayer perceptron and kernel logistic PLS) classification methods was subsequently used to ascertain diagnoses. Validation was carried out by means of the leave-one-out protocol. Diagnoses by the classifier and by four physicians (visual assessment) were compared. Since images were acquired in different hospitals, the impact of the medical centre on the diagnosis of both the classifier and the physicians was investigated. Results: Best results were obtained with support vector machine and partial least squares regression coupled with k-nearest neighbours methods (PLS+K-NN), with an overall accuracy of 88%. PLS+K-NN was however considered as the best method since performances obtained with leave-one-out cross-validation were closer to whole-database learning. The performances of the classifier were higher than those of experts (accuracy ranged from 65 to 72%). Physicians found it more difficult to diagnose the images from centres other than their own, and it affected their performances. Conclusions: The performances obtained by the classifier for the differential diagnosis of AD and FTD were found convincing. It could help physicians in daily practice, particularly when visual assessment is inconclusive, or when dealing with multicentre data. [Copyright &y& Elsevier]

In this study related to human brain SPECT imaging, simulation of half-cone-beam (HCB) collimation with different scan paths is performed and compared with simulated fan-beam and parallel-hole circular orbit acquisitions of disk-phantom projection data. Acquisition types are quantitatively evaluated based on the photon detection efficiency, the root-mean-squared error, contrast and signal-to-noise ratio measurements of the reconstructed images. We demonstrate that a triple-camera SPECT system with half-cone-beam collimators and circle-and-helix scan paths can offer up to a 26% efficiency increase over fan-beam, and up to a 128% increase over parallel-hole collimators for equal spatial resolutions, and display no visible axial sampling artifacts in reconstructed disk-phantom images. In addition, we perform qualitative experimental evaluation of triple-HCB circle-and-helix acquisition using a Hoffman 3D brain phantom. Reconstructed brain phantom images show improved quality due to reduced noise and no apparent sampling artifacts. Triple-HCB circle-and-helix SPECT has a potential for improved brain imaging, producing higher image quality with a smaller reconstruction error and better lesion detectability due to increased efficiency for equal spatial resolution compared to conventional fan-beam and parallel-hole SPECT. [ABSTRACT FROM AUTHOR]