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Spatial normalization is an essential preprocessing step in statistical parametric mapping (SPM)-based analysis of PET scans. The standard template provided with the SPM99 software package was originally constructed using (15)O-H(2)O PET scans and is commonly applied regardless of the tracer actually used in the scans being analyzed. This work studies the(More)
BACKGROUND Ejection intraventricular pressure gradients are caused by the systolic force developed by the left ventricle (LV). By postprocessing color Doppler M-mode (CDMM) images, we can measure noninvasively the ejection intraventricular pressure difference (EIVPD) between the LV apex and the outflow tract. This study was designed to assess the value of(More)
OBJECTIVES A study of N-acetyl-aspartate (NAA) can provide data of interest about cortical alterations in psychotic illnesses. Although a decreased NAA level in the cerebral cortex is a replicated finding in chronic schizophrenia, the data are less consistent for bipolar disease. On the other hand, it is likely that NAA values in schizophrenia may differ in(More)
Schizophrenia is a heterogeneous clinical condition that may reflect a variety of biological processes. In particular, treatment-resistant (TR) schizophrenia may have a distinct neurobiological substrate. Within the context of clinical data, a simultaneous study with different imaging techniques could help to elucidate differences in cerebral substrates(More)
AIMS The aim of this study was to determine the utility of pulsed wave Doppler tissue imaging in the evaluation of regional left ventricular diastolic function in patients with ischaemic heart disease. METHODS AND RESULTS In 30 normal subjects and 43 patients with ischaemic heart disease, Doppler tissue imaging was performed in each of the 16 segments of(More)
BACKGROUND Diastolic suction is a major determinant of early left ventricular filling in animal experiments. However, suction remains incompletely characterized in the clinical setting. METHODS AND RESULTS First, we validated a method for measuring the spatio-temporal distributions of diastolic intraventricular pressure gradients and differences (DIVPDs)(More)
OBJECTIVE Food intake is regulated by factors that modulate caloric requirements as well as food's reinforcing properties. In this study, we measured brain glucose utilization to an olfactory stimulus (bacon scent), and we examined the role of food restriction and genetic predisposition to obesity on such brain metabolic activity. METHODS Zucker obese(More)
Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image(More)
BACKGROUND Decreased metabolic activity in the prefrontal cortex during cognitive activation is a recurrent finding and a likely functional marker of schizophrenia. AIMS To investigate the occurrence of hypofrontality in patients with first-episode psychosis, with or without evolution to schizophrenia. METHOD We used fluorodeoxyglucose positron emission(More)