Positron emission tomography study of regional cerebral metabolism during general anesthesia with xenon in humans.

Background: The precise mechanism by which the gaseous anesthetic xenon exerts its effects in the human brain remains unknown. Xenon has only negligible effects on inhibitory gamma-aminobutyric acid receptors, one of the putative molecular targets for most general anesthetics. Instead, xenon has been suggested to induce anesthesia by inhibiting excitatory glutamatergic signaling.

Preoperative mapping of cortical language areas in adult brain tumour patients using PET and individual non-normalised SPM analyses.

In patients scheduled for the resection of perisylvian brain tumours, knowledge of the cortical topography of language functions is crucial in order to avoid neurological deficits. We investigated the applicability of statistical parametric mapping (SPM) without stereotactic normalisation for individual preoperative language function brain mapping using positron emission tomography (PET). Seven right-handed adult patients with left-sided brain tumours (six frontal and one temporal) underwent 12 oxygen-15 labelled water PET scans during overt verb generation and rest.

Thyroid volume measurement in patients prior to radioiodine therapy: comparison between three-dimensional magnetic resonance imaging and ultrasonography.

Because of its cost effectiveness, wide availability, and technical ease of application, ultrasonography is the reference method for determining the thyroid volume prior to radioiodine therapy. The goal of the study is a prospective assessment of the deviation between volumetric ultrasonography measurements in comparison to those performed with three-dimensional magnetic resonance imaging (MRI). To that end, 60 consecutive patients with multinodular toxic goiter (n = 28, 46.

Cerebral correlates of selective attention in schizophrenic patients with formal thought disorder: a controlled H2 15O-PET study.

There is a widespread belief that formal thought disorders may be associated with disturbed selective attention in schizophrenia. Two hypotheses are derived: (1) patients with slightly pronounced formal thought disorders should differ from those with severely expressed formal thought disorders in terms of selective attention; and (2) the cerebral correlates of selective attention should be organised differently in mildly versus severely thought-disordered patients. We compared 20 female schizophrenic patients, one-half with mild, one-half with obvious formal thought disorders, and 10 control subjects on a neuropsychological battery and a cognitive activation task for selective attention (Go/NoGo) for the assessment of rCBF using H2 15O-PET.