PubMed Health⌕ Search

Biomedical subjects

E Sveinsdottir

Publications and source records attributed to E Sveinsdottir.

9 recordsLinked to original sources
PubMed1977

A multidetector scintillation camera with 254 channels.

A computer-based scintillation camera has been designed for both dynamic and static radionuclide studies. The detecting head has 254 independent sodium iodide crystals, each with a photomultiplier and amplifier. In dynamic measurements simultaneous events can be recorded, and 1 million total counts per second can be accommodated with less than 0.5% loss in any one channel. This corresponds to a calculated deadtime of 5 nsec. The multidetector camera is being used for 133Xe dynamic studies of regional cerebral blood flow in man and for 99mTc and 197 Hg static imaging of the brain.

Brain Neoplasms↗
PubMed1976

Regional cerebral blood flow in focal cortical epilepsy.

Regional cerebral blood flow (rCBF) was studied in ten patients with focal cortical epilepsy. The blood flow was measured by the intra-arterial injection of xenon 133 (133Xe), and the isotope clearance was recorded by a multidetector scintillation camera with 254 detectors. Three patients were studied both during a seizure and (in the same setting) in the interictal period; six patients were studied only in the interictal period, and one patient was studied only during a seizure. Studies during seizures all showed marked flow increases in areas presumed to participate in the seizure activity. This finding accords with earlier studies. All nine patients studied in the interictal phase showed, either spontaneously or during activation by intermittent light, focal flow increases in areas presumed to comprise the epileptic focus. These interictal hyperemic foci probably reflect subictal neuronal hyperactivity in epileptogenic nervous tissue. Only two of the patients had distinct epileptic electroencephalographic foci. It appears that rCBF studies can be a valuable diagnostic tool in the investigation of cortical epileptogenic lesions.

Adult↗