Learn More
Regional cerebral blood flow (CBF), oxygen extraction ratio (OER), oxygen utilization (CMRO2) and blood volume (CBV) were measured in a group of 34 healthy volunteers (age range 22-82 yrs) using the 15O steady-state inhalation method and positron emission tomography. Between subjects CBF correlated positively with CMRO2, although the interindividual(More)
Hypercapnia induces cerebral vasodilation and increases cerebral blood flow (CBF), and hypocapnia induces cerebral vasoconstriction and decreases CBF. The relation between changes in CBF and cerebral blood volume (CBV) during hypercapnia and hypocapnia in humans, however, is not clear. Both CBF and CBV were measured at rest and during hypercapnia and(More)
By means of a high resolution PET scanner, the regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction fraction (rOEF), and metabolic rate of oxygen (rCMRO2) for major cerebral gyri and deep brain structures were studied in eleven normal volunteers during an eye-covered and ear-unplugged resting condition. Regional CBF was(More)
Hypercapnia and hypocapnia produce cerebral vasodilation and vasoconstriction, respectively. However, regional differences in the vascular response to changes in Paco2 in the human brain are not pronounced. In the current study, these regional differences were evaluated. In each of the 11 healthy subjects, cerebral blood flow (CBF) was measured using(More)
The hemodynamic mechanism of increase in cerebral blood flow (CBF) during neural activation has not been elucidated in humans. In the current study, changes in both regional CBF and cerebral blood volume (CBV) during visual stimulation in humans were investigated. Cerebral blood flow and CBV were measured by positron emission tomography using H(2)(15)O and(More)
UNLABELLED Measurement of the arterial input function is essential for quantitative assessment of physiological function in vivo using PET. However, frequent arterial blood sampling is invasive and labor intensive. Recently, a PET system has been developed that consists of two independent PET tomographs for simultaneously scanning the brain and heart, which(More)
The novel muscarinic cholinergic ligands (+)N-[11C]methyl-3-piperidyl benzilate ([11C](+)3-MPB) and its stereoisomer [11C](-)3-MPB were evaluated in comparison with [11C]4-MPB in the brains of conscious monkeys (Macaca mulatta) using high-resolution positron emission tomography (PET). The regional distribution patterns of [11C](+)3-MPB and [11C]4-MPB at(More)
We compared neural activation detected by magnetoencephalography (MEG) during tactile presentation of words and non-words in a postlingually deaf-blind subject and six normal volunteers. The left postcentral gyrus, bilateral inferior frontal gyri, left posterior temporal lobe, right anterior temporal lobe, bilateral middle occipital gyri were activated when(More)
PURPOSE To evaluate the differences between fludeoxyglucose F 18 (FDG) and L-methyl-11C-methionine (11C-methionine) as tracers for positron emission tomography (PET) in the evaluation of brain tumors. METHODS We analyzed 10 patients with histologically verified cerebral glioma or meningioma and 1 patient with a neuroradiologic diagnosis of low-grade(More)
Fourteen patients with cerebral gliomas were studied with positron emission tomography (PET) using L-[methyl-11C]methionine (11C-MET). Positive images of tumour were obtained in all cases regardless of histological grades. The analysis of differential absorption ratio (DAR) showed the higher accumulation of 11C-MET in high grade gliomas than in low grade(More)