Regional cerebral blood flow, blood volume, oxygen extraction fraction, and oxygen utilization rate in normal volunteers measured by the autoradiographic technique and the single breath inhalation method

Abstract

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 measured by the autoradiographic method after intravenous administration of H2(15)O. Regional OEF and rCMRO2 were measured by the single inhalation of 15O2. With MR T1-weighted images as an anatomical reference, thirteen major cerebral gyri, caudate nucleus, lentiform nucleus, thalamus, midbrain, pons, cerebellum and vermis were defined on the CMRO2 images. Values were read by using circular regions of interest 16 mm in diameter. The posterior part of the cingulate gyri had the highest rCBF and rCMRO2 values among brain structures, followed by the lentiform nucleus, the cerebellum, the caudate nucleus, and the thalamus. Parahippocampal gyri had the lowest rCBF and rCMRO2 values among the cortical gyri. Regional OEF for the pontine nuclei (0.34 +/- 0.04), the midbrain (0.35 +/- 0.05), the parahippocampal gyri (0.35 +/- 0.04 for the right and 0.37 +/- 0.05 for the left), and the thalami (0.37 +/- 0.05 for the right and 0.36 +/- 0.04 for the left) were significantly lower than the mean OEF for the cerebral cortices (0.42 +/- 0.04) (p < 0.05 or less). The global CBF and CMRO2 were consistent with those obtained by the Kety-Schmidt method.(ABSTRACT TRUNCATED AT 250 WORDS)

Glutamatergic Function in the Resting Awake Human Brain is Supported by Uniformly High Oxidative Energy

“…[31][32][33][34][35] The meta-analysis was composed of CMR O2 and CMR glc values from as few as 23 and as many as 46 distinct brain areas in 109 subjects. BioImage Suite (www.…”

Rapid Quantitative Measurement of CMRO2 and CBF by Dual Administration of 15O-Labeled Oxygen and Water During a Single PET Scan—a Validation Study and Error Analysis in Anesthetized Monkeys

“…However, Iida et al (1993) have estimated the amount of recirculating water and showed that its amount can be predicted using a single compartment model in three-step ARG in normal human subjects. This method eliminates the need for plasma separation and simplifies the PET procedure (Hatazawa et al, 1995;Shidahara et al, 2002). However, as this method depends on intersubject variation of the arterial 15 O 2 TAC (which yields a bias in the CMRO 2 in DARG), its validity requires further evaluation in human studies.…”

“…An alternative autoradiographic method (ARG) using only short administration times for each of the three tracers (three-step ARG) has been developed (Mintun et al, 1984) and subsequently simplified and optimized (Iida et al, 1993;Sadato et al, 1993;Hatazawa et al, 1995;Shidahara et al, 2002;Hattori et al, 2004). Cerebral blood flow images can be obtained by an H 2 15 O autoradiographic method, using a PET counts-versus-CBF nomogram, which follows a simple look-up table procedure Herscovitch et al, 1983;Kanno et al, 1987); the quantitative accuracy of these images is improved when input delay and dispersion are corrected (Iida et al, 1986(Iida et al, , 1988.…”

Systemic circulation and cerebral oxygenation during head-up tilt in spinal cord injured individuals

“…The [HHb] increase (54 mmol×l 71 ) found in this study is very small (4 ± 6%) compared to the estimated total blood volume of approximately 70 ± 100 mmol×l 71 in the cerebrum. 24 Levine et al 25 also reported a small decrease in cerebral¯ow during orthostatic challenges in able-bodied individuals using transcranial Doppler. Although MAP and consequently cerebral perfusion pressure decreased more in SCI than AB, the [HHb] decrease was similar in both groups.…”