scholarly journals Changes in Cerebral Blood Flow during Steady-State Cycling Exercise: A Study Using Oxygen-15-Labeled Water with PET

2013 ◽  
Vol 34 (3) ◽  
pp. 389-396 ◽  
Author(s):  
Mikio Hiura ◽  
Tadashi Nariai ◽  
Kenji Ishii ◽  
Muneyuki Sakata ◽  
Keiichi Oda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Human Subjects ◽  
Insular Cortex ◽  
Cardiovascular Responses ◽  
Healthy Human ◽  
Cycling Exercise ◽  
Positron Emission ◽  
Steady State Cycling

Cerebral blood flow (CBF) during dynamic exercise has never been examined quantitatively using positron emission tomography (PET). This study investigated changes in CBF that occur over the course of a moderate, steady-state cycling exercise. Global and regional CBF (gCBF and rCBF, respectively) were measured using oxygen-15-labeled water (H215O) and PET in 10 healthy human subjects at rest (Rest), at the onset of exercise (Ex1) and at a later phase in the exercise (Ex2). At Ex1, gCBF was significantly ( P<0.01) higher (27.9%) than at Rest, and rCBF was significantly higher than at Rest in the sensorimotor cortex for the bilateral legs (M1Leg and S1Leg), supplementary motor area (SMA), cerebellar vermis, cerebellar hemispheres, and left insular cortex, with relative increases ranging from 37.6% to 70.5%. At Ex2, gCBF did not differ from Rest, and rCBF was significantly higher (25.9% to 39.7%) than at Rest in only the M1Leg, S1Leg, and vermis. The areas showing increased rCBF at Ex1 were consistent with the central command network and the anatomic pathway for interoceptive stimuli. Our results suggest that CBF increases at Ex1 in parallel with cardiovascular responses then recovers to the resting level as the steady-state exercise continues.

scholarly journals Linearization Correction of 99mTc-Labeled Hexamethyl-Propylene Amine Oxime (HM-PAO) Image in Terms of Regional CBF Distribution: Comparison to C15O2 Inhalation Steady-State Method Measured by Positron Emission Tomography

1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S52-S60 ◽  
Author(s):  
Atsushi Inugami ◽  
Iwao Kanno ◽  
Kazuo Uemura ◽  
Fumio Shishido ◽  
Matsutaro Murakami ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Emission Tomography ◽  
Emission Computed Tomography ◽  
Whole Brain ◽  
Steady State Method ◽  
Positron Emission ◽  
State Method

The radioisotope distribution following intravenous injection of 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) in the brain was measured by single photon emission computed tomography (SPECT) and corrected for the nonlinearity caused by differences in net extraction. The “linearization” correction was based on a three compartment model, and it required a region of reference to normalize the SPECT image in terms of regional cerebral blood flow distribution. Two different regions of reference, the cerebellum and the whole brain, were tested. The uncorrected and corrected HM-PAO images were compared with cerebral blood flow (CBF) image measured by the C15O2 inhalation steady state method and positron emission tomography (PET). The relationship between uncorrected HM-PAO and PET–CBF showed a correlation coefficient of 0.85 but tended to saturate at high CBF values, whereas it was improved to 0.93 after the “linearization” correction. The whole-brain normalization worked just as well as normalization using the cerebellum. This study constitutes a validation of the “linearization” correction and it suggests that after linearization the HM-PAO image may be scaled to absolute CBF by employing a global hemispheric CBF value as measured by the nontomographic 133Xe clearance method.

scholarly journals A Study of the Single Compartment Tracer Kinetic Model for the Measurement of Local Cerebral Blood Flow Using 15O-Water and Positron Emission Tomography

1987 ◽  
Vol 7 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Sanjiv S. Gambhir ◽  
Sung-Cheng Huang ◽  
Randall A. Hawkins ◽  
Michael E. Phelps
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Data Collection ◽  
Human Subjects ◽  
Compartment Model ◽  
Distribution Volume ◽  
Single Compartment ◽  
Positron Emission ◽  
Single Compartment Model ◽  
Collection Time

The effects of varying the data collection time on the calculation of cerebral blood flow and distribution volume via the integrated projection technique were studied in four human subjects. The significance of these results in terms of the limitations of the single compartment model for 15O-water was explored using computer simulations. The simulations helped to account for causes for the variations seen in blood flow and distribution volume as a function of the data collection time. Two different compartmental models were explored for better quantitation of blood flow and distribution volume.

Response of Cerebral Blood Flow and Blood Pressure to Dynamic Exercise: A Study Using PET

2018 ◽  
Vol 39 (03) ◽  
pp. 181-188 ◽  
Author(s):  
Mikio Hiura ◽  
Tadashi Nariai ◽  
Muneyuki Sakata ◽  
Akitaka Muta ◽  
Kenji Ishibashi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Stem ◽  
Cardiovascular Response ◽  
Human Subjects ◽  
Insular Cortex ◽  
Brain Regions ◽  
Dynamic Exercise ◽  
The Brain

AbstractDynamic exercise elicits fluctuations in blood pressure (BP) and cerebral blood flow (CBF). This study investigated responses in BP and CBF during cycling exercise and post-exercise hypotension (PEH) using positron emission tomography (PET). CBF was measured using oxygen-15-labeled water (H2 15O) and PET in 11 human subjects at rest (Rest), at the onset of exercise (Ex1), later in the exercise (Ex2), and during PEH. Global CBF significantly increased by 13% at Ex1 compared with Rest, but was unchanged at Ex2 and during PEH. Compared with at Rest, regional CBF (rCBF) increased at Ex1 (20~42%) in the cerebellar vermis, sensorimotor cortex for the bilateral legs (M1Leg and S1Leg), insular cortex and brain stem, but increased at Ex2 (28~31%) only in the vermis and M1Leg and S1Leg. During PEH, rCBF decreased compared with Rest (8~13%) in the cerebellum, temporal gyrus, piriform lobe, thalamus and pons. The areas showing correlations between rCBF and mean BP during exercise and PEH were consistent with the central autonomic network, including the brain stem, cerebellum, and hypothalamus (R2=0.25–0.64). The present study suggests that higher brain regions are coordinated through reflex centers in the brain stem in order to regulate the cardiovascular response to exercise.

scholarly journals Heat Acclimation Does Not Alter Cutaneous Blood Flow During Steady-state Cycling Exercise At 3500 M Altitude

2020 ◽  
Vol 52 (7S) ◽  
pp. 190-191
Author(s):  
Billie K. Alba ◽  
Katherine M. Mitchell ◽  
Karleigh E. Bradbury ◽  
Beau R. Yurkevicius ◽  
Kirsten E. Coffman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Heat Acclimation ◽  
Cutaneous Blood Flow ◽  
Cycling Exercise ◽  
Cutaneous Blood ◽  
Steady State Cycling

scholarly journals Measurement of Cerebral Blood Flow Using Bolus Inhalation of C15O2 and Positron Emission Tomography: Description of the Method and its Comparison with the C15O2 Continuous Inhalation Method

1984 ◽  
Vol 4 (2) ◽  
pp. 224-234 ◽  
Author(s):  
Iwao Kanno ◽  
Adriaan A. Lammertsma ◽  
Jon D. Heather ◽  
Jeremy M. Gibbs ◽  
Christopher G. Rhodes ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Emission Tomography ◽  
Single Breath ◽  
Steady State Method ◽  
Positron Emission ◽  
State Technique ◽  
The Difference

This article describes a rapid method for the regional measurement of cerebral blood flow using a single breath of C15O2 and positron emission tomography. The technique is based on the bolus distribution principle and utilises a reference table for the calculation of flow. Seven subjects were studied using both this method and the C15O2 continuous inhalation steady-state technique. The single-breath method gave flow values 20% higher than those obtained using the steady-state method. A simulation study was performed in an attempt to define the reasons for the difference between the two techniques. Estimations were made of identified sources of error in the measurement of regional cerebral blood flow using the single-breath technique and compared with results from a similar study previously described for the steady-state technique. However, further comparative studies will be necessary to satisfactorily explain the difference between both techniques.

Reversal of Focal Misery Perfusion after Intracranial Angioplasty: Case Report

Neurosurgery ◽  
2001 ◽  
Vol 48 (2) ◽  
pp. 436-440 ◽  
Author(s):  
Colin P. Derdeyn ◽  
DeWitte T. Cross ◽  
Christopher J. Moran ◽  
Ralph G. Dacey
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Intracranial Stenosis ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Positron Emission ◽  
Misery Perfusion ◽  
Before And After ◽  
Hemodynamic Measurements

Abstract OBJECTIVE AND IMPORTANCE The presence of reduced blood flow and increased oxygen extraction fraction (OEF) (misery perfusion) in the hemisphere distal to an occluded carotid artery is a proven risk factor for subsequent stroke. Whether angioplasty of intracranial stenosis is sufficient to reverse this condition has not been documented. CLINICAL PRESENTATION A 67-year-old man exhibited progressive right hemispheric ischemic symptoms despite maximal antiplatelet and antithrombotic therapy. Angiography demonstrated focal 80% stenosis of the supraclinoid segment of the ipsilateral internal carotid artery. TECHNIQUE 15O positron emission tomographic measurements of cerebral blood flow and OEF were made before and after transfemoral percutaneous angioplasty. OEF values measured before angioplasty were elevated in the middle cerebral artery distal to the stenosis. Angioplasty reduced the degree of luminal stenosis to 40% (linear diameter). OEF values measured 36 hours after angioplasty were normal. CONCLUSION Angioplasty of intracranial stenosis can restore normal cerebral blood flow and oxygen extraction, despite mild residual stenosis after the procedure. Hemodynamic measurements may be useful for the identification of patients with the greatest potential to benefit from angioplasty.

scholarly journals Autoregulation of Cerebral Blood Flow to Changes in Arterial Pressure in Mild Alzheimer's Disease

2010 ◽  
Vol 30 (11) ◽  
pp. 1883-1889 ◽  
Author(s):  
Allyson R Zazulia ◽  
Tom O Videen ◽  
John C Morris ◽  
William J Powers
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Pressure ◽  
The Elderly ◽  
Local Defect ◽  
Clinical Dementia Rating ◽  
Positron Emission ◽  
Before And After

Studies in transgenic mice overexpressing amyloid precursor protein (APP) demonstrate impaired autoregulation of cerebral blood flow (CBF) to changes in arterial pressure and suggest that cerebrovascular dysfunction may be critically important in the development of pathological Alzheimer's disease (AD). Given the relevance of such a finding for guiding hypertension treatment in the elderly, we assessed autoregulation in individuals with AD. Twenty persons aged 75±6 years with very mild or mild symptomatic AD (Clinical Dementia Rating 0.5 or 1.0) underwent 15O-positron emission tomography (PET) CBF measurements before and after mean arterial pressure (MAP) was lowered from 107±13 to 92±9 mm Hg with intravenous nicardipine; 11C-PIB-PET imaging and magnetic resonance imaging (MRI) were also obtained. There were no significant differences in mean CBF before and after MAP reduction in the bilateral hemispheres (−0.9±5.2 mL per 100 g per minute, P=0.4, 95% confidence interval (CI)=−3.4 to 1.5), cortical borderzones (−1.9±5.0 mL per 100 g per minute, P=0.10, 95% CI=−4.3 to 0.4), regions of T2W-MRI-defined leukoaraiosis (−0.3±4.4 mL per 100 g per minute, P=0.85, 95% CI=−3.3 to 3.9), or regions of peak 11C-PIB uptake (−2.5±7.7 mL per 100 g per minute, P=0.30, 95% CI=−7.7 to 2.7). The absence of significant change in CBF with a 10 to 15 mm Hg reduction in MAP within the normal autoregulatory range demonstrates that there is neither a generalized nor local defect of autoregulation in AD.

scholarly journals Effects of Acetazolamide on Cerebral Blood Flow, Blood Volume, and Oxygen Metabolism: A Positron Emission Tomography Study with Healthy Volunteers

2001 ◽  
Vol 21 (12) ◽  
pp. 1472-1479 ◽  
Author(s):  
Hidehiko Okazawa ◽  
Hiroshi Yamauchi ◽  
Kanji Sugimoto ◽  
Hiroshi Toyoda ◽  
Yoshihiko Kishibe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Capillary Blood ◽  
Emission Tomography ◽  
Positron Emission ◽  
Capillary Blood Volume

To evaluate changes in cerebral hemodynamics and metabolism induced by acetazolamide in healthy subjects, positron emission tomography studies for measurement of cerebral perfusion and oxygen consumption were performed. Sixteen healthy volunteers underwent positron emission tomography studies with15O-gas and water before and after intravenous administration of acetazolamide. Dynamic positron emission tomography data were acquired after bolus injection of H215O and bolus inhalation of15O2. Cerebral blood flow, metabolic rate of oxygen, and arterial-to-capillary blood volume images were calculated using the three-weighted integral method. The images of cerebral blood volume were calculated using the bolus inhalation technique of C15O. The scans for cerebral blood flow and volume and metabolic rate of oxygen after acetazolamide challenge were performed at 10, 20, and 30 minutes after drug injection. The parametric images obtained under the two conditions at baseline and after acetazolamide administration were compared. The global and regional values for cerebral blood flow and volume and arterial-to-capillary blood volume increased significantly after acetazolamide administration compared with the baseline condition, whereas no difference in metabolic rate of oxygen was observed. Acetazolamide-induced increases in both blood flow and volume in the normal brain occurred as a vasodilatory reaction of functioning vessels. The increase in arterial-to-capillary blood volume made the major contribution to the cerebral blood volume increase, indicating that the raise in cerebral blood flow during the acetazolamide challenge is closely related to arterial-to-capillary vasomotor responsiveness.

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