scholarly journals A New Proposal of an Index for Regional Cerebral Perfusion Pressure - A Theoretical Approach with Fluid Dynamics

2021 ◽  
Author(s):  
Masashi Kameyama ◽  
Toshimitsu Momose
Keyword(s):  
Fluid Dynamics ◽  
Positron Emission Tomography ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Theoretical Background ◽  
Emission Tomography ◽  
Positron Emission ◽  
Poiseuille Equation

Cerebral blood flow (CBF) / cerebral blood volume (CBV) ratio derived by [15O] H2O/ CO2 and CO positron emission tomography (PET) examination has been used empirically as an index for cerebral perfusion pressure (CPP). However, it lacks theoretical background and could not be confirmed to be proportionate to CPP, as measurement of local CPP is not practical. We have developed a new index for CPP from Poiseuille equation based on a simple model. Our model implies that CBF/CBV2 is proportionate to CPP. To estimate CPP, CBF/CBV2 would be a preferable index to CBF/CBV theoretically.

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.

Management of raised intracranial pressure

2020 ◽  
pp. 3892-3897
Author(s):  
David K. Menon
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Brain Oedema ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Brain Perfusion ◽  
Normal Brain ◽  
Intracranial Volume ◽  
Nervous System Diseases

Normal intracranial pressure is between 5 and 15 mm Hg in supine subjects. Intracranial hypertension (ICP >20 mm Hg) is common in many central nervous system diseases and in fatal cases is often the immediate cause of death. Increases in intracranial volume and hence—given the rigid skull—intracranial pressure may be the consequence of brain oedema, increased cerebral blood volume, hydrocephalus, and space-occupying lesions. Brain perfusion depends on the cerebral perfusion pressure which is mean arterial pressure minus intracranial pressure. The normal brain autoregulates cerebral blood flow down to a lower limit of cerebral perfusion pressure of about 50 mm Hg in healthy subjects, and perhaps 60–70 mm Hg in disease. Cerebral perfusion pressure reduction to below these values results in cerebral ischaemia.

Positron emission tomography in ischaemic stroke: cerebral perfusion and metabolism after stroke onset

1998 ◽  
Vol 5 (4) ◽  
pp. 413-416 ◽  
Author(s):  
Masahiro Yasaka ◽  
Stephen J Read ◽  
Graeme J O'Keefe ◽  
Gary F Egan ◽  
Owen Pointon ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Ischaemic Stroke ◽  
Cerebral Perfusion ◽  
Stroke Onset ◽  
Emission Tomography ◽  
Positron Emission

Effects of graded hypotension on cerebral blood flow, blood volume, and mean transit time in dogs

1992 ◽  
Vol 262 (6) ◽  
pp. H1908-H1914 ◽  
Author(s):  
M. Ferrari ◽  
D. A. Wilson ◽  
D. F. Hanley ◽  
R. J. Traystman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Perfusion Pressure ◽  
Blood Volume ◽  
Transit Time ◽  
Cerebral Perfusion ◽  
Pressure Range ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Mean Transit Time

This study tested the hypothesis that cerebral blood flow (CBF) is maintained by vasodilation, which manifests itself as a progressive increase in mean transit time (MTT) and cerebral blood volume (CBV) when cerebral perfusion pressure is reduced. Cerebral perfusion pressure was decreased in 10 pentobarbital-anesthetized dogs by controlled hemorrhage. Microsphere-determined CBF was autoregulated in all tested cerebral regions over the 40- to 130-mmHg cerebral perfusion pressure range but decreased by 50% at approximately 30 mmHg. MTT and CBV progressively and proportionately increased in the right parietal cerebral cortex over the 40- to 130-mmHg cerebral perfusion pressure range. Total hemoglobin content (Hb1), measured in the same area by an optical method, increased in parallel with the increases in CBV computed as the (CBF.MTT) product. At 30 mmHg cerebral perfusion pressure, CBV and Hb were still increased and MTT was disproportionately lengthened (690% of control). We conclude that within the autoregulatory range, CBF constancy is maintained by both increased CBV and MTT. Outside the autoregulatory range, substantial prolongation of the MTT occurs. When CBV is maximal, further reductions in cerebral perfusion pressure produce disproportionate increases in MTT that signal the loss of cerebral vascular dilatory hemodynamic reserve.

scholarly journals In vivo Measurement of Regional Cerebral Haematocrit Using Positron Emission Tomography

1984 ◽  
Vol 4 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Adriaan A. Lammertsma ◽  
David J. Brooks ◽  
Ronald P. Beaney ◽  
David R. Turton ◽  
Malcolm J. Kensett ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Mean Value ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
In Vivo Measurement ◽  
Positron Emission ◽  
Regional Cerebral Blood Volume

A method is described for measuring the regional cerebral-to-large vessel haematocrit ratio using inhalation of carbon-11-labelled carbon monoxide and the intravenous injection of carbon-11-labelled methyl-albumin in combination with positron emission tomography. The mean value in a series of nine subjects was 0.69. This is ∼20% lower than the value of 0.85 previously reported. It is concluded that previous measurements of regional cerebral blood volume using a haematocrit ratio of 0.85 will have underestimated the value of regional cerebral blood volume by 20%.

Effects of increased intracranial pressure on cerebral blood volume, blood flow, and oxygen utilization in monkeys

1975 ◽  
Vol 43 (4) ◽  
pp. 385-398 ◽  
Author(s):  
Robert L. Grubb ◽  
Marcus E. Raichle ◽  
Michael E. Phelps ◽  
Robert A. Ratcheson
Keyword(s):  
Blood Flow ◽  
Intracranial Pressure ◽  
Metabolic Rate ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Blood Volume ◽  
Cerebral Perfusion ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Cerebral Metabolic Rate

✓ The relationship of cerebral blood volume (CBV) to cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and the cerebral metabolic rate for oxygen (CMRO2) was examined in rhesus monkeys. In vivo tracer methods employing radioactive oxygen-15 were used to measure CBV, CBF, and CMRO2. Cerebral perfusion pressure was decreased by raising the intracranial pressure (ICP) by infusion of artificial cerebrospinal fluid (CSF) into the cisterna magna. The production of progressive intracranial hypertension to an ICP of 70 torr (CPP of 40 torr) caused a rise in CBV accompanied by a steady CBF. With a further increase in ICP to 94 torr, CBV remained elevated without change while CBF declined significantly. Cerebral metabolic rate for oxygen did not change significantly during intracranial hypertension. For comparison, CPP was lowered by reducing mean arterial blood pressure in a second group of monkeys. Only CBF was measured in this group. In this second group of animals, the lower limit of CBF autoregulation was reached at a higher CPP (CPP ∼ 80 torr) than when an increase in ICP was employed (CPP ∼ 30 torr).

scholarly journals Validation of VASO cerebral blood volume measurement with positron emission tomography

2010 ◽  
Vol 65 (3) ◽  
pp. 744-749 ◽  
Author(s):  
Jinsoo Uh ◽  
Ai-Ling Lin ◽  
Kihak Lee ◽  
Peiying Liu ◽  
Peter Fox ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Volume Measurement ◽  
Emission Tomography ◽  
Positron Emission ◽  
Blood Volume Measurement

Positron Emission Tomographic Studies on Cerebral Hemodynamics in Patients with Cerebral Contusion

Neurosurgery ◽  
1990 ◽  
Vol 26 (6) ◽  
pp. 971-979 ◽  
Author(s):  
Hiroshi Tenjin ◽  
Satoshi Ueda ◽  
Norihiko Mizukawa ◽  
Yoshio Imahori ◽  
Akihiko Hino ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Cerebral Blood Volume ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Cerebral Contusion ◽  
Chronic Stage ◽  
Positron Emission ◽  
Regional Cerebral Blood Volume

Abstract Positron emission tomography is currently one of the most useful methods for measurements of cerebral hemodynamics and oxygen metabolism, because it facilitates accurate analysis of the local cerebral circulation in three-dimensional quantitative images. In this study, we performed positron emission tomography studies to measure cerebral circulation in a total of 11 patients who sustained head injuries with contusion. Several parameters were measured including regional cerebral blood flow, regional cerebral blood volume, permeability, and regional cerebral metabolic rate for oxygen. Data from brains both with and without contusion were analyzed for chronological changes, in the subacute stage from the 8th to 29th day and in the chronic stage until 360 days after the injury and compared with similar data in a group of normal subjects. It was concluded that in the subacute stage, regional cerebral blood flow decreased (26 ± 7 and 39 ± 10 ml/100 g/min) and regional cerebral blood volume increased (5.6 ± 1.8 and 5.4 ± 0.9 ml/100 g) both in areas of cerebral contusion and in areas remote from cerebral contusion and that permeability increased in areas of contusion but not in remote brain areas. In the chronic stage, these parameters showed a tendency for recovery.

scholarly journals Intravoxel incoherent motion perfusion in patients with Moyamoya disease: comparison with 15O-gas positron emission tomography

2019 ◽  
Vol 8 (5) ◽  
pp. 205846011984658
Author(s):  
Shoko Hara ◽  
Masaaki Hori ◽  
Ryo Ueda ◽  
Akifumi Hagiwara ◽  
Shihori Hayashi ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
White Matter ◽  
Moyamoya Disease ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Emission Tomography ◽  
Intravoxel Incoherent Motion ◽  
Healthy Controls ◽  
Diffusion Weighted Images ◽  
Positron Emission

Background Intravoxel incoherent motion magnetic resonance imaging (IVIM) enables non-invasive measurement of brain perfusion. Purpose To investigate whether IVIM could be used to evaluate the hemodynamic disturbance of Moyamoya disease (MMD) by comparison with the gold-standard 15O-gas positron emission tomography (PET) method. Material and Methods Ten consecutive patients with MMD (six women; mean age = 42.8 years) and 10 age-matched healthy controls were evaluated by diffusion-weighted images with 12 different b values in the range of 0–900 s/mm2 and 15O-gas PET. Tomographic maps of IVIM parameters, perfusion fraction ( f ), pseudo-diffusion coefficient ( D*), and f・D*, as well as cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps obtained with PET, were normalized and hemispheric gray and white matter values were calculated. IVIM parametric values were compared with PET parameters and with clinically assessed disease severity. Results There was significant correlation between D* and MTT ( r = –0.74, P < 0.001) and between f・D* and CBF ( r = 0.52, P = 0.02) in the cortical areas. The f values in the white matter were significantly higher in symptomatic MMD patients than in healthy controls ( P = 0.01). Conclusion IVIM may be used to non-invasively investigate cerebral hemodynamic impairment in patients with MMD. Further evaluation is needed to establish IVIM usage in clinical settings.

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