scholarly journals Differences in Hemodynamic Alteration between Atherosclerotic Occlusive Lesions and Moyamoya Disease: A Quantitative 15O-PET Study

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1820
Author(s):  
Chiaki Igarashi ◽  
Hidehiko Okazawa ◽  
Muhammad M. Islam ◽  
Tetsuya Tsujikawa ◽  
Toshifumi Higashino ◽  
...  
Keyword(s):  
Blood Volume ◽  
Challenge Test ◽  
Compartment Model ◽  
Cerebrovascular Reactivity ◽  
Oxygen Extraction Fraction ◽  
Hemodynamic Parameters ◽  
Arterial Perfusion ◽  
Hemodynamic Status ◽  
Weighted Integral ◽  
Capillary Blood Volume

To clarify the differences in hemodynamic status between atherosclerotic steno-occlusive lesions (SOL) and moyamoaya disease (MMD), hemodynamic parameters were compared using 15O-PET. Twenty-four patients with unilateral SOL (67 ± 11 y) and eighteen with MMD (33 ± 16 y) were assigned to this study. MMD patients were divided into twelve unilateral and six bilateral lesions. All patients underwent 15O-PET to measure cerebral blood flow (CBF), blood volume (CBV), oxygen extraction fraction (OEF), and metabolic rate (CMRO2). Acetazolamide was administered after the baseline scan and the second 15O-water PET was performed to evaluate cerebrovascular reactivity (CVR). For the CBF calculation in 15O-water PET, the three-weighted integral method was applied based on a one-tissue compartment model with pixel-by-pixel delay correction to measure precise CBF and arterial-to-capillary blood volume (V0). Baseline hemodynamic parameters showed significantly lower CBF, V0, and CMRO2, but greater CBV, OEF, and delay (p < 0.01) in the affected hemispheres than in the unaffected hemispheres. After ACZ administration, both hemispheres showed a significant increase in CBF (p < 0.0001), but not in V0. CVR differed significantly between the hemispheres. The arterial perfusion pressure of the functioning arterial part tended to be reduced after acetazolamide administration in patients with past neurologic events caused by hemodynamic impairment. MMD patients showed greater inactive vascular and venous volumes compared with common atherosclerotic SOL patients. The hemodynamic status of cerebral circulation may vary according to the chronic process of steno-occlusive change and the development of collateral circulation. In order to evaluate physiologic differences between the two diseases, 15O-PET with an acetazolamide challenge test is useful.

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.

Effect of Thrombolytic Therapy on Pulmonary-Capillary Blood Volume in Patients with Pulmonary Embolism

1980 ◽  
Vol 303 (15) ◽  
pp. 842-845 ◽  
Author(s):  
G. V. R. K. Sharma ◽  
Virginia A. Burleson ◽  
Arthur A. Sasahara ◽  
Barbara Roggeveen ◽  
Nazarene Mondello ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Thrombolytic Therapy ◽  
Blood Volume ◽  
Capillary Blood ◽  
Pulmonary Capillary ◽  
Capillary Blood Volume ◽  
Pulmonary Capillary Blood ◽  
Pulmonary Capillary Blood Volume

scholarly journals Hemodynamic and metabolic changes during hypercapnia with normoxia and hyperoxia using pCASL and TRUST MRI in healthy adults

2021 ◽  
pp. 0271678X2110645
Author(s):  
Pieter T Deckers ◽  
Alex A Bhogal ◽  
Mathijs BJ Dijsselhof ◽  
Carlos C Faraco ◽  
Peiying Liu ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
Oxygen Metabolism ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Oxygen Extraction Fraction ◽  
Mixed Effect ◽  
Cerebral Oxygen Metabolism ◽  
Extraction Fraction ◽  
Oxygenation Level

Blood oxygenation level-dependent (BOLD) or arterial spin labeling (ASL) MRI with hypercapnic stimuli allow for measuring cerebrovascular reactivity (CVR). Hypercapnic stimuli are also employed in calibrated BOLD functional MRI for quantifying neuronally-evoked changes in cerebral oxygen metabolism (CMRO2). It is often assumed that hypercapnic stimuli (with or without hyperoxia) are iso-metabolic; increasing arterial CO2 or O2 does not affect CMRO2. We evaluated the null hypothesis that two common hypercapnic stimuli, ‘CO2 in air’ and carbogen, are iso-metabolic. TRUST and ASL MRI were used to measure the cerebral venous oxygenation and cerebral blood flow (CBF), from which the oxygen extraction fraction (OEF) and CMRO2 were calculated for room-air, ‘CO2 in air’ and carbogen. As expected, CBF significantly increased (9.9% ± 9.3% and 12.1% ± 8.8% for ‘CO2 in air’ and carbogen, respectively). CMRO2 decreased for ‘CO2 in air’ (−13.4% ± 13.0%, p < 0.01) compared to room-air, while the CMRO2 during carbogen did not significantly change. Our findings indicate that ‘CO2 in air’ is not iso-metabolic, while carbogen appears to elicit a mixed effect; the CMRO2 reduction during hypercapnia is mitigated when including hyperoxia. These findings can be important for interpreting measurements using hypercapnic or hypercapnic-hyperoxic (carbogen) stimuli.

Non-Invasive Monitoring of Hemodynamic Parameters during Hemodialysis

1995 ◽  
Vol 18 (9) ◽  
pp. 499-503 ◽  
Author(s):  
F. Pizzarelli ◽  
P. Dattolo ◽  
M. Piacenti ◽  
M.A. Morales ◽  
T. Cerrai ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Blood Volume ◽  
Impedance Cardiography ◽  
Hemodynamic Parameters ◽  
Non Invasive ◽  
Transthoracic Impedance ◽  
Cardiac Output Index ◽  
On Line ◽  
Two Parameters

We studied in 13 hemodialysis patients intradialytic variations of blood volume (BV) and cardiac output, by means of non-invasive methods. We found a weak correlation, r 0.2 or less, between BV variations and intradialysis blood pressure variations. The sensitivity of the former in describing the variations of the latter was only 32%. During the 30 min preceeding the hypotensive crisis the percent BV variations did not show any predictive trend. On the contrary, refilling increased as blood pressure dropped and a weak inverse relation (r -0.35) was found between these two parameters. Unstable patients had predialytic blood volume values significantly lower than stable ones and comparable to healthy subjects. On the contrary, the correlation between percent variations of cardiac output index and MAP was 0.68 with a sensitivity and specificity of 90% and 59%, respectively. Unfortunately these promising results were obtained only with an estimate of cardiac output obtained by echocardiography and not by transthoracic impedance cardiography, which is much more feasible than the former as on-line monitoring of cardiac output. On-line monitoring of hemodynamic parameters is an appealing but still unsolved task.

Total cerebral blood volume calculated from a model of [99mTc]pertechnetate distribution in the head

1993 ◽  
Vol 74 (6) ◽  
pp. 2886-2895 ◽  
Author(s):  
A. Keyeux ◽  
D. Ochrymowicz-Bemelmans ◽  
C. Van Eyll ◽  
A. A. Charlier
Keyword(s):  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Bolus Injection ◽  
Compartment Model ◽  
Normal Density ◽  
Jugular Veins ◽  
Time Activity ◽  
99Mtc Pertechnetate ◽  
Activity Curve ◽  
Carotid And Vertebral Arteries

A method for calculation of the blood volume from the internal carotid and vertebral arteries to the internal jugular veins [total cerebral blood volume (TCBV)] was validated. This was achieved noninvasively in anesthetized rats from the time-activity curve recorded over the head after [99mTc]pertechnetate (Tc) intravenous bolus injection. Tc had the advantage over many other tracers in that it rapidly and evenly distributed in blood cells and plasma. Tc was found to behave in the head according to a two-parallel-compartment model containing a fast cerebral compartment and a slow extracerebral compartment. This model was mathematically described by a sum of two lagged normal density curves (LNDC) that fitted the head curve adequately. Responses of the LNDC parameters to flow and volume variations were first tested on a hydraulic setup. TCBV was calculated from the LNDC parameters of the cerebral fast compartment and the simultaneously determined cardiac output. In normocapnic rats, TCBV amounted to 49 +/- 7 (SD) microliters/g, distributed approximately two-thirds in the extra-parenchymal and one-third in the intraparenchymal cerebral vasculatures.

Sign in / Sign up

Export Citation Format

Share Document