CBF and oxygen metabolism in hemodialysis patients: effects of anemia correction with recombinant human EPO

1992 ◽  
Vol 262 (5) ◽  
pp. F737-F743 ◽  
Author(s):  
H. Hirakata ◽  
H. Yao ◽  
S. Osato ◽  
S. Ibayashi ◽  
K. Onoyama ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Recombinant Human Erythropoietin ◽  
Oxygen Metabolism ◽  
Hemodialysis Patients ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Absolute Value ◽  
Human Erythropoietin ◽  
Positron Emission

To investigate the effects of anemia correction with recombinant human erythropoietin (rhEPO) on both cerebral blood flow and oxygen metabolism in hemodialysis (HD) patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF), and metabolic rate for oxygen (rCMRO2) were measured by positron emission tomography in five HD patients, and the data were compared with eight nondemented controls who had neither anemia nor uremia. In the HD patients, 1,500 U of rhEPO were administered intravenously three times a week to achieve a 10% increase in hematocrit (Hct) as an absolute value. Before rhEPO administration, the hemispheric rCMRO2 in HD patients was 1.48 +/- 0.09 (SE) ml.min-1.100 ml-1, which was significantly lower than that of 2.18 +/- 0.10 in the controls (P less than 0.01). In contrast, both rCBF and rOEF were significantly greater in the HD patients than the control, being 40 +/- 3 vs. 32 +/- 3 ml.min-1.100 ml-1 for rCBF (P less than 0.02) and 49 +/- 1 vs. 38 +/- 1% for rOEF (P less than 0.001). After treatment with rhEPO, Hct rose significantly from 21 +/- 1 to 31 +/- 1% in HD patients (P less than 0.001). There were significant reductions in both the hemispheric rCBF to 32 +/- 1 ml.min-1.100 ml-1 (P less than 0.01) and rOEF to 42 +/- 1% (P less than 0.01). However, the hemispheric rCMRO2 remained low at 1.58 +/- 0.06 ml.min-1.100 ml-1 even after rhEPO treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional Cerebral Blood Flow and Oxygen Metabolism during Migraine with and Without Aura

Cephalalgia ◽  
1997 ◽  
Vol 17 (5) ◽  
pp. 570-579 ◽  
Author(s):  
JLR Andersson ◽  
C Muhr ◽  
A Lilja ◽  
S Valind ◽  
PO Lundberg ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Oxygen Metabolism ◽  
Emission Tomography ◽  
Brain Atlas ◽  
Regional Cerebral Blood ◽  
Positron Emission ◽  
Exploratory Approach

Eleven cases of migraine with and without aura were investigated with positron emission tomography (PET). Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO2) and oxygen extraction (rOER) were measured during baseline ( n = 11), aura ( n = 6), headache ( n = 10) and after treatment with sumatriptan ( n = 4). Data were analysed using and ROI-based approach from 26 different anatomically defined regions, and also an exploratory approach whereby all subjects were normalized to a stereotactic brain atlas; t-maps were constructed by depicting significant changes between states. The exploratory approach revealed a region corresponding to the primary visual cortex with significant reductions in rCBF (23.1%) and rCMRO2 (22.5%), but no change in rOER during the headache phase compared to baseline. These data suggest that cerebral ischemia was not the primary cause of the attacks in these cases.

scholarly journals A Simplified in vivo Autoradiographic Strategy for the Determination of Regional Cerebral Blood Flow by Positron Emission Tomography: Theoretical Considerations and Validation Studies in the Rat

1982 ◽  
Vol 2 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Myron D. Ginsberg ◽  
Alan H. Lockwood ◽  
Raul Busto ◽  
Ronald D. Finn ◽  
Cathy M. Butler ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Animal Studies ◽  
Blood Flow Rate ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Positron Emission

A simplified mathematical model is described for the measurement of regional cerebral blood flow by positron emission tomography in man, based on a modification of the autoradiographic strategy originally developed for experimental animal studies. A modified ramp intravenous infusion of radiolabeled tracer is used; this results in a monotonically increasing curvilinear arterial activity curve that may be accurately described by a polynomial of low degree (= z). Integrated cranial activity C̄ B is measured in regions of interest during the latter portion of the tracer infusion period (times T1 to T2). It is shown that [Formula: see text] where each of the terms A x is a readily evaluated function of the blood flow rate constant k, the brain:blood partition coefficient for the tracer, the cranial activity integration limits T1 and T2, the coefficients of the polynomial describing the arterial curve, and an iteration factor n that is chosen to yield the desired degree of precision. This relationship permits generation of a table of C̄ B vs. k, thus facilitating on-line computer solution for blood flow. This in vivo autoradiographic paradigm was validated in a series of rats by comparing it to the classical autoradiographic strategy developed by Kety and associates. Excellent agreement was demonstrated between blood flow values obtained by the two methods: CBF in vivo = CBFclassical X 0.99 − 0.02 (units in ml g−1 min−1; correlation coefficient r = 0.966).

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