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 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).

Imaging Human Cerebral Pain Modulation by Dose-dependent Opioid Analgesia

2007 ◽  
Vol 106 (3) ◽  
pp. 548-556 ◽  
Author(s):  
Klaus J. Wagner ◽  
Till Sprenger ◽  
Eberhard F. Kochs ◽  
Thomas R. Tölle ◽  
Michael Valet ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Periaqueductal Gray ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Heat Stimulation ◽  
Positron Emission ◽  
Dose Dependent

Background Previous imaging studies have demonstrated a number of cortical and subcortical brain structures to be activated during noxious stimulation and infusion of narcotic analgesics. This study used O-water and positron emission tomography to investigate dose-dependent effects of the short-acting mu-selective opioid agonist remifentanil on regional cerebral blood flow during experimentally induced painful heat stimulation in healthy male volunteers. Methods Positron emission tomography measurements were performed with injection of 7 mCi O-water during nonpainful heat and painful heat stimulation of the volar forearm. Three experimental conditions were used during both sensory stimuli: saline, 0.05 microg x kg x min remifentanil, and 0.15 microg x kg x min remifentanil. Cardiovascular and respiratory parameters were monitored noninvasively. Across the three conditions, dose-dependent effects of remifentanil on regional cerebral blood flow were analyzed on a pixel-wise basis using a statistical parametric mapping approach. Results During saline infusion, regional cerebral blood flow increased in response to noxious thermal stimulation in a number of brain regions as previously reported. There was a reduction in pain-related activations with increasing doses of remifentanil in the thalamus, insula, and anterior and posterior cingulate cortex. Increasing activation occurred in the cingulofrontal cortex (including the perigenual anterior cingulate cortex) and the periaqueductal gray. Conclusions Remifentanil induced regional cerebral blood flow increases in the cingulofrontal cortex and periaqueductal gray during pain stimulation, indicating that mu-opioidergic activation modulates activity in pain inhibitory circuitries. This provides direct evidence that opioidergic analgesia is mediated by activation of established descending antinociceptive pathways.

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%.

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