scholarly journals Comparison of Quantitative Autoradiographic and Xenon-133 Clearance Methods: Correlation of Gray and White Matter Cerebral Blood Flow with Compartmental Blood Flow Indices

1986 ◽  
Vol 6 (4) ◽  
pp. 481-485 ◽  
Author(s):  
U. I. Tuor ◽  
W. Fitch ◽  
D. I. Graham ◽  
A. D. Mendelow
Keyword(s):  
Blood Flow ◽  
White Matter ◽  
Gray Matter ◽  
Slow Flow ◽  
Stable Measure ◽  
Flow Component ◽  
Primate Brain ◽  
Xenon 133 ◽  
Fast Flow ◽  
Clearance Methods

The relationships between CBF in gray and white matter to those of the fast and slow components of xenon-133 clearance curves remain uncertain. CBF was measured in 13 anaesthetized baboons under a variety of conditions, using both the xenon-133 clearance technique and [14C]iodoantipyrine quantitative autoradiography. There was a linear relationship between CBF, as determined by the stochastic (height/area) analysis of the clearance curve, and mean CBF determined from the autoradiograms ( r = 0.94, p < 0.001, slope = 0.86 ± 0.09). There was also a linear correlation between the fast-flow component (measured with xenon-133) and blood flow in the cerebral gray matter (measured with [14C]iodoantipyrine) ( r = 0.92, p < 0.001, slope = 0.69 ± 0.15) and between the slow-flow component (with xenon-133) and blood flow in white matter (with [14C]iodoantipyrine) ( r = 0.79, p < 0.01, slope = 0.81 ± 0.10). In the primate brain, the fast- and slow-flow indices therefore appear to be representative of CBF in gray matter and white matter, respectively, whereas the stochastic analysis provides a stable measure of mean CBF within the tissue monitored.

Cerebral blood flow during cardiac operations: Comparison of Kety-Schmidt and xenon-133 clearance methods

1995 ◽  
Vol 59 (3) ◽  
pp. 614-620 ◽  
Author(s):  
David J. Cook ◽  
Robert E. Anderson ◽  
John D. Michenfelder ◽  
William C. Oliver ◽  
Thomas A. Orszulak ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Xenon 133 ◽  
Cardiac Operations ◽  
Clearance Methods

Accuracy of methods for calculating cerebral blood flow from intracarotid xenon-133 injection

1980 ◽  
Vol 238 (5) ◽  
pp. H750-H758
Author(s):  
J. P. Marc-Vergnes ◽  
P. Celsis ◽  
J. P. Charlet ◽  
G. Setien
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Gray Matter ◽  
Relative Weight ◽  
Compartmental Analysis ◽  
Optimization Method ◽  
Initial Slope ◽  
Method Of Calculation ◽  
Blood Flows ◽  
Xenon 133

The accuracy of the three commonly used methods, the initial slope analysis, the stochastic analysis, and the compartmental analysis, for calculating mean cerebral blood flow from xenon-133 clearance curves was studied with the use of computer-generated and real curves. The accuracy of calculation was affected by the cutoff time of the curve, by the level of the compartmental blood flows to white and gray matter and by the ratio of these flow levels, by the relative weight of gray matter, and by the choice of the method of calculation. None of the methods was clearly superior to the others. Each had its own defects that render it more or less suitable for different situations. All three methods generally overestimated mean cerebral blood flow. This overestimation was greater the lower the flow. A curve-fitting index was devised which can be used to check the validity of the bicompartmental model when using compartmental analysis. This same index can provide, though not always, an estimate of the error in the calculation of mean cerebral blood flow when an optimization method is used.

Characteristics of reactive hyperemia in the cerebral circulation

1984 ◽  
Vol 246 (1) ◽  
pp. H52-H58 ◽  
Author(s):  
J. K. Gourley ◽  
D. D. Heistad
Keyword(s):  
Blood Flow ◽  
White Matter ◽  
Cerebral Ischemia ◽  
Gray Matter ◽  
Cerebral Circulation ◽  
Time Course ◽  
Reactive Hyperemia ◽  
Arterial Occlusion ◽  
Maximal Peak ◽  
Minimal Resistance

Reactive hyperemia has been characterized in many vascular beds, but little is known about quantitative characteristics of reactive hyperemia in the cerebral circulation. We measured velocity of blood flow and pial artery diameter to characterize the time course of reactive hyperemia and used microspheres to study regional blood flow in the brain. Cerebral ischemia was produced by raising intracranial pressure or by arterial occlusion with a cuff around the neck. Five seconds of ischemia produced virtually maximal peak reactive hyperemia, and 30 s of ischemia produced maximal peak reactive hyperemia. During reactive hyperemia after 30 s of cerebral ischemia, there was a three- to fourfold increase in cerebral blood flow. The magnitude of reactive hyperemia was greater in gray matter than in white matter. Minimal resistance during reactive hyperemia, after ischemia produced by arterial occlusion, is similar to minimal resistance during seizures or hypercapnia, which suggests that reactive hyperemia produces maximal vasodilatation. Oxygen saturation of cerebral venous blood increased almost twofold during reactive hyperemia, which indicates that factors in addition to venous (and presumably tissue) oxygen are important determinants of reactive hyperemia. In summary, 1) we have characterized the time course of reactive hyperemia in the cerebral circulation; 2) reactive hyperemia after arterial occlusion produces maximal cerebral vasodilatation; and 3) there is marked heterogeneity of the response, with much larger increases in flow in cortical gray matter than white matter.

[14C]iodoantipyrine and microsphere blood flow estimates in cat brain

1987 ◽  
Vol 253 (5) ◽  
pp. H1289-H1297
Author(s):  
F. J. Schuier ◽  
S. C. Jones ◽  
T. Fedora ◽  
M. Reivich
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Spatial Resolution ◽  
Gray Matter ◽  
Local Cerebral Blood Flow ◽  
Normal Appearance ◽  
Diffusion Limited ◽  
Cat Brain ◽  
Temporal And Spatial

A comparison of local cerebral blood flow estimates with the microsphere and the 4-[N-methyl-14C]iodoantipyrine ([14C]IAP) techniques has been performed in cats. Good correlation of [14C]IAP with microsphere flow estimates in the gray matter was found. In the white matter, however, [14C]IAP flow estimates were consistently lower than microsphere flow estimates. Error analysis of both techniques and comparison with previous studies suggest that peculiarities of white matter arterial vasculature with preferential microsphere accumulation may lead to this discrepancy. Microspheres did not interfere with flow as shown by the normal appearance of subsequent [14C]IAP autoradiograms. The number of microspheres seen on autoradiograms was used for an estimate of microvessels blocked by spheres and found to be negligible. The study also demonstrates that [14C]IAP is not diffusion limited up to the observed flow values of 2 ml.g-1.min-1. Both techniques might be used together for a combination of their respective advantages, which are temporal and spatial resolution for microsphere and [14C]IAP, respectively.

Effect of aminophylline and isoproterenol on spinal cord blood flow after impact injury

1980 ◽  
Vol 53 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Diana Dow-Edwards ◽  
Vincent DeCrescito ◽  
John J. Tomasula ◽  
Eugene S. Flamm
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Adenosine Monophosphate ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury ◽  
Matter Flow

✓ A study of the effects of spinal cord injury upon spinal cord blood flow was carried out in cats. A 400 gm-cm impact produced an overall reduction in spinal cord blood flow of 24% in the white matter and 30% in the gray matter, as determined by 14C-antipyrine autoradiography. At the level of the injury, white-matter flow was 8.1 ml/100 gm/min, a reduction of 49%, and in the gray matter, 12.5 ml/100 gm/min, a reduction of 76%. Treatment with aminophylline and isoproterenol improved the overall blood flow in the spinal cord. At the level of the injury, white-matter flow after this treatment was no longer significantly different from control values. The gray-matter flow remained decreased to 26.2 ml/100 gm/min, a reduction of only 47%. It is proposed that aminophylline and isoproterenol may increase cyclic adenosine monophosphate (AMP) and prevent platelet aggregation along the endothelial surfaces of the microcirculation, and may thereby help to maintain improved perfusion of the injured spinal cord.

Effect of acute spinal cord compression injury on regional spinal cord blood flow in primates

1976 ◽  
Vol 45 (6) ◽  
pp. 660-676 ◽  
Author(s):  
Alan N. Sandler ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Regional Blood Flow ◽  
Compression Injury ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury

✓ Spinal cord blood flow (SCBF) was measured in 24 rhesus monkeys after injury to the cord produced by the inflatable circumferential extradural cuff technique. Measurement of regional blood flow in the white and gray matter of the cord in areas of 0.1 sq mm was achieved with the 14C-antipyrine autoradiographic technique and a scanning microscope photometer. After moderate cord injury (400 mm Hg pressure in the cuff maintained for 5 minutes), which produced paraplegia in 50% of animals and moderate to severe paresis in the other 50%, mean white matter SCBF was significantly decreased for up to 1 hour. White matter blood flow then rose to normal levels by 6 hours posttrauma and was significantly increased by 24 hours posttrauma. Gray matter SCBF was significantly decreased for the entire 24-hour period post-trauma. After severe cord injury (150 mm Hg pressure in the cuff maintained for 3 hours), which produced total paraplegia in almost all animals, SCBF in white and gray matter was reduced to extremely low levels for 24 hours posttrauma. In addition, focal decreases in SCBF were seen in white and gray matter for considerable distances proximal and distal to the injury site. It is concluded that acute compression injury of the spinal cord is associated with long-lasting ischemia in the cord that increases in severity with the degree of injury.

Studies of experimental cervical spinal cord transection

1979 ◽  
Vol 50 (5) ◽  
pp. 633-638 ◽  
Author(s):  
Phillip A. Tibbs ◽  
Byron Young ◽  
R. G. McAllister ◽  
Edward P. Todd
Keyword(s):  
Blood Flow ◽  
White Matter ◽  
Gray Matter ◽  
Injured Patient ◽  
Control Group ◽  
Content Type ◽  
Cervical Laminectomy ◽  
Cortical Gray Matter ◽  
Experimental Group ◽  
Fine Print

✓ Regional cerebral blood flow (CBF) was measured by the microsphere technique in anesthetized, mechanically ventilated dogs before and after cervical laminectomy in four (control group), or cervical laminectomy followed by cervical cord transection (CCT) at the C-6 level in six (experimental group). No significant differences in arterial pH, pO2 or pCO2 were observed between control and experimental dogs. Baseline values for mean arterial pressure (MAP) were also similar in the two groups, but MAP fell in all experimental dogs after CCT (p < 0.025). At 120 minutes after CCT, three of the six dogs had an MAP > 60 torr (66 ± 4 torr), and in three the MAP was < 50 torr (45 ± 3 torr). Regional CBF in cortical gray matter, white matter, and medulla did not change significantly after CCT in dogs with MAP > 60 torr. The CBF fell significantly at 120 minutes after CCT in all regions sampled in the dogs with MAP < 50 torr (p < 0.025). At 30 and 120 minutes after CCT, cerebellar blood flow fell significantly in all experimental animals (p < 0.05). These findings indicate that, despite hypotension and sympathetic denervation of cerebral vessels, CBF in cortical gray matter, white matter, and medulla is maintained at normal levels after CCT by autoregulation as long as MAP exceeds 60 torr. Decreased cerebellar blood flow in the experimental group suggests redistribution of CBF after CCT with relative preservation of flow to gray matter, white matter, and medulla. Reduced CBF in the acutely cord-injured patient with significant hypotension (MAP < 60 torr) may simulate or complicate coexistent head injury.

scholarly journals Noninvasive Method of Estimating Human Newborn Regional Cerebral Blood Flow

1982 ◽  
Vol 2 (4) ◽  
pp. 415-420 ◽  
Author(s):  
D. P. Younkin ◽  
M. Reivich ◽  
J. Jaggi ◽  
W. Obrist ◽  
M. Delivoria-Papadopoulos
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Gray Matter ◽  
Regional Cerebral Blood Flow ◽  
Relative Weight ◽  
Initial Slope ◽  
Noninvasive Method ◽  
Regional Cerebral Blood ◽  
Fractional Flow ◽  
Xenon 133

A noninvasive method of estimating regional cerebral blood flow (rCBF) in premature and full-term babies has been developed. Based on a modification of the xenon-133 inhalation rCBF technique, this method uses eight extracranial NaI scintillation detectors and an i. v. bolus injection of xenon-133 (∼0.5 mCi/kg). Arterial xenon concentration was estimated with an external chest detector. Cerebral blood flow was measured in 15 healthy, neurologically normal premature infants. Using Obrist's method of two-compartment analysis, normal values were calculated for flow in both compartments, relative weight and fractional flow in the first compartment (gray matter), initial slope of gray matter blood flow, mean cerebral blood flow, and initial slope index of mean cerebral blood flow. The application of this technique to newborns, its relative advantages, and its potential uses are discussed.

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