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.

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.

Compartmental abnormalities of regional cerebral blood flow in children with head trauma

1972 ◽  
Vol 36 (4) ◽  
pp. 463-470 ◽  
Author(s):  
Samuel S. Kasoff ◽  
Lawrence H. Zingesser ◽  
Kenneth Shulman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Gray Matter ◽  
Regional Cerebral Blood Flow ◽  
Head Injuries ◽  
Relative Weight ◽  
Compartmental Analysis ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Pediatric Age Group

✓ Regional cerebral blood flow (CBFr) and compartmental analysis in a series of children with closed head injuries have demonstrated abnormalities of both rate and distribution of blood flow. The most frequent derangement was a triphasic flow pattern overlying one or more regions of traumatized brain. The rate of flow in this third compartment is two to five times the rate of normal gray matter flow; while the relative weight of the compartment varies between 3.5% and 15%. The pathophysiology of this third, rapid compartment of flow is discussed, and the argument put forth that such flow does not represent hyperperfusion but rather an ischemia of the gray matter because such blood flow is not available to the tissue for nutrition. If this is so, it may well be a cause of permanent sequelae in the pediatric age group.

Evaluation of xenon-133 renal blood flow measurement in the intact rat

1983 ◽  
Vol 244 (5) ◽  
pp. F564-F573
Author(s):  
T. J. Butt ◽  
D. R. Jones ◽  
A. T. Wallis ◽  
F. O. Simpson
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Direct Measurement ◽  
Regression Line ◽  
Compartmental Analysis ◽  
Initial Slope ◽  
Blood Flows ◽  
Wide Range ◽  
Renal Flow ◽  
Xenon 133

The xenon-133 method for measuring renal blood flow in the intact rat was evaluated by direct measurement using a nonhemolyzing pump to perfuse kidneys in situ with the rat's own blood. Flows were calculated from the xenon data by means of four commonly used types of analysis: compartmental analysis using the weighted arithmetic mean (WAM), compartmental analysis using the weighted harmonic mean (WHM), stochastic analysis (SA), and initial slope analysis (ISA). WHM and SA estimate actual blood flows, whereas WAM and ISA provide only an index of mean renal flow. All results correlated well with the pumped flows (r values ranged from 0.79 to 0.98). However, the various types of analysis gave a wide range of calculated flows. This may explain some of the variation found in mean renal flow values reported in the literature. The method of choice was WHM, using only the first two compartments; the regression line between this (y) and direct measurement (x) was y = 0.98x + 0.17, r = 0.96.

scholarly journals Chroma-Memo-Flow Technique for Rapid Sequential Analysis of Regional Cerebral Blood Flow (rCBF) Responses

1978 ◽  
Vol 5 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Jørn Overgaard
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Sequential Analysis ◽  
Initial Slope ◽  
Functional Tests ◽  
Regional Cerebral Blood ◽  
Flow Calculation ◽  
Channel Memory ◽  
Xenon 133

SUMMARY:This is the first report of a method of sequential regional cerebral blood flow (rCBF) analysis, called Croma-Memo-Flow. This technique is a computerized modification of the initial slope method of regional cerebral blood flow (rCBF init.), allowing temporal resolution of the flow pattern by calculation of the slopes of sequential segments of the initial 1-2 minutes of the Xenon-133 washout curve. The same theoretical analysis applies to this method as to the rCBF init. method. Each flow calculation is based on the slope of a discrete 16 second segment of the initial washout; and each second the segment is advanced by one second. A new flow calculation is made each second and is displayed as a color coded map on a TV screen. Each map is labelled, indicating the time in seconds following Xenon injection, and sequential rCBF changes during the clearance period can be immediately visualized. This allows for almost instantaneous analysis and display of rapid or transient rCBF responses to activation and deactivation of the cerebral cortices.The data is stored in a 35 channel memory for deliberate replay, photography, and analysis.Functional tests may be applied during the initial washout period and both the magnitude and chronological relationships of the evoked regional cerebrovascular responses observed. A clinical study is presented to illustrate the possibilities of applying the technique to assess cortical reactivity.

Scattering of cerebral blood flow estimates using 133Xe intracarotid injection

1979 ◽  
Vol 236 (5) ◽  
pp. H680-H688
Author(s):  
P. Celsis ◽  
J. P. Marc-Vergnes ◽  
J. P. Charlet ◽  
A. Sevin
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Random Error ◽  
Stochastic Analysis ◽  
Relative Weight ◽  
Mean Flow ◽  
Empirical Formulas ◽  
Real Curves ◽  
Xenon 133 ◽  
Comparison Of The Results

Computer-generated and real curves were used to study the random error in the blood flow estimates calculated from xenon-133 cerebral clearance curves. The initial count rate affects the scattering under a threshold of 5,000 counts/s, but above this figure its influence is negligible. Flow values, relative weight of gray matter, and processes of analysis have also an effect. For the stochastic analysis, a theoretical standard deviation calculable from each experimental curve was proved. For other methods, empirical formulas were established. Using these formulas, intervals of uncertainty can be calculated allowing a useful comparison of the results obtained on the same patient, from different areas or from subsequent tests. Such intervals also allow the comparison of mean flow values obtained from a particular curve by the three usual processes of analysis. With high initial count rates, more than 75% of the intervals of uncertainty are disjointed. This suggests that the random error plays little part in the differences observed.

Vasospasm and Regional Cerebral Blood Flow (rCBF) in Patients with Ruptured Intracranial Aneurysm: Serial rCBF Studies with the Xenon-133 Inhalation Method

Neurosurgery ◽  
1983 ◽  
Vol 13 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Iwao Yamakami ◽  
Katsumi Isobe ◽  
Akira Yamaura ◽  
Takao Nakamura ◽  
Hiroyasu Makino
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Neurological Deficit ◽  
Mean Value ◽  
Initial Slope ◽  
Delayed Ischemic Neurological Deficit ◽  
Ruptured Intracranial Aneurysm ◽  
The Mean ◽  
Xenon 133 ◽  
Head Probe

Abstract To clarify the relationship of vasospasm to the reduction of cerebral blood flow (CBF) and the delayed ischemic neurological deficit, serial rCBF studies with the use of the xenon-133 inhalation method were conducted in 35 postoperative patients with ruptured intracranial aneurysms. The CBF was calculated as an initial slope index (ISI) derived from the desaturation curve of each head probe, and the hemispheric mean value of the ISI (mean ISI) was calculated in both hemispheres. The mean ISI in the hemisphere ipsilateral to the operation was low compared to that of the contralateral hemisphere. In relation to the presence of vasospasm, angiographic findings were classified into the following five types: diffuse, peripheral, proximal-severe, proximal-mild, and no spasm. Patients with vasospasm of the diffuse, peripheral, and proximal-severe types showed a markedly decreased mean ISI, and vasospasm of the diffuse type caused the greatest degree of reduction. The mean ISI of the patients who developed delayed ischemic neurological deficit (DIND) due to vasospasm was significantly decreased (37.4± 4.6) compared to that of the patients who did not develop DIND (52.2± 5.6). None of 3 cases of no spasm and only 1 of 14 cases of proximal-mild spasm developed DIND. On the other hand, all of 4 cases of diffuse, 2 of 3 cases of peripheral, and 2 of 6 cases of proximal-severe spasm developed DIND. Thus, if these three types of vasospasm are joined together as severe vasospasm, 8 of 13 cases with severe vasospasm developed DIND. These results suggest that severe vasospasm causes a reduction of CBF and that the reduced CBF brings about DIND.

Pentobarbital changes compartmental contribution to cerebral blood flow

1982 ◽  
Vol 56 (4) ◽  
pp. 504-510 ◽  
Author(s):  
John P. Laurent ◽  
Pablo Lawner ◽  
Frederick A. Simeone ◽  
Eugene Fink
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Intracranial Pressure ◽  
Content Type ◽  
Deep White Matter ◽  
Percentage Contribution ◽  
Blood Flows ◽  
Xenon 133 ◽  
Fine Print

✓ Barbiturates were administered to normal dogs, establishing an isoelectric electrocorticogram. Cortical cerebral blood flows (CBF) and deeper CBF's were respectively measured by krypton-85 (85Kr) and xenon-133 (133Xe). Following barbiturate administration, the two methods of measuring CBF showed a poor coefficient of variation (r = 0.12, p < 0.05). The cortical flows decreased less than the fast compartment flows. A shifting of percentage contribution of flow to the slow compartment (60% increase, p < 0.001) was observed after barbiturate infusion. A selective shunting of blood flow to the slower areas may explain the lowering of intracranial pressure and protection of the deep white matter observed by many authors who use barbiturates in clinical and experimental situations.

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

scholarly journals The Role of Electrode Size on the Incidence of Spreading Depression and on Cortical Cerebral Blood Flow as Measured by H2 Clearance

1992 ◽  
Vol 12 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Marleen J. Verhaegen ◽  
Michael M. Todd ◽  
David S. Warner ◽  
Bruce James ◽  
Julie B. Weeks
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Gray Matter ◽  
Spreading Depression ◽  
Insertion Depth ◽  
Flow Measurements ◽  
Electrode Size ◽  
Cortical Gray Matter ◽  
The Right

Cerebral blood flow was measured by the H2 clearance method 30 and 60 min after the implantation of 300, 250, 125, or 50 μm diameter platinum–iridium electrodes 2 mm deep into the right parietal cortex of normothermic, normocarbic halothane-anesthetized rats. Another group of animals had 50 μm electrodes inserted 1 mm. In all animals, the presence or absence of a wave of spreading depression (SD) was noted at the time of implantation, with recordings made with glass micropipettes. H2 flow values were compared with those measured in gray matter from the same anatomical region (but from different rats), using [3H]nicotine. The incidence of SD ranged from 60% following insertion of 300 μm electrodes to 0% with 50 μm electrodes. H2 clearance flows also varied with electrode size, from 77 ± 21 ml 100 g−1 min−1 (mean ± standard deviation) with 300 μm electrodes to 110 ± 31 and 111 ± 16 ml 100 g−1 min−1 with 125 and 50 μm electrodes, respectively (insertion depth of 2 mm). A CBF value of 155 ± 60 ml 100 g−1 min−1 was obtained with 50 μm electrodes inserted only 1 mm. Cortical gray matter blood flow measured with [3H]nicotine was 154 ± 35 ml 100 g−1 min−1. When the role of SD in subsequent flow measurements was examined, there was a gradual increase in CBF between 30 and 60 min after electrode insertion in those animals with SD, while no such change was seen in rats without SD. These results indicate that the choice of electrode size and implantation depth influences the measurement of CBF by H2 clearance. CBF values equivalent to those obtained with isotopic techniques can be acutely obtained with small (50 μm diameter) electrodes inserted 1 mm into the cortex. While the occurrence of SD does influence CBF in the period immediately after implantation, a relationship between electrode size and measured flow is present that is independent of SD.

scholarly journals Regional Cerebral Blood Flow during Rest and Skilled Hand Movements by Xenon-133 Inhalation and Emission Computerized Tomography

1981 ◽  
Vol 1 (4) ◽  
pp. 385-389 ◽  
Author(s):  
Martin Lauritzen ◽  
Leif Henriksen ◽  
Niels A. Lassen
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Single Photon ◽  
Photon Emission ◽  
Hand Movements ◽  
Regional Cerebral Blood ◽  
Symmetric Pattern ◽  
Xenon 133 ◽  
The Right

Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating (“dynamic”), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1-min period at a concentration of 10 mCi/L. The arrival and washout of the radioisotope was recorded during four 1-min periods. Two slices, 2 cm thick, 7 and 12 cm above the orbitomeatal line were obtained in every study. CBF averaged 60 ml/100 g/min (SD ± 11) in the lower slice and 51 ml/100 g/min (SD ± 13) in the upper slice. A symmetric pattern comparing right to left sides was found in both slices. Finger tapping and writing with the right hand increased CBF in specific areas of the upper slice: in the contralateral hand area by 35 ± 15% ( p < 0.025), and in the supplementary motor area on both sides by 34 ± 15% ( p < 0.025).

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