scholarly journals Tracer Disposition Kinetics in the Determination of Local Cerebral Blood Flow by a Venous Equilibrium Model, Tube Model, and Distributed Model

1987 ◽  
Vol 7 (4) ◽  
pp. 433-442 ◽  
Author(s):  
Y. Sawada ◽  
Y. Sugiyama ◽  
T. Iga ◽  
M. Hanano
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Equilibrium Model ◽  
Blood Concentration ◽  
Tissue Concentration ◽  
Distributed Model ◽  
Tube Model ◽  
Local Cerebral Blood Flow ◽  
Capillary Tube Model

Tracer distribution kinetics in the determination of local cerebral blood flow (LCBF) were examined by using three models, i.e., venous equilibrium, tube, and distributed models. The technique most commonly used for measuring LCBF is the tissue uptake method, which was first developed and applied by Kety (1951). The measurement of LCBF with the 14C-iodoantipyrine (IAP) method is calculated by using an equation derived by Kety based on the Fick's principle and a two-compartment model of blood–tissue exchange and tissue concentration at a single data point (Sakurada et al., 1978). The procedure, in which the tissue is to be in equilibrium with venous will be referred to as the tissue equilibration model. In this article, effects of the concentration gradient of tracer along the length of the capillary (tube model) and the transverse heterogeneity in the capillary transit time (distributed model) on the determination of LCBF were theoretically for the tissue sapling method. Similarities and differences among these models are explored. The rank order of the LCBF calculated by using arterial blood concentration time courses and the tissue concentration of tracer based on each model were tube model (model II) < distributed model (model III) < venous equilibrium model (model I). Data on 14C-IAP kinetics reported by Ohno et al. (1979) were employed. The LCBFs calculated based on model I were 45–260% larger than those in models II or III. To discriminate among three models, we propose to examine the effect of altering the venous infusion time of tracer on the apparent tissue-to-blood concentration ratio (Λapp). A range of the ratio of the predicted Λapp in models II or III to that in model I was from 0.6 to 1.3. In the future, there may be a need to determine which model should be used to calculate the LCBF based on this discriminator and to develop another discriminator by using multiple data points based on positron emission tomography.

scholarly journals Evaluation of [123I]Isopropyliodoamphetamine as a Tracer for Local Cerebral Blood Flow Using Direct Autoradiographic Comparison

1982 ◽  
Vol 2 (2) ◽  
pp. 179-185 ◽  
Author(s):  
James L. Lear ◽  
Robert F. Ackermann ◽  
Motonobu Kameyama ◽  
David E. Kuhl
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Partition Coefficient ◽  
Brain Uptake ◽  
Local Cerebral Blood Flow ◽  
Mean Values ◽  
Brain Uptake Index ◽  
First Pass ◽  
Potential Use

We investigated [123I]isopropyliodoamphetamine (IMP) for potential use in the autoradiographic determination of local cerebral blood flow (LCBF) in animals. The technique of direct autoradiographic comparison, derived from double radionuclide autoradiography, was used to compare the simultaneous uptakes of IMP and [14C]iodoantipyrine (IAP), a reference tracer, in awake and anesthetized rats. This new technique offers several advantages over the previously developed methods of comparing tracers, brain uptake index and first pass extraction ratio. These include the avoidance of disrupting normal cerebral blood–brain tracer exchange and the ability to compare uptakes at substructural levels, whereas the other methods are limited to larger areas. Mean values of LCBF obtained with IMP agreed closely with those using IAP, from 20 to 300 ml/100 g/min. Because IMP was found to have an extremely high effective brain:blood partition coefficient, approximately 25:1, a linear uptake tracer model could be used for IMP yielding more precise values than could IAP for LCBF values above 150. IMP was found to measure choroid plexus flows much more accurately than IAP, values being greater than 500 for IMP compared to approximately 200 for IAP. Because the mechanism of the extremely high partition coefficient of IMP is not yet defined, however, care must be used in measuring LCBF with IMP where the trapping mechanisms of normal vessels may be disrupted.

scholarly journals Measurement of Local Cerebral Blood Flow with [14C]Iodoantipyrine in the Mouse

1988 ◽  
Vol 8 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Therese M. Jay ◽  
Giovanni Lucignani ◽  
Alison M. Crane ◽  
Jane Jehle ◽  
Louis Sokoloff
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Time Course ◽  
Local Cerebral Blood Flow ◽  
Sources Of Error ◽  
Arterial Blood ◽  
Appropriate Care ◽  
Rapid Removal ◽  
The Brain

Local cerebral blood flow was measured in the mouse by means of the [14C]iodoantipyrine method. This method has been previously used in the monkey, dog, cat, and rat, but its application to small mammals such as the mouse requires special attention to potential sources of error. The small size of the mouse brain requires special attention to the rapid removal and freezing of the brain to minimize effects of postmortem diffusion of tracer in the tissue. Because of the relatively low diameter/length ratios of the catheters needed for arterial sampling in small animals, substantial errors can occur in the determination of the time course of the [14C]iodoantipyrine concentration in the arterial blood unless corrections for lag time and dead space washout in the catheter are properly applied. Local cerebral blood flow was measured in seven awake mice with appropriate care to minimize these sources of error. The values were found to vary from 48 ml/100 g/min in the corpus callosum to 198 ml/100 g/min in the inferior colliculus. The results demonstrate that the [14C]iodoantipyrine method can be used to measure local cerebral blood flow in the mouse and that the values in that species are, in general, somewhat higher than those in the rat.

scholarly journals Iodoamphetamine as a New Tracer for Local Cerebral Blood Flow in the Rat: Comparison with Isopropyliodoamphetamine

1984 ◽  
Vol 4 (2) ◽  
pp. 270-274 ◽  
Author(s):  
Jean R. Rapin ◽  
Monique Le Poncin-Lafitte ◽  
Dominique Duterte ◽  
Richard Rips ◽  
Elisabeth Morier ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Tissue Distribution ◽  
Brain Uptake ◽  
Local Cerebral Blood Flow ◽  
Brain Uptake Index ◽  
Derivatives Of ◽  
The Brain

Rats were injected with iodoamphetamine synthesized and labeled with 125I or with 125I-isopropyliodoamphetamine, a molecule of established value for the determination of local cerebral blood flow. The blood kinetics, tissue distribution, and brain uptake index for each tracer exhibited practically no differences. Autoradiographic quantification of the local cerebral blood flow, calculated according to the microsphere model, produced identical results for both molecules. However, compared with the values reported for other tracers, our values constituted an underestimation of white matter blood flow and a more real estimation of hippocampal flow. It is concluded from the brain uptake of the derivatives of both amphetamines during the first minutes following their injection that these tracers can be used as a chemical microembolus for the measurement of local cerebral blood flow.

Local cerebral PO2, PCO2, and blood flow measurements by mass spectrometry

1983 ◽  
Vol 245 (3) ◽  
pp. H513-H518
Author(s):  
J. Seylaz ◽  
E. Pinard ◽  
P. Meric ◽  
J. L. Correze
Keyword(s):  
Mass Spectrometry ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Tracer Gas ◽  
Local Cerebral Blood Flow ◽  
Flow Measurements ◽  
Partial Pressures ◽  
Short Period ◽  
Blood Flow Measurements

Partial pressures of intracerebral tissue gases (PO2, PCO2) and local cerebral blood flow (local CBF) were determined simultaneously by means of a single cannula implanted stereotaxically in a given structure. Minute quantities of the gases (O2, CO2, and tracer gas) were withdrawn continuously. After a short period of tracer (He) inhalation, CBF was measured by determination of the clearance rate (T1/2). The measurements of PO2 and PCO2 were continuous and quantitative, whereas the measurements of local CBF were sequential and quantitative. The results obtained for local CBF were compared with those found with two other methods (H2 clearance by polarography, thermoclearance) in the same structure of the same animal.

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