scholarly journals A new noninvasive quantification of renal blood flow with N-13 ammonia, dynamic positron emission tomography, and a two-compartment model.

1992 ◽  
Vol 3 (6) ◽  
pp. 1295-1306
Author(s):  
B C Chen ◽  
G Germano ◽  
S C Huang ◽  
R A Hawkins ◽  
H W Hansen ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Pet Imaging ◽  
Renal Cortex ◽  
Compartment Model ◽  
Regions Of Interest ◽  
Emission Tomography ◽  
Dynamic Positron Emission Tomography ◽  
Positron Emission ◽  
Two Compartment Model

In order to determine if dynamic positron emission tomography (PET) and N-13 ammonia can be used to quantitate regional RBF (rRBF) noninvasively, six anesthetized dogs were examined with PET imaging after an iv bolus administration of 5 mCi of N-13 ammonia. Renal time activity curves and the arterial input function were derived from regions of interest drawn over the renal cortex and abdominal aorta, respectively. For calculation of rRBF, less than 120 s of the initial data were used to minimize contamination by plasma metabolites of N-13 radioactivity. rRBF was quantitated with a two-compartment model, and the results were compared with simultaneously acquired microsphere blood flow measurement. Fourteen experiments were performed in six dogs, and four regions of interest on renal cortex were selected on each PET image. RBF derived from dynamic PET imaging with N-13 ammonia was linearly related to microsphere (MS) values (rRBF = 1.06 x MS - 0.17; r = 0.91). Mean rRBF in the canine experiments was 4.0 mL/min/g. The results indicate that dynamic N-13 ammonia renal PET can provide noninvasively quantitative rRBF.

Positron Emission Tomography

2014 ◽  
Author(s):  
Shalini Narayana ◽  
Babak Saboury ◽  
Andrew B. Newberg ◽  
Andrew C. Papanicolaou ◽  
Abass Alavi
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Pet Imaging ◽  
Molecular Probes ◽  
Emission Tomography ◽  
Metabolic Imaging ◽  
Imaging Method ◽  
Brain Physiology ◽  
Positron Emission ◽  
Clinical Scenarios

Positron emission tomography (PET) is an imaging method that utilizes compounds labeled with positron-emitting radioisotopes as molecular probes to evaluate different neurophysiological processes quantitatively and noninvasively. This chapter provides a background regarding positron emission, radiotracer chemistry, and detector and scanner instrumentation, as well as analytical methods for evaluating basic brain physiology, such as cerebral blood flow and oxygen and glucose metabolism. The methodological aspects of PET imaging, such as patient preparation and optimal scanning parameters, are discussed. Examples of application of blood flow and metabolic imaging in both research and clinical scenarios for the evaluation of normal neurophysiology are provided. Recent advances in PET imaging, including PET-CT and PET-MRI, are also described. Finally, the unique strengths of PET imaging are highlighted.

scholarly journals A Determination of the Regional Brain/Blood Partition Coefficient of Water Using Dynamic Positron Emission Tomography

1989 ◽  
Vol 9 (6) ◽  
pp. 874-885 ◽  
Author(s):  
Hidehiro Iida ◽  
Iwao Kanno ◽  
Shuichi Miura ◽  
Matsutaro Murakami ◽  
Kazuhiro Takahashi ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Partition Coefficient ◽  
Insular Cortex ◽  
Compartment Model ◽  
The Other ◽  
Emission Tomography ◽  
Dynamic Positron Emission Tomography ◽  
Single Compartment ◽  
Content Ratio ◽  
Positron Emission

In order to investigate the validity of the single compartment model in measuring CBF with the use of 15O-labeled water (H215O), dynamic positron emission tomography (PET) was performed following bolus injection of H215O. Careful attention was paid to accuracy in the measurement system (especially for the input function). In the region of the putamen, which includes the smallest mixture of gray and white matters in addition to the smallest contamination of cerebrospinal fluid (CSF) spaces, the partition coefficient obtained was 0.88 ± 0.06 (ml/g). The discrepancy from the prediction estimated from the brain/blood water content ratio was only 7%. This finding suggests that there is no more complicated model than the usual single compartment one to describe the physiological behaviour of 15O water. On the other hand, in the other cortical regions, the discrepancy was larger (e.g., about 12% for the insular cortex and 26% for the frontal cortex) than in the region of the putamen, and a significant fit–interval dependence was observed in the calculated parameters. These observations suggest a significant effect of tissue heterogeneity and/or contamination with nonperfusable spaces in actual clinical PET data.

scholarly journals Model Dependency and Estimation Reliability in Measurement of Cerebral Oxygen Utilization Rate with Oxygen-15 and Dynamic Positron Emission Tomography

1986 ◽  
Vol 6 (1) ◽  
pp. 105-119 ◽  
Author(s):  
Sung-Cheng Huang ◽  
DaGan Feng ◽  
Michael E. Phelps
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Low Noise ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Vascular Volume ◽  
Dynamic Positron Emission Tomography ◽  
Extraction Fraction ◽  
Positron Emission ◽  
Model Configuration

The use of oxygen-15 and dynamic positron emission tomography (PET) for the measurement of CMRO was investigated in terms of the achievable accuracy of CMRO and its sensitivity to model configuration assumed in the estimation. Three models of different descriptions for the vascular radioactivity in tissue were examined by computer simulation. By simulating the tracer kinetics with one model and curve fitting them with another, it was found that the CMRO measurement was very sensitive to the model configuration used and it needed kinetic data of low noise level to determine the correct model to use. The approach of sensitivity functions and covariance matrices was used to examine the estimation reliability and error propagation of the model parameters. It was found that for all three model configurations examined the reliability of the CMRO estimate was dependent on the blood flow and oxygen extraction fraction in tissue (∼2% in tissues of high blood flow and normal extraction and 10% in tissues of low blood flow and low extraction fraction, in a study of 1 × 106 counts/brain slice in 3 min). The estimation reliability is drastically decreased if the total data collection time is reduced to 1 min but is not critically sensitive to the scan sampling interval used. Estimating blood flow or vascular volume simultaneously with CMRO will reduce the reliability of the CMRO estimate by ∼50%. Propagation of parameter error from blood flow or vascular volume to CMRO is dependent on the model configuration as well as the scanning schedule and estimation procedure used. Results from the study provide useful information for improving the study procedure of CMRO measurements. The present study also illustrates a general representation of PET measurements and an approach that can be applied to other tracer techniques in PET for selecting appropriate model configurations and for designing proper experimental procedures.

scholarly journals Models for in vivo Kinetic Interactions of Dopamine D2-Neuroreceptors and 3-(2'-[18F]Fluoroethyl)Spiperone Examined with Positron Emission Tomography

1989 ◽  
Vol 9 (6) ◽  
pp. 840-849 ◽  
Author(s):  
Mark M. Bahn ◽  
Sung-Cheng Huang ◽  
Randall A. Hawkins ◽  
Nagichettiar Satyamurthy ◽  
John M. Hoffman ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Nonlinear Model ◽  
Compartment Model ◽  
Emission Tomography ◽  
Positron Emission ◽  
Two Compartment Model ◽  
Model Configuration ◽  
Net Uptake ◽  
Kinetics Of

The in vivo tracer kinetics of 3-(2apos;-[18F]fluoroethyl)spiperone (FESP) in the caudate/striatum and cerebellar regions of the human and monkey brain were studied with positron emission tomography (PET). The minimal model configuration that can describe the kinetics was determined statistically. Three two-compartment model configurations were found to be suitable for describing the kinetics in caudate/striatum and cerebellum: (1) a nonlinear model (five parameters) applicable to studies using nontracer (partially saturating) quantities of FESP in monkey striatum, (2) a linear four-parameter model applicable to the caudate/striatal and cerebellar kinetics in human and monkey studies with tracer quantities of FESP, and (3) a linear three-parameter model derived from the four-parameter model by assuming irreversible binding applicable to tracer studies of the human caudate. In the human studies, when the caudate kinetics ( n = 4) were fit by model 2 (with four parameters), the value of the in vivo ligand dissociation constant kd was found to be 0.0015 ± 0.0032/min. The three-parameter model (model 3) was found to fit the data equally well; this model is equivalent to model 2 with kd set to zero. In the monkey studies, it was found that for short (90 min) studies using tracer quantities of FESP, model 2 fit the striatal kinetics better than model 3. The parameters estimated using model 2 (four parameters) were in better agreement with those estimated by the nonlinear model (model 1) than those estimated using model 3 (three parameters). The use of a graphical approach gives estimates of the plasma–tissue fractional transport rate constant K1 and the net uptake constant K3 comparable to estimates using model 3 for both human and monkey studies.

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