scholarly journals A positron-probe system for arterial input function quantification for positron emission tomography in humans

2008 ◽  
Vol 79 (6) ◽  
pp. 064301 ◽  
Author(s):  
Kihak Lee ◽  
Peter T. Fox ◽  
Jack L. Lancaster ◽  
Paul A. Jerabek
Keyword(s):  
Positron Emission Tomography ◽  
Arterial Input Function ◽  
Input Function ◽  
Emission Tomography ◽  
Positron Emission ◽  
Probe System

scholarly journals In vivo Serotonin-Sensitive Binding of [11C]CUMI-101: A Serotonin 1A Receptor Agonist Positron Emission Tomography Radiotracer

2010 ◽  
Vol 31 (1) ◽  
pp. 243-249 ◽  
Author(s):  
Matthew S Milak ◽  
Alin J Severance ◽  
Jaya Prabhakaran ◽  
JS Dileep Kumar ◽  
Vattoly J Majo ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Arterial Input Function ◽  
Input Function ◽  
Emission Tomography ◽  
Binding Potential ◽  
Papio Anubis ◽  
Positron Emission ◽  
Future Work ◽  
G Protein Coupled

Positron emission tomography studies of 5-hydroxytryptamine (5-HT)1A receptors have hitherto been limited to antagonist radiotracers. Antagonists do not distinguish high/low-affinity conformations of G protein-coupled receptors and are less likely to be sensitive to intrasynaptic serotonin levels. We developed a novel 5-HT1A agonist radiotracer [11C]CUMI-101. This study evaluates the sensitivity of [11C]CUMI-101 binding to increases in intrasynaptic serotonin induced by intravenous citalopram and fenfluramine. Two Papio anubis were scanned, using [11C]CUMI-101 intravenous bolus of 4.5±1.5 mCi. Binding potential (BPF= Bavail/ KD) was measured before ( n=10) and 20 minutes after elevation of intrasynaptic serotonin by intravenous citalopram (2 mg/kg, n=3; 4 mg/kg, n=3) and fenfluramine (2.5 mg/kg, n=3) using a metabolite-corrected arterial input function. Occupancy was also estimated by the Lassen graphical approach. Both citalopram and fenfluramine effects were significant for BPF ( P=0.031, P=0.049, respectively). The Lassen approach estimated 15.0, 30.4, and 23.7% average occupancy after citalopram 2 mg/kg, 4 mg/kg, and fenfluramine 2.5 mg/kg, respectively. [11C]CUMI-101 binding is sensitive to a large increase in intrasynaptic serotonin in response to robust pharmacological challenges. These modest changes in BPF may make it unlikely that this ligand will detect changes in intrasynaptic 5-HT under physiologic conditions; future work will focus on evaluating its utility in measuring the responsiveness of the 5-HT system to pharmacological challenges.

Arterial input function sampling without surgery in rats for positron emission tomography molecular imaging

2014 ◽  
Vol 35 (6) ◽  
pp. 666-676 ◽  
Author(s):  
Etienne Croteau ◽  
Eric Poulin ◽  
Sébastien Tremblay ◽  
Véronique Dumulon-Perreault ◽  
Otman Sarrhini ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Molecular Imaging ◽  
Arterial Input Function ◽  
Input Function ◽  
Emission Tomography ◽  
Positron Emission

scholarly journals Noninvasive Estimation of the Arterial Input Function in Positron Emission Tomography Imaging of Cerebral Blood Flow

2012 ◽  
Vol 33 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Yi Su ◽  
Ana M Arbelaez ◽  
Tammie LS Benzinger ◽  
Abraham Z Snyder ◽  
Andrei G Vlassenko ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid ◽  
Arterial Input Function ◽  
Input Function ◽  
Emission Tomography ◽  
Positron Emission ◽  
Arterial Sampling

Positron emission tomography (PET) with 15O-labeled water can provide reliable measurement of cerebral blood flow (CBF). Quantification of CBF requires knowledge of the arterial input function (AIF), which is usually provided by arterial blood sampling. However, arterial sampling is invasive. Moreover, the blood generally is sampled at the wrist, which does not perfectly represent the AIF of the brain, because of the effects of delay and dispersion. We developed and validated a new noninvasive method to obtain the AIF directly by PET imaging of the internal carotid artery in a region of interest (ROI) defined by coregistered high-resolution magnetic resonance angiography. An ROI centered at the petrous portion of the internal carotid artery was defined, and the AIF was estimated simultaneously with whole brain blood flow. The image-derived AIF (IDAIF) method was validated against conventional arterial sampling. The IDAIF generated highly reproducible CBF estimations, generally in good agreement with the conventional technique.

scholarly journals Evaluation of Dopaminergic Presynaptic Integrity: 6-[18F]Fluoro-L-Dopa Versus 6-[18F]Fluoro-L-m-Tyrosine

1999 ◽  
Vol 19 (3) ◽  
pp. 278-287 ◽  
Author(s):  
D. J. Doudet ◽  
G. L.-Y. Chan ◽  
S. Jivan ◽  
O. T. DeJesus ◽  
E. G. McGeer ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Metabolic Pathway ◽  
Arterial Input Function ◽  
Occipital Cortex ◽  
Input Function ◽  
Emission Tomography ◽  
Dopa Decarboxylase ◽  
Positron Emission ◽  
Pet Scans

The effectiveness of 6-[18F]fluoro-L- m-tyrosine (6FMT) to evaluate dopamine presynaptic integrity was compared to that of 6-[18F]fluoro-L-dopa (6FDOPA) in vivo by positron emission tomography (PET). Six normal and six 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) -lesioned monkeys received 6FDOPA and 6FMT PET scans on separate occasions with identical scanning protocols. Four measures, the rate of uptake of tracer into striatum using either the arterial input function ( Ki) or the activity in the occipital cortex as the input function ( Kc), the rate of loss of striatal radioactivity ( kloss), and an index of “effective turnover” of dopamine ( kloss/ Ki), were obtained for both tracers during extended PET studies. 6-[18F]Fluoro-L- m-tyrosine was as effective as 6FDOPA in separating normals from MPTP-lesioned subjects on the basis of the uptake rate constants Ki and Kc. However, in contrast to 6FDOPA, it was not possible to differentiate the normal from the lesioned animal using kloss or kloss/ Ki for 6FMT. Thus, FMT appears to be a reasonable, highly specific tracer for studying the activity of aromatic dopa decarboxylase enzyme as an index of presynaptic integrity. However, if one is interested in investigating further the metabolic pathway and obtaining an in vivo estimate of the effective turnover of dopamine (after pharmacologic manipulation, for example), 6FDOPA remains the tracer of choice.

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