The Second Generation HRRT - a Multi Centre Scanner Performance Investigation

Jong, Hugo W. A. M. de; Barker, William; Bloomfield, Peter; Burbar, Z.; Camborde, M.-L.; Comtat, Claude; Eriksson, Lars; Houle, Sylvain; Keator, David B.; Knob, C.; Krais, R.; Lammertsma, Adriaan A.; Rahmim, Arman; Sibomana, M.; Teräs, Mika; Thompson, C.J.; Trébossen, R.; Votaw, John R.; Walker, Matthew; Wienhard, K.; Wong, Dean F.

doi:10.1109/nssmic.2005.1596770

Cited by 90 publications

(76 citation statements)

References 6 publications

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“…PET studies were performed on a High-Resolution Research Tomograph (CPS Innovations, Inc.), with a spatial resolution of 2.5 mm in full width at half maximum (21). The subjects had a venous catheter for the radioligand injection and an arterial catheter to obtain arterial blood samples for the determination of radioactivity in plasma.…”

Section: Human Brain Studymentioning

confidence: 99%

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PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with ¹⁸F-AZAN, a Radioligand with Optimal Brain Kinetics

et al. 2013

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We evaluated (2)-2-(6-[ 18 F]fluoro-2,39-bipyridin-59-yl)-7-methyl-7-aza-bicyclo[2.2.1]heptane ( 18 F-AZAN), a novel radiotracer that binds to a4b2 nicotinic acetylcholine receptors (a4b2-nAChRs) and shows high specific binding and rapid and reversible kinetics in the baboon and human brain. Methods: We tested safety tolerability and test-retest reliability (n 5 5) and proposed initial quantification of 18 F-AZAN receptors in 3 healthy human subjects who had nicotine exposure and 9 who did not. We also present a receptor blocking study in a nicotine subject dosed with the a4b2-nAChRselective partial agonist varenicline. Results: Radiation dosimetry PET/CT experiments indicated that most human organs received doses between 0.008 and 0.015 mSv/MBq, with an effective dose of approximately 0.014 mSv/MBq. The tracer rapidly entered the brain, and the peak was reached before 20 min, even for thalamus. Ninety-minute scans were sufficient for 18 F-AZAN to obtain the ratio at equilibrium of specifically bound radioligand to nondisplaceable radioligand in tissue (BP ND ) using plasma reference graphical analysis, which showed excellent reproducibility of BP ND (test-retest variability , 10%) in the nAChR-rich brain regions. Regional plasma reference graphical analysis BP ND values exceeded 2 in the midbrain tegmental nuclei, lateral geniculate body, and thalamus for nonsmokers (n 5 9) but were less than 1 in the nAChR-poor brain regions. There was a dramatic reduction of 18 F-AZAN brain uptake in smokers and varenicline-treated subjects. Conclusion: 18 F-AZAN is a highly specific, safe, and effective PET radioligand for human subjects that requires only 90 min of PET scanning to estimate high-affinity a4b2-nAChR in the living human brain.

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Section: Human Brain Studymentioning

confidence: 99%

“…The schedule was four 15-s, four 30-s, three 1-min, two 2-min, five 4-min, and twelve 5-min frames. The final spatial resolution is expected to be less than 2.5 mm in full width at half maximum in 3 directions (21).…”

Section: Human Brain Studymentioning

confidence: 99%

PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with ¹⁸F-AZAN, a Radioligand with Optimal Brain Kinetics

et al. 2013

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“…Because PET with 11 C requires an adjacent cylclotron due to the short (approximately 20 minutes) half-life of 11 C, [ 11 C]neuroreceptor PET imaging studies are restricted to PET centers equipped with a cyclotron and specially trained radiochemists. Figure 1 illustrates a state-of-the-art tomography instrument to provide high resolution images of the brain for research purposes [8] . Brain imaging techniques exist to demonstrate a vast array of receptors in the brain, including dopamine, serotonin, and acetylcholine.…”

Section: Introductionmentioning

confidence: 99%

“…In other words, contemporary imaging tools provide incomplete data to estimate neuroreceptors in the living human brain. The instrument produces images with a resolution approaching 2 mm [8] . Since there exist several subtypes of neurotransmitter receptors, there are often unique radiotracers to bind to specific subtypes of neurotransmitter receptors.…”

Section: Introductionmentioning

confidence: 99%

Neurotransmitter visualization in schizophrenia

Brašić

2013

JBGC

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Background: Although the history, interview, and examination of the patient provide the foundation for the diagnosis of schizophrenia, nuclear neuroimaging investigations constitute promising tools to elucidate the pathophysiology of schizophrenia and other neuropsychiatric disorders. Imaging studies of neuroreceptors constitute research tools to investigate the role of dysfunction of the acetylcholinergic, dopaminergic, glutamatergic, serotonergic, cannabinoid, opioid, and nicotinic systems in the pathogenesis and pathophysiology of schizophrenia and related conditions.People with the phenotype of the clinical syndrome of schizophrenia likely represent multiple distinct genotypes with poorly characterized biological traits. Thus, the population of people manifesting the clinical syndrome of schizophrenia likely contains several heterogeneous biological subgroups yet to be specified.The dopamine hypothesis of schizophrenia proposes that the positive symptoms result from an excess of intrasynaptic dopamine, an excitatory neurotransmitter, and the negative symptoms result from a deficit of intrasynaptic dopamine. Accordingly, a group of people with schizophrenia likely have reduced intrasynaptic dopamine in the tonic, resting, basal state, and increased intrasynaptic dopamine in the excited, aroused, phasic state.Additionally, the glutamate hypothesis of schizophrenia suggests that dysfunction of glutamate, another excitatory neurotransmitter, in the prefrontal region results in excessive concentrations of dopamine in the striata resulting in the positive symptoms of schizophrenia. Methodology/Principal Findings:Published research about the nuclear neuroimaging techniques to identify neurotransmitters in people with schizophrenia are reviewed.Conclusions/Significance: Future research including neuronuclear imaging and genetic evaluations is needed to characterize the biological subgroups of people with the clinical syndrome of schizophrenia. Neuronuclear imaging studies will likely refine the measurement of neurotransmitters in the presynaptic, synaptic, and postsynaptic regions in people with schizophrenia and healthy people. Imaging studies of neuroreceptors during the administration of putative therapeutic agents for schizophrenia will help determine the optimal dose. In the future the research findings summarized in this article will likely be translated into clinical practice.

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“…However, with the advent of the secondgeneration HRRT system ([high-resolution research tomograph] Siemens Medical Solutions, Inc.), the acuity of PET is beginning to match the source of its main focus of interest-the human cortex. In a recent study across multiple sites of installation, the resolution of this system has been demonstrated to provide near-isotropic spatial resolution of 2.5 mm in a volume containing a human brain (8). If the power of this new positron-emission tomograph is to be harnessed, new strategies for spatial normalization need to be used, such that the registration process does not dilute the observed signal further by introducing portions of white matter or cerebrospinal fluid compartments into the measurement volume.…”

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confidence: 99%

Cortical Flattening Applied to High-Resolution ¹⁸F-FDG PET

Klein¹,

Herholz²,

Wienhard³

et al. 2007

J Nucl Med

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Group studies using PET and other types of neuroimaging require some means to achieve congruence of brain structures across subjects, such that scans from individuals varying in brain shape and gyral anatomy can be analyzed together. Volume registration methods are the most widely used approach to achieve this congruence. They are fast and typically require little manual interaction, but, unfortunately, it is difficult to achieve a good match between cortical areas in volume space, especially where folding patterns vary across subjects. Cortical flattening is a recent, alternative strategy: Its key features are explicit definition of cortex, such that white matter or cerebrospinal fluid compartments are largely excluded from the analysis volume, and subsequent registration of the cortical sheet in its natural, 2-dimensional topology. This type of registration has been demonstrated to provide better matching of congruent cortical structures than volume methods and, thus, offers a potentially more robust way of analyzing PET data. Methods: Here, we explore the applicability of cortical flattening of coregistered MRI to 18 F-FDG PET on the HRRT system (high-resolution research tomograph), the highest-resolution whole-head scanner available to date. Results: We report average values and SD of cortical metabolism in a pilot study of the dominant hemisphere in 9 control subjects and provide estimates of group sizes necessary for studies using this technique. Conclusion: We conclude that cortical flattening with subsequent surface registration is a feasible and promising strategy for group studies on the HRRT, providing the highest fidelity maps of human cortical glucose consumption to date.

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The Second Generation HRRT - a Multi Centre Scanner Performance Investigation

Cited by 90 publications

References 6 publications

PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with ¹⁸F-AZAN, a Radioligand with Optimal Brain Kinetics

PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with ¹⁸F-AZAN, a Radioligand with Optimal Brain Kinetics

Neurotransmitter visualization in schizophrenia

Cortical Flattening Applied to High-Resolution ¹⁸F-FDG PET

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The Second Generation HRRT - a Multi Centre Scanner Performance Investigation

Cited by 90 publications

References 6 publications

PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with 18F-AZAN, a Radioligand with Optimal Brain Kinetics

PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with 18F-AZAN, a Radioligand with Optimal Brain Kinetics

Neurotransmitter visualization in schizophrenia

Cortical Flattening Applied to High-Resolution 18F-FDG PET

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PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with ¹⁸F-AZAN, a Radioligand with Optimal Brain Kinetics

PET Imaging of High-Affinity α4β2 Nicotinic Acetylcholine Receptors in Humans with ¹⁸F-AZAN, a Radioligand with Optimal Brain Kinetics

Cortical Flattening Applied to High-Resolution ¹⁸F-FDG PET