An inverse method for tracer kinetic modelling with positron emission tomography (PET) using hybrid method

2016 ◽  
Author(s):  
N. Kokulan ◽  
Y. Hai ◽  
E. George ◽  
C. H. Lai ◽  
L. Liu
Keyword(s):  
Positron Emission Tomography ◽  
Hybrid Method ◽  
Inverse Method ◽  
Kinetic Modelling ◽  
Emission Tomography ◽  
Tracer Kinetic Modelling ◽  
Positron Emission ◽  
Tracer Kinetic

A hybrid method of attenuation correction for positron emission tomography brain studies

1994 ◽  
Vol 21 (12) ◽  
pp. 1279-1284 ◽  
Author(s):  
Valentino Bettinardi ◽  
Maria Carla Gilardi ◽  
Serena Cargnel ◽  
Giovanna Rizzo ◽  
Mika Teräs ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Attenuation Correction ◽  
Hybrid Method ◽  
Emission Tomography ◽  
Positron Emission

scholarly journals Evaluation of [13N]ammonia positron emission tomography as a potential method for quantifying glutamine synthetase activity in the human brain.

2020 ◽  
Author(s):  
Alice Egerton ◽  
Joel Dunn ◽  
Nisha Singh ◽  
Zilin Yu ◽  
Jim O'Doherty ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Glutamine Synthetase ◽  
Human Brain ◽  
Kinetic Modelling ◽  
Emission Tomography ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Kinetic Rate Constant ◽  
Arterial Blood ◽  
Positron Emission

Abstract Purpose: The conversion of synaptic glutamate to glutamine in astrocytes by glutamine synthetase (GS) is critical to maintaining healthy brain activity and may be disrupted in several brain disorders. As the GS catalysed conversion of glutamate to glutamine requires ammonia, we evaluated whether [13N]ammonia positron emission tomography (PET) could reliability quantify GS activity in humans.Methods: In this test-retest study, eight healthy volunteers each received two dynamic [13N]ammonia PET scans on the morning and afternoon of the same day. Each [13N]ammonia scan was preceded by a [15O]water PET scan to account for effects of cerebral blood flow (CBF).Results: Concentrations of radioactive metabolites in arterial blood were available for both sessions in five of the eight subjects. Our results demonstrated that kinetic modelling was unable to reliably distinguish estimates of the kinetic rate constant k3 (related to GS activity) from K1 (related to [13N]ammonia brain uptake), and indicated a non-negligible back-flux of [13N] to blood (k2). Model selection favoured a reversible one-tissue compartmental model, and [13N]ammonia K1 correlated reliably (r2 = 0.72 - 0.92) with [15O]water CBF.Conclusion: The [13N]ammonia PET method was unable to reliably estimate GS activity in the human brain but may provide an alternative index of CBF.

scholarly journals ​Quantitative Evaluation of Hepatic Integrin Αvβ3 Expression by Positron-emission Tomography Imaging Using 18F-FPP-RGD2 in Rats With Non-alcoholic Steatohepatitis

2020 ◽  
Author(s):  
Shuichi Hiroyama ◽  
Takemi Rokugawa ◽  
Miwa Ito ◽  
Hitoshi Iimori ◽  
Ippei Morita ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Protein Expression ◽  
Kinetic Analysis ◽  
Hepatic Fibrosis ◽  
Kinetic Modelling ◽  
Left Ventricular ◽  
Emission Tomography ◽  
Histological Evaluation ◽  
Alcoholic Steatohepatitis ◽  
Positron Emission

Abstract Background Integrin αvβ3, which are expressed by activated hepatic stellate cells in non-alcoholic steatohepatitis (NASH), play an important role in the fibrosis. Recently, we reported that an RGD peptide positron emission tomography (PET) probe is useful as a predictor of hepatic fibrosis. Kinetic analysis of the RGD PET probe has been performed in tumours, but not in hepatic fibrosis. Therefore, we aimed to quantify hepatic integrin αvβ3 in a model of NASH by kinetic analysis using 18F-FPP-RGD2, an integrin αvβ3 PET probe.Methods 18F-FPP-RGD2 PET/CT scans were performed in control and NASH rats. Tissue kinetic analyses were performed using a one-tissue, two-compartment (1T2C) and a two-tissue, three-compartment (2T3C) model using an image-derived input function (IDIF) for the left ventricle. We then conducted correlation analysis between standard uptake values (SUVs) or volume of distribution (VT), evaluated using compartment kinetic analysis, and integrin αv or β3 protein expression.Results Biochemical and histological evaluation confirmed the development of NASH rats. Integrin αvβ3 protein expression and hepatic SUV were higher in NASH- than normal rats. The hepatic activity of 18F-FPP-RGD2 peaked rapidly after administration and then gradually decreased, whereas left ventricular activity rapidly disappeared. The 2T3C model was found to be preferable for 18F-FPP-RGD2 kinetic analysis in the liver. The VT (IDIF) for 18F-FPP-RGD2, calculated using the 2T3C model, was significantly higher in NASH- than normal rats and correlated strongly with hepatic integrin αv and β3 protein expression. The strengths of these correlations were similar to those between SUV60–90 min and hepatic integrin αv or β3 protein expression.Conclusions We have demonstrated that the VT (IDIF) of 18F-FPP-RGD2, calculated using kinetic modelling, positively correlates with integrin αv and β3 protein in the liver of NASH rats. These findings suggest that hepatic VT (IDIF) provides a quantitative assessment of integrin αvβ3 protein in liver.

scholarly journals Evaluation of [13N]ammonia positron emission tomography as a potential method for quantifying glutamine synthetase activity in the human brain

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alice Egerton ◽  
Joel T. Dunn ◽  
Nisha Singh ◽  
Zilin Yu ◽  
Jim O’Doherty ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Glutamine Synthetase ◽  
Human Brain ◽  
Kinetic Modelling ◽  
Emission Tomography ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Kinetic Rate Constant ◽  
Arterial Blood ◽  
Positron Emission

Abstract Purpose The conversion of synaptic glutamate to glutamine in astrocytes by glutamine synthetase (GS) is critical to maintaining healthy brain activity and may be disrupted in several brain disorders. As the GS catalysed conversion of glutamate to glutamine requires ammonia, we evaluated whether [13N]ammonia positron emission tomography (PET) could reliability quantify GS activity in humans. Methods In this test–retest study, eight healthy volunteers each received two dynamic [13N]ammonia PET scans on the morning and afternoon of the same day. Each [13N]ammonia scan was preceded by a [15O]water PET scan to account for effects of cerebral blood flow (CBF). Results Concentrations of radioactive metabolites in arterial blood were available for both sessions in five of the eight subjects. Our results demonstrated that kinetic modelling was unable to reliably distinguish estimates of the kinetic rate constant k3 (related to GS activity) from K1 (related to [13N]ammonia brain uptake), and indicated a non-negligible back-flux of [13N] to blood (k2). Model selection favoured a reversible one-tissue compartmental model, and [13N]ammonia K1 correlated reliably (r2 = 0.72–0.92) with [15O]water CBF. Conclusion The [13N]ammonia PET method was unable to reliably estimate GS activity in the human brain but may provide an alternative index of CBF.

scholarly journals ​Quantitative evaluation of hepatic integrin αvβ3 expression by positron-emission tomography imaging using 18F-FPP-RGD2 in rats with non-alcoholic steatohepatitis

2020 ◽  
Author(s):  
Shuichi Hiroyama ◽  
Takemi Rokugawa ◽  
Miwa Ito ◽  
Hitoshi Iimori ◽  
Ippei Morita ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Protein Expression ◽  
Kinetic Analysis ◽  
Hepatic Fibrosis ◽  
Kinetic Modelling ◽  
Left Ventricular ◽  
Emission Tomography ◽  
Histological Evaluation ◽  
Alcoholic Steatohepatitis ◽  
Positron Emission

Abstract Background Integrin αvβ3, which are expressed by activated hepatic stellate cells in non-alcoholic steatohepatitis (NASH), play an important role in the fibrosis. Recently, we reported that an RGD peptide positron emission tomography (PET) probe is useful as a predictor of hepatic fibrosis. Kinetic analysis of the RGD PET probe has been performed in tumours, but not in hepatic fibrosis. Therefore, we aimed to quantify hepatic integrin αvβ3 in a model of NASH by kinetic analysis using 18F-FPP-RGD2, an integrin αvβ3 PET probe.Methods 18F-FPP-RGD2 PET/CT scans were performed in control and NASH rats. Tissue kinetic analyses were performed using a one-tissue, two-compartment (1T2C) and a two-tissue, three-compartment (2T3C) model using an image-derived input function (IDIF) for the left ventricle. We then conducted correlation analysis between standard uptake values (SUVs) or volume of distribution (VT), evaluated using compartment kinetic analysis, and integrin αv or β3 protein expression.Results Biochemical and histological evaluation confirmed the development of NASH rats. Integrin αvβ3 protein expression and hepatic SUV were higher in NASH- than normal rats. The hepatic activity of 18F-FPP-RGD2 peaked rapidly after administration and then gradually decreased, whereas left ventricular activity rapidly disappeared. The 2T3C model was found to be preferable for 18F-FPP-RGD2 kinetic analysis in the liver. The VT (IDIF) for 18F-FPP-RGD2, calculated using the 2T3C model, was significantly higher in NASH- than normal rats and correlated strongly with hepatic integrin αv and β3 protein expression. The strengths of these correlations were similar to those between SUV60–90 min and hepatic integrin αv or β3 protein expression.Conclusions We have demonstrated that the VT (IDIF) of 18F-FPP-RGD2, calculated using kinetic modelling, positively correlates with integrin αv and β3 protein in the liver of NASH rats. These findings suggest that hepatic VT (IDIF) provides a quantitative assessment of integrin αvβ3 protein in liver.

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