scholarly journals Brief Introduction to Gamma Spectroscopy

2021 ◽  
Author(s):  
Lauren Overbay
Keyword(s):  
Gamma Spectroscopy

scholarly journals Development of a blood sample detector for multi-tracer positron emission tomography using gamma spectroscopy

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Carlos Velasco ◽  
Adriana Mota-Cobián ◽  
Jesús Mateo ◽  
Samuel España
Keyword(s):  
Positron Emission Tomography ◽  
Blood Sample ◽  
Pet Imaging ◽  
Spectroscopic Analysis ◽  
Gamma Spectroscopy ◽  
Emission Tomography ◽  
Blood Samples ◽  
Positron Emission

Abstract Background Multi-tracer positron emission tomography (PET) imaging can be accomplished by applying multi-tracer compartment modeling. Recently, a method has been proposed in which the arterial input functions (AIFs) of the multi-tracer PET scan are explicitly derived. For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter. Alternatively, these blood samples required for the spectroscopic analysis may be obtained and analyzed on site by an automated detection device, thus minimizing analysis time and radiation exposure of the operating personnel. In this work, a new automated blood sample detector based on silicon photomultipliers (SiPMs) for single- and multi-tracer PET imaging is presented, characterized, and tested in vitro and in vivo. Results The detector presented in this work stores and analyzes on-the-fly single and coincidence detected events. A sensitivity of 22.6 cps/(kBq/mL) and 1.7 cps/(kBq/mL) was obtained for single and coincidence events respectively. An energy resolution of 35% full-width-half-maximum (FWHM) at 511 keV and a minimum detectable activity of 0.30 ± 0.08 kBq/mL in single mode were obtained. The in vivo AIFs obtained with the detector show an excellent Pearson’s correlation (r = 0.996, p < 0.0001) with the ones obtained from well counter analysis of discrete blood samples. Moreover, in vitro experiments demonstrate the capability of the detector to apply the gamma spectroscopic analysis on a mixture of 68Ga and 18F and separate the individual signal emitted from each one. Conclusions Characterization and in vivo evaluation under realistic experimental conditions showed that the detector proposed in this work offers excellent sensibility and stability. The device also showed to successfully separate individual signals emitted from a mixture of radioisotopes. Therefore, the blood sample detector presented in this study allows fully automatic AIFs measurements during single- and multi-tracer PET studies.

scholarly journals Clinically Applicable Cyclotron-Produced Gallium-68 Gives High-Yield Radiolabeling of DOTA-Based Tracers

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1118
Author(s):  
Emma Jussing ◽  
Stefan Milton ◽  
Erik Samén ◽  
Mohammad Mahdi Moein ◽  
Lovisa Bylund ◽  
...  
Keyword(s):  
Metal Ion ◽  
Metal Content ◽  
Gamma Spectroscopy ◽  
Radiochemical Yield ◽  
High Yield ◽  
Automated Synthesis ◽  
Molar Activity ◽  
Icp Ms ◽  
Gallium 68 ◽  
Fe Impurities

By using solid targets in medical cyclotrons, it is possible to produce large amounts of 68GaCl3. Purification of Ga3+ from metal ion impurities is a critical step, as these metals compete with Ga3+ in the complexation with different chelators, which negatively affects the radiolabeling yields. In this work, we significantly lowered the level of iron (Fe) impurities by adding ascorbate in the purification, and the resulting 68GaCl3could be utilized for high-yield radiolabeling of clinically relevant DOTA-based tracers. 68GaCl3 was cyclotron-produced and purified with ascorbate added in the wash solutions through the UTEVA resins. The 68Ga eluate was analyzed for radionuclidic purity (RNP) by gamma spectroscopy, metal content by ICP-MS, and by titrations with the chelators DOTA, NOTA, and HBED. The 68GaCl3eluate was utilized for GMP-radiolabeling of the DOTA-based tracers DOTATOC and FAPI-46 using an automated synthesis module. DOTA chelator titrations gave an apparent molar activity (AMA) of 491 ± 204 GBq/µmol. GMP-compliant syntheses yielded up to 7 GBq/batch [68Ga]Ga-DOTATOC and [68Ga]Ga-FAPI-46 (radiochemical yield, RCY ~ 60%, corresponding to ten times higher compared to generator-based productions). Full quality control (QC) of 68Ga-labelled tracers showed radiochemically pure and stable products at least four hours from end-of-synthesis.

scholarly journals Transparent ceramic scintillators for gamma spectroscopy and radiography

2010 ◽  
Author(s):  
N. J. Cherepy ◽  
J. D. Kuntz ◽  
Z. M. Seeley ◽  
S. E. Fisher ◽  
O. B. Drury ◽  
...  
Keyword(s):  
Gamma Spectroscopy ◽  
Transparent Ceramic

Measuring and Mapping Potassium in Agricultural Fields using Gamma Spectroscopy

2021 ◽  
pp. 1-1
Author(s):  
A. Kavetskiy ◽  
G. Yakubova ◽  
N. Sargsyan ◽  
S. A. Prior ◽  
H. A Torbert ◽  
...  
Keyword(s):  
Gamma Spectroscopy ◽  
Agricultural Fields

DETERMINING THE DENSITY OF MULTIPLE LAYERS USING GAMMA SPECTROSCOPY

2021 ◽  
Author(s):  
Mayir Mamtimin ◽  
◽  
Jeffrey Crawford ◽  
Keyword(s):  
Gamma Spectroscopy ◽  
Laboratory Data ◽  
Hole Density ◽  
Radial Density ◽  
New Approach ◽  
Simulation Tools ◽  
Radial Density Profile ◽  
Gamma Density ◽  
Open Hole

Due to the volumetric nature of the physics and the measurement, traditional gamma-gamma density tools measure an average bulk density of the formation. However, a bulk measurement is not adequate for certain applications where a more detailed resolution of a radial density profile is necessary. In this paper, a new approach of gamma spectral analysis is introduced focusing on the main Compton scattering angles. Several energy windows are linked to the unique radial layers based on scattering angles and location of interaction. As a result, the density of multiple layers can be calculated. The paper first outlines the main principles and analytical structures to formulate two methods to measure layer densities. Then computer simulation tools are used to simulate realistic tool configuration and measurement response to validate and benchmark efficacies of the outlined methods. Finally, a case study is presented to demonstrate the applicability of these methods using laboratory data. The paper is concluded with a list of other possible applications such as open-hole density and behind-pipe evaluation where layer density can provide more details for the analysis.

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