8 results on '"*SINGLE-photon emission computed tomography"'
Search Results
2. Péptidos inhibidores del PSMA radiomarcados para el estudio del carcinoma de próstata.
- Author
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Perera Pintado, Alejandro, Prats Capote, Anaís, and Cruz Arencibia, Jorge
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SINGLE-photon emission computed tomography , *PROSTATE-specific antigen , *POSITRON emission tomography , *NUCLEAR medicine , *PROSTATE cancer , *EARLY diagnosis , *ANDROGEN receptors - Abstract
Prostate cancer, with a high incidence and as the second cause of death among the male population, constitutes a serious health problem that worsens over the years. The early diagnosis and the correct staging of this disease are important for the adequate management of the patient. In this sense, Nuclear Medicine molecular imaging is very useful, so the development of new peptidomimetic molecules with affinity for membrane receptors overexpressed in prostate cancer, such as prostate specific antigen (PSMA), has allowed making a qualitative step forward for the early detection and monitoring of prostate carcinoma. The present work is aimed at providing an overview of the status of PSMA inhibitor peptides, derived from the sequence -Lys-Urea-Glu-, as radiopharmaceuticals for the study of prostate neoplasms, which are currently in different stages of development, showing, in general, a high specificity, an adequate uptake into the tumor tissue and a satisfactory pharmacokinetics, to be used in the study of prostate cancer, both by positron emission tomography (PET), and by single photon emission computed tomography (SPECT). [ABSTRACT FROM AUTHOR]
- Published
- 2022
3. Aporte de la corrección de dispersión por Tomografía para la estimación de actividad en estudios híbridos del tiroides con 131I.
- Author
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Machado López, Katlyn, López Díaz, Adlin, Robaina León, Yalaina, Martín Escuela, Juan Miguel, and Fernández Rodríguez, Viviana M.
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SINGLE-photon emission computed tomography , *TOMOGRAPHY , *BIAS correction (Topology) , *THYROID gland , *HYPERTHYROIDISM - Abstract
Hyperthyroidism is one of the most frequent MN treatments; however, quantification of 131I activity in thyroid using Single Photon Computer Tomography (SPECT) and combined with Computer Tomography (SPECT/CT techniques has almost no bibliographic history. This work studied the impact on 131I activity accuracy quantification of scatter corrections using CT information. Three sources of known activity were used for the calibration process (1.06 MBq 2.61 MBq and 4.66 MBq) with a typical uncertainty of 2.4 % and the classic thyroid phantom. The calibration factors and their uncertainty were calculated for each case. To analyze the accuracy of the system, a set of 11 sources (with activities between 1.37 MBq-3.92 MBq) were calculated and the uncertainty was estimated in each case. The relative discrepancies of the calculated activity versus reference were compared (p<0.05). The lowest average discrepancy resulted was 3 % (from 5 to 7 %) corresponding with any correction using CT. The uncertainties were found in the range of 9 to 11 %, being consistent with the discrepancies already found. Conclusions: The corrections of attenuation and dispersion by MC using CT information did not improve the 131I activity quantification accuracy in the geometry of classical thyroid phantom; although it is recommended to expand the range of masses of the thyroid to better represent the wide specific patient clinical situation and confirm these results. [ABSTRACT FROM AUTHOR]
- Published
- 2022
4. Evaluación de un método para estudios de optimización de la exposición médica en medicina nuclear.
- Author
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Batista García-Ramó, Karla, Reyes González, Yudmila, Torres Aroche, Leonel A., and Sánchez González, Yolaine
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SINGLE-photon emission computed tomography , *RADIATION exposure , *SIGNAL generators , *NUCLEAR medicine , *RADIATION doses , *DIAGNOSIS methods , *IONIZING radiation , *ELECTROSTATIC discharges - Abstract
Nuclear medicine (NM) diagnostic procedures use ionizing radiation and it is necessary to ensure that the amount of prescribed activity is as low as reasonably achievable. Optimizing these procedures, one of the greatest challenges facing Nuclear Medicine today, is based on achieving a balance between image quality and radiation dose. The objective of this article is to establish and validate a method for optimization studies of medical exposure in NM simulating different levels of activity that can be applied in patients without violating the ethical and radiological protection principles. The method is based on the recombination of data obtained in gated acquisitions to simulate activity levels. For this, measurements were made using different phantoms and a signal generator. A python code was developed that allows the different activity levels to be simulated automatically from a single gated acquisition and returns the studies in the same dicom format to be reconstructed in the registered processing program provided by the manufacturer. To validate our method, the linear dependence of the number of total counts with the simulated activity levels was demonstrated and the quality of the reconstructed images vs the simulated activity levels was qualitatively evaluated. This method constitutes a valid and applicable proposal in the majority of nuclear medicine services in the country to implement optimization procedures for SPECT studies, contributing to a reduction in population exposure to radiation, due to high-tech diagnostic tests. [ABSTRACT FROM AUTHOR]
- Published
- 2022
5. Niveles de referencia para diagnóstico en medicina nuclear e imagen híbrida. Revisión y actualización.
- Author
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Amador Balbona, Zayda H., López Díaz, Adlin, and Torres Aroche, Leonel A.
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SINGLE-photon emission computed tomography , *RADIATION protection , *NUCLEAR medicine , *DIAGNOSTIC imaging , *PROFESSIONAL associations , *GOVERNMENT agencies - Abstract
The diagnostic image must be carried out with the minimum necessary exposure of the patient that allows the objective of the diagnosis to be satisfactorily achieved. For this reason, diagnostic reference levels emerge and are established as dynamic tools to help optimize radiation protection, contribute to the standardization of practices and strengthen culture of safety, without compromising the clinical purpose of each examination or process. The objective of this work is to provide an updated overview of the establishment and use of these levels for nuclear medicine and hybrid imaging. It is identified that to establish and use them properly, trained personnel and coordination and collaboration activities are required among multiple actors, including medical services, health authorities, professional organizations and regulatory bodies. The accelerated development of technology generally exceeds the change in regulations, so these levels must be updated periodically, in order to fulfil their role as a guide and spur for optimization. The worldwide expansion of hybrid technologies and their growing use are a phenomenon of the last decade, so the establishment of these levels for such technologies has not been consolidated, although countries such as the United Kingdom and Australia show solid steps in this address. Research has been carried out with phantoms and directly with patients, the latter with a more useful contribution of information. The installation of hybrid equipment in Cuba demands this study, hence its importance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
6. Estudio de los indicadores de dosis por tomografía computada en un sistema híbrido SPECT/CT: resultados preliminares.
- Author
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López Díaz, Adlin, del Pozo Almaguer, Armando, Machado Tejeda, Adalberto, Martín Escuela, Juan Miguel, Batista Ramó, Karla, Torres Aroche, Leonel Alberto, Calderón Marín, Carlos Fabián, and Fernández Rondón, Manuel
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SINGLE-photon emission computed tomography , *IMAGING systems , *HYBRID systems , *RADIATION doses , *NUCLEAR medicine , *COLLIMATORS - Abstract
The introduction in Cuba of imaging hybrid systems in nuclear medicine has become a challenge for medical physicist in order to guaranty the patient´s radiation safety and proper dose estimation. The aim of this study was to retrospectively evaluate the CT radiation doses for studies performed with a SPECT/CT hybrid system (SPECT/CT). A MATLAB “in house” made tool was tested and validated for this purpose. 62 patients with CT studies were manually and automatically reviewed; the tool could visualize and properly recover the patient personal information, CT protocol and dose related data from the DICOM header in the SPECT/CT study file. The CT volume dose index (CTDIvol) parameter was used for calculating the CT dose-length product (DPL) and the effective doses (E). The CT radiation dose preliminary results were on the range of those reported by others authors for the typical studies, demonstrating the efficacy of the tool developed and the CT dose assessment method. [ABSTRACT FROM AUTHOR]
- Published
- 2022
7. Asociación de los resultados positivos del SPECT de perfusión miocárdica con 99mTc-MIBI, con la presencia de dislipidemia en pacientes ≥ 40 años de edad.
- Author
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Rochela Vázquez, Luis Manuel, Peix González, Amalia, Batista Cuellar, Juan F., Romero Collado, Susana, Oviedo Pérez, Lourdes, Fernández-Britto, José E., Peña Quián, Yamilé, and Hernández Cairo, Abel
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SINGLE-photon emission computed tomography , *DYSLIPIDEMIA , *MYOCARDIAL reperfusion , *BODY mass index , *COMPARATIVE studies , *PATIENT safety , *TECHNETIUM isotopes , *PATIENTS - Abstract
The paper is aimed at establishing the association of the dyslipidemia with the positive results of the myocardial perfusion SPECT, for the optimization of use. 152 MPSPECT were analyzed, different days, for an average age of 58.32 years, 86 (56.6%), were males. Considering the presence of dyslipidemia, the patients were divided into two groups: dyslipidemia, n = 37(24.3%) and not-dyslipidemia, n = 115 (75.7%). No significant differences were present in the age average (59.59/57.90, p = 0.284), in the body mass index (24.85/25.03, p=0.739), nor in the frequency of mature. Therefore, only dyslipidemia contributes to therefore the additional risk. Result: 102 (67.1%) MPSPECT were positive. In the comparison among groups no significant difference in the incidence of positive results was observed (67.60/67.00, p = 0.945), and the same situation remained when the groups were subdivided into symptomatic and asymptomatic. As a result of the study, it was concluded that dyslipidemia does not represent a significant risk of ischemic cardiopathy in patients within the ages of risk, therefore there is no significant association with the positive results of the SPECTPM, within patients in ages of risk. [ABSTRACT FROM AUTHOR]
- Published
- 2012
8. Análisis comparativo de la sensibilidad del escáner rSPECT usando GAMOS: nueva interfaz de Geant4.
- Author
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Martínez Turtós, Rosana, Díaz García, Angelina, Abreu Alfonso, Yamiel, Arteche, Jossué, and Leyva Pernía, Diana
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SINGLE-photon emission computed tomography , *COMPARATIVE studies , *MONTE Carlo method , *MEDICAL imaging systems , *NUCLEAR medicine , *SIMULATION methods & models - Abstract
The molecular imaging of in vivo cellular processes using preclinical animal studies and SPECT technique is one of the main reasons for the design of new devices with high spatial resolution. As an auxiliary tool, Monte Carlo simulation has allowed the effective characterization and optimization of those medical imaging systems. At present there is a new simulation framework called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations); which code, libraries and particle transport method correspond to those developed by GEANT4 and contains specific applications for nuclear medicine. This tool has been already validated for PET technique by comparison with experimental data, while not yet been done the correct evaluation of GAMOS for SPECT systems. Present work have demonstrated the potential of GAMOS in obtaining simulated realistic data using this nuclear imaging technique. For this purpose, simulation of a novel installation "rSPECT", devote to study rodents, has been done. The study comprises the collimation and detection geometries and the fundamental characteristics of the previuos published experimental measurements for rSPECT installation. Studies have been done using 99mTc and 20% energy window. Sensitivity values obtained by simulation revealed an acceptable agreement with experimental values. Therefore we can conclude that simulation results have shown good agreement with the real data. This fact allowed us to estimate the behavior of the new GEANT4 simulation platform "GAMOS" in SPECT applications and have demonstrated the feasibility of reproducing experimental data. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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