نتایج جستجو برای: phantom scatter factor

تعداد نتایج: 870740  

Journal: :Chinese Physics 2021

A algorithm of obtaining absolute dose at each tissue depth only by the mathematical calculation formula is reported. The based on integrating energy flux electron generated X-ray in range irradiation field, and spectrum ray secondary scattered are considered this process. In algorithm, water phantom field divided into several thin layers, electrons interaction between layer reaching point calc...

2014
Robin de Nijs Vera Lagerburg Thomas L. Klausen Søren Holm

PURPOSE Patient-specific dosimetry of lutetium-177 ((177)Lu)-DOTATATE treatment in neuroendocrine tumours is important, because uptake differs across patients. Single photon emission computer tomography (SPECT)-based dosimetry requires a conversion factor between the obtained counts and the activity, which depends on the collimator type, the utilized energy windows and the applied scatter corre...

2011
Rameshwar Prasad Habib Zaidi

The objective of this study is to characterize the performance of the preclinical avalanche photodiode (APD)based LabPET-8TM subsystem of the fully integrated trimodality PET/SPECT/CT TriumphTM scanner using the NEMA NU 04 – 2008 protocol. The characterized performance parameters include the spatial resolution, sensitivity, scatter fraction, counts rate performance, and image quality characteri...

Journal: :Physics in medicine and biology 2011
Rameshwar Prasad Osman Ratib Habib Zaidi

The objective of this study is to characterize the performance of the preclinical avalanche photodiode (APD)-based LabPET-8™ subsystem of the fully integrated trimodality PET/SPECT/CT Triumph™ scanner using the National Electrical Manufacturers Association (NEMA) NU 04-2008 protocol. The characterized performance parameters include the spatial resolution, sensitivity, scatter fraction, counts r...

Introduction: Myocardial perfusion imaging is a nuclear medicine imaging method that is used to detect coronary artery diseases. One of the main sources of error in this imaging method is the detection of Compton scattered photons in the photopeak energy window used for data acquisition. This results in the degradation of the image contrast, and therefore decreases the...

2011
Stephan Walrand Michel Hesse Georges Demonceau Stanislas Pauwels François Jamar

BACKGROUND The purpose of the study is to evaluate whether a pinhole collimator is better adapted to bremsstrahlung single photon emission computed tomography [SPECT] than parallel-hole collimators and in the affirmative, to evaluate whether pinhole bremsstrahlung SPECT, including a simple model of the scatter inside the patient, could provide a fast dosimetry assessment in liver selective inte...

Journal: :Journal of nuclear medicine technology 2009
Yan Yan Gengsheng Lawrence Zeng

UNLABELLED Attenuation, scatter, and blurring are 3 major contributors to SPECT image degradation. Image reconstruction without compensation for these degradations results in reduced contrast and reduced quantitative accuracy. In this proof-of-concept study, we present an efficient postprocessing method to compensate for the scatter and blurring effect in SPECT. METHODS A raw image is first r...

Journal: :Journal of vascular and interventional radiology : JVIR 2006
Sergio Dromi Bradford J Wood Jay Oberoi Ziv Neeman

Significant direct and scatter radiation doses to patient and physician may result from routine interventional radiology practice. A lead-free disposable tungsten antimony shielding pad was tested in phantom patients during simulated diagnostic angiography procedures. Although the exact risk of low doses of ionizing radiation is unknown, dramatic dose reductions can be seen with routine use of ...

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