نتایج جستجو برای: spect slit slat collimator

تعداد نتایج: 23367  

Journal: :Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 2016

Journal: :Physics in medicine and biology 1999
D J Kadrmas E C Frey B M Tsui

Simultaneous acquisition of dual-isotope SPECT data offers a number of advantages over separately acquired data; however, simultaneous acquisition can result in cross-contamination between isotopes. In this work we propose and evaluate two frameworks for iterative model-based compensation of cross-contamination in dual-isotope SPECT. The methods were applied to cardiac imaging with technetium-9...

Journal: :Journal of Instrumentation 2022

A high sensitivity Cardiac SPECT system using curved crystals with pinhole collimation was proposed previously (Dey, IEEE TNS 2012, Bhusal et al, Med. Phys. 2019). Here, we hypothesize that a curvature hemi-ellipsoid detector results in measurable differences light distribution from events at different depths the crystal. This tested by analyzing scintillation Monte-Carlo (Geant4) and evaluatio...

Journal: :Journal of medical and biological engineering 2016
Zhiping Mu Lawrence W Dobrucki Yi-Hwa Liu

The imaging of distributed sources with near-field coded aperture (CA) remains extremely challenging and is broadly considered unsuitable for single-photon emission computerized tomography (SPECT). This study proposes a novel CA SPECT reconstruction approach and evaluates the feasibilities of imaging and reconstructing distributed hot sources and cold lesions using near-field CA collimation and...

2015
Pernilla Norberg Anna Olsson Gudrun Alm Carlsson Michael Sandborg Agnetha Gustafsson

BACKGROUND The amount of inhomogeneities in a (99m)Tc Technegas single-photon emission computed tomography (SPECT) lung image, caused by reduced ventilation in lung regions affected by chronic obstructive pulmonary disease (COPD), is correlated to disease advancement. A quantitative analysis method, the CVT method, measuring these inhomogeneities was proposed in earlier work. To detect mild COP...

2014
Norikazu Matsutomo Akio Nagaki Masayuki Sasaki

OBJECTIVES IQ-SPECT is an advanced high-speed SPECT modality for myocardial perfusion imaging (MPI), which uses a multi-focus fan beam collimator with resolution recovery reconstruction. The aim of this study was to compare IQ-SPECT with conventional SPECT in terms of performance, based on standard clinical protocols. In addition, we examined the concordance between conventional and IQ_SPECT in...

2008
S. H. Ha M. J. Hamamura W. W. Roeck O. Nalcioglu D. J. Wagenaar D. Meier B. E. Patt

Purpose: Most of the nuclear imaging systems, especially those that are based on single photon emission detection, require the use of a collimatorusually made out of lead (Pb) or some other high Z material such as tungsten (W). Even some PET systems employ some sort of slat-septa collimation, although the important part of PET image formation is done electronically via coincidence detection. Mu...

2011
Astrid Rakow

The Flap/Slat Controller benchmark is derived from a case study for Airbus [1]. During take-off (and landing) flaps and slats of the aircraft are extended to generate more lift at low velocity and have to be retracted in time as they are not robust enough for high velocities. Our system model is scalable in the number of flaps/slats, which allows us to study scalability of our methods on system...

Journal: :Journal of animal science 2015
M R P Elmore M F Elischer M C Claeys E A Pajor

Raising beef cattle on concrete floors can negatively impact their welfare by increasing joint swelling and body lesions, as well as abnormalities in resting behavior and postural changes. We hypothesized that the addition of rubber mats to concrete pens would improve beef cattle welfare by improving performance, health, hygiene, and resting behavior. Forty-eight crossbred Angus steers were hou...

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