نتایج جستجو برای: scatter correction

تعداد نتایج: 176847  

2008
Vahid Changizi Abbas Takavar Azadeh Babakhani Mahdi Sohrabi

Radionuclide imaging has the potential to be used in quantitative analysis of the regional function of organs. However, quantification of SPECT images is degraded by many factors such as Compton photon scattering. This could have a destructive effect on clinical reports so it is important to do scatter correction to get better quality SPECT images. We intended to determine how scatter correctio...

2017
Thorsten Heußer Philipp Mann Christopher M Rank Martin Schäfer Antonia Dimitrakopoulou-Strauss Heinz-Peter Schlemmer Boris A Hadaschik Klaus Kopka Peter Bachert Marc Kachelrieß Martin T Freitag

OBJECTIVES Combined positron emission tomography (PET) and magnetic resonance imaging (MRI) targeting the prostate-specific membrane antigen (PSMA) with a 68Ga-labelled PSMA-analog (68Ga-PSMA-11) is discussed as a promising diagnostic method for patients with suspicion or history of prostate cancer. One potential drawback of this method are severe photopenic (halo-) artifacts surrounding the bl...

Introduction: In radionuclide imaging, object scatter is one of the major factors leading to image quality degradation. Therefore, the correction of scattered photons might have a great impact on improving the image quality. Regarding this, the present study aimed to determine the main and sub-energy windows for triple energy window (TEW) scatter correction method usin...

Jalil Pirayesh Islamian Mahdi Momennezhad Mohammad Taghi Bahreyni Toossi, Ramin Sadeghi Seyyed Rasool Zakavi

Introduction SPECT projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. Backscatter constitutes a major part of the scatter contamination in lower energy windows. The current study is an evaluation of the effect of backscatter material on FWHM and image quality investigated by Monte Carlo simulation. Materials and Methods SIMIND program...

Journal: :Journal of nuclear medicine technology 2005
Masuo Hayashi Jun Deguchi Keita Utsunomiya Makoto Yamada Tsuyoshi Komori Masayasu Takeuchi Kensei Kanna Isamu Narabayashi

OBJECTIVE The radioactivity count distribution in the brain must be determined accurately to accurately measure cerebral blood flow (CBF). Scatter and attenuation are factors that compromise the accuracy of determining radioactivity counts in the brain. METHODS We compared regional CBF in patients by an autoradiographic method using N-isopropyl-p-[123I] iodoamphetamine when, first, attenuatio...

2002
Kenneth F. Koral

Detection of gamma rays which Compton scatter within a patient but are still within the photopeak window of the Anger camera leads to inaccuracies in quantification of radioactivity from nuclear-medicine images. With the dual-energy-window correction method and a single (universal) scatter multiplier, the activity error is relatively large when there is tissue background with a large range of v...

Journal: :Physics in medicine and biology 2011
Brian F Hutton Irène Buvat Freek J Beekman

Detection of scattered gamma quanta degrades image contrast and quantitative accuracy of single-photon emission computed tomography (SPECT) imaging. This paper reviews methods to characterize and model scatter in SPECT and correct for its image degrading effects, both for clinical and small animal SPECT. Traditionally scatter correction methods were limited in accuracy, noise properties and/or ...

2013
Hsin-Hui Lee Jyh-Cheng Chen

The quantitative accuracy of SPECT is limited by photon attenuation and scatter effect when photons interact with atoms. In this study, we developed a new attenuation correction (AC) method, CT-based mean attenuation correction (CTMAC) method, and compared it with various methods that were often used currently to assess the AC phenomenon by using the small-animal SPECT/CT data that were acquire...

Journal: :iranian journal of medical physics 0
mohammad taghi bahreyni toossi medical physics research center, medical physics department, mashhad university of medical sciences, mashhad, iran

introduction spect projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. backscatter constitutes a major part of the scatter contamination in lower energy windows. the current study is an evaluation of the effect of backscatter material on fwhm and image quality investigated by monte carlo simulation. materials and methods simind program...

2002
P. Bristow A. Alexov F. Kerber M. Rosa

The dark flux correction step of the Faint Object Spectrograph calibration pipeline was investigated with the joint aims of applying a more physical model and improving the performance of the pipeline. After processing with the original calfos pipeline, dark calibration data shows a large scatter in count rates. We were able to reduce this scatter to some extent by scaling the correction accord...

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