نتایج جستجو برای: scatter correction

تعداد نتایج: 176847  

Journal: :Medical physics 2009
Lei Zhu Yaoqin Xie Jing Wang Lei Xing

Cone-beam CT (CBCT) is being increasingly used in modern radiation therapy for patient setup and adaptive replanning. However, due to the large volume of x-ray illumination, scatter becomes a rather serious problem and is considered as one of the fundamental limitations of CBCT image quality. Many scatter correction algorithms have been proposed in literature, while a standard practical solutio...

Journal: :Tsinghua Science and Technology 2010

2010

ID: 14214 Title: A novel scatter reduction and correction method to improve cone-beam CT (CBCT) image quality Purpose: To develop a novel scatter reduction and correction method to improve the CBCT image quality for IGRT applications. Method and Materials: A one-dimensional grid composed of lead with equal interspacing was positioned between the x-ray source and the imaging object during CBCT a...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 1998
P Maksud B Fertil C Rica G El Fakhri A Aurengo

UNLABELLED This study investigates the ability of artificial neural networks (ANN) to simultaneously correct for attenuation and Compton scattering in scintigraphic imaging. METHODS Three sets of experiments are conducted using images of radioactive sources with various shapes and distributions in a homogeneous medium. Numerical Monte Carlo simulations and physical phantom acquisitions of rad...

Ahmad Bitarafan Rajabi Bijan Hashemi Malayeri Fereidoon Rastgoo Hassan Firoozabadi Hossein Rajabi, Nahid Yaghoobi Nasrollah Jabbari

Introduction: Scatter radiation is one of the major sources of error in nuclear medicine data processing. Different methods of scatter correction have been introduced in order to improve the quality of data. However the best method is to avoid recording of scatter photons in acquisition. The only difference between scattered and non-scattered photons is the energy. Pulse height analyzer i...

2010
Ekta Dharaiya Richard A. Thompson Matthias Bertram

Traditionally, most MDCT systems employ a post collimation anti-scatter grid (ASG) in the angular (X) direction to compensate for the scatter radiation. However, with increasing Z-axis coverage offered by advanced state-of-the-art multi-slice CT (MSCT) scanners, the scatter level increases significantly and there is an opportunity to use software algorithms to further decrease the impact of sca...

2012
Nadège Anizan Thomas Carlier Cecilia Hindorf Jacques Barbet

Background: Noninvasive multimodality imaging is essential for preclinical evaluation of the biodistribution and pharmacokinetics of radionuclide therapy and for monitoring tumor response. Imaging with nonstandard positronemission tomography [PET] isotopes such as I is promising in that context but requires accurate activity quantification. The decay scheme of I implies an optimization of both ...

Journal: :Annals of nuclear medicine 2001
H Kado H Iida H Kimura T Ogawa Y Narita J Hatazawa T Tsuchida Y Yonekura H Itoh

To evaluate the usefulness of a combination of linearization and scatter-attenuation correction on 99mTc-bicisate (ECD)-single photon emission tomographic (SPECT) images, both cerebral blood flow (CBF)-positron emission tomographic (PET) images and ECD-SPECT images from fifteen patients with chronic cerebral infarction were acquired. We measured radioactivity counts in regions of interest (ROIs...

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