نتایج جستجو برای: phantom spect imaging system

تعداد نتایج: 2623550  

Objective: The aim of this study was to evaluate the influences of reconstruction and attenuation correction on the differences in the radioactivity distributions in 123I brain SPECT obtained by the hybrid SPECT/CT device. Methods: We used the 3-dimensional (3D) brain phantom, which imitates the precise structure of gray mater, white matter and bone regions. It was filled with 123I solution (20...

Journal: :Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging 2004
William P Segars Benjamin M W Tsui Eric C Frey G Allan Johnson Stuart S Berr

PURPOSE We develop a realistic and flexible 4-D digital mouse phantom and investigate its usefulness in molecular imaging research. METHODS Organ shapes were modeled with non-uniform rational B-spline (NURBS) surfaces based on high-resolution 3-D magnetic resonance microscopy (MRM) data. Cardiac and respiratory motions were modeled based on gated magnetic resonance imaging (MRI) data obtained...

A. Vahidian Kamyad, M. Hajizadeh Saffar, M. Naji Midani, M.H. Noori Eskandari,

Background: Photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of SPECT images and results to errors in accuracy of quantitative measurements. This can be corrected via different physical or mathematical approaches. As the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘Piece ...

2013
Chao Wu Hugo A Gratama van Andel Peter Laverman Otto C Boerman Freek J Beekman

UNLABELLED BACKGROUND In single-photon emission computed tomography (SPECT), attenuation of photon flux in tissue affects quantitative accuracy of reconstructed images. Attenuation maps derived from X-ray computed tomography (CT) can be employed for attenuation correction. The attenuation coefficients as well as registration accuracy between SPECT and CT can be influenced by several factors....

Journal: :iranian journal of nuclear medicine 2014
mahsa noori asl alireza sadremomtaz

the diagnostic accuracy of single photon emission computed tomography (spect) is profoundly influenced by attenuation phenomenon. soft tissue attenuation degrades cardiac spect image quality, thereby decreasing the possibility of the detection of the lesions. a variety of correction techniques based on different assumptions have been used to reduce the impact of attenuation. several types of sy...

2006
Iván Valastyán

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Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2008
Christian Goetz Elodie Breton Philippe Choquet Vincent Israel-Jost André Constantinesco

UNLABELLED Localization of regions with increased uptake of radiotracer in small-animal SPECT is greatly facilitated when using coregistration with anatomic images of the same animal. As MRI has several advantages compared with CT (soft-tissue contrast and lack of ionizing radiation) we developed a SPECT/low-field MRI hybrid device for small-animal imaging. METHODS A small-animal single-pinho...

Journal: :Frontiers in nuclear medicine 2021

Objective: An image display with a standardized uptake value (SUV) scale is recommended for analyzing PET exams, thus requiring the reconstruction of accurate images both SUV measurement and visual analysis. This study aimed to determine whether such may also be obtained high-speed CZT-SPECT/CT system, further application longitudinal monitoring vertebral fractures. Materials Methods: SPECT was...

Journal: :iranian journal of nuclear medicine 2008
mohsen hajizadeh seyed rasoul zakavi mehdi momen-nejad maryam naji

introduction: ordered subset expectation maximization (osem), is an effective iterative method for spect image reconstruction. the aim of this study is the evaluation of the role of system matrix in osem image reconstruction method using four different physical beam radiation models with three detection configurations. methods: spect was done with an arc of 180 degree in 32 projections after i...

2017
Kenichi Nakajima Koichi Okuda Kunihiko Yokoyama Tatsuya Yoneyama Shiro Tsuji Hiroyuki Oda Mitsuhiro Yoshita Koji Kubota

BACKGROUND Cardiac 123I-meta-iodobenzylguanidine (MIBG) uptake is quantified using the heart-to-mediastinum ratio (HMR) with an Anger camera. The relationship between HMR determined using D-SPECT with a cadmium-zinc-telluride detector and an Anger camera is not fully understood. Therefore, the present study aimed to define this relationship using images derived from a phantom and from patients....

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