نتایج جستجو برای: digital ncat phantom

تعداد نتایج: 324200  

Journal: :Medical engineering & physics 2011
Jing Tang W Paul Segars Taek-Soo Lee Xin He Arman Rahmim Benjamin M W Tsui

Quantitative description of cardiac motion is desirable to assist in detecting myocardial abnormalities from gated myocardial perfusion (GMP) emission computed tomography (ECT) images. While "optical flow" type of cardiac motion estimation (ME) techniques have been developed in the past, there has been no quantitative evaluation of their performance. Moreover, no investigation has been performe...

Ahmad Bitarafan, Faraz Kalantari Hossein Rajabi, Nahid Yaghoobi

Introduction: It is a common protocol to use 201Tl for the rest and 99mTc for the stress cardiac SPECT imaging. Theoretically, both types of imaging may be performed simultaneously using different energy windows for each radionuclide. However, a potential limitation is the cross-contamination of scattered photons from 99mTc and collimator X-rays into the 201Tl energy window. We used a middle en...

2014
Mana Akamatsu Yasuo Yamashita Go Akamatsu Yuji Tsutsui Nobuyoshi Ohya Yasuhiko Nakamura Masayuki Sasaki

OBJECTIVES The aim of this study was to evaluate the influences of reconstruction and attenuation correction on the differences in the radioactivity distributions in (123)I 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 matter, white matter and bone regions. It was filled with (123)I soluti...

Journal: :Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology 2005
Tracy L Faber Jan Modersitzki Russell D Folks Ernest V Garcia

BACKGROUND New algorithms were evaluated for their efficacy in detecting and quantifying serial changes in myocardial perfusion from single photon emission computed tomography (SPECT). METHODS AND RESULTS We generated 72 simulations with various left ventricular positions, sizes, count rates, and perfusion defect severities using the nonuniform rational B-splines (NURBs)-based CArdiac Torso (...

2006
Katsuyuki Taguchi W. Paul Segars George S.K. Fung Benjamin M.W. Tsui Russell H. Morgan

Coronary artery imaging with multi-slice helical computed tomography is a promising noninvasive imaging technique. The current major issues include the insufficient temporal resolution and large patient dose. We propose an image reconstruction method which provides a solution to both of the problems. The method uses an iterative approach repeating the following four steps until the difference b...

2012
Tuija Kangasmaa Jyrki Kuikka Antti Sohlberg

Simultaneous Tl-201/Tc-99m dual isotope myocardial perfusion SPECT is seriously hampered by down-scatter from Tc-99m into the Tl-201 energy window. This paper presents and optimises the ordered-subsets-expectation-maximisation-(OS-EM-) based reconstruction algorithm, which corrects the down-scatter using an efficient Monte Carlo (MC) simulator. The algorithm starts by first reconstructing the T...

Journal: :Journal of magnetic resonance imaging : JMRI 2011
Nolan E Swailes Matthew Ethan MacDonald Richard Frayne

PURPOSE To develop an anthropomorphic phantom to simulate heart, lung, and blood motion. Magnetic resonance imaging (MRI) is sensitive to image distortion and artifacts caused by motion. Imaging phantoms are used to test new sequences, but generally, these phantoms lack physiological motion. For the validation of new MR-based endovascular interventional and other techniques, we developed a dyna...

Journal: :Frontiers in bioscience : a journal and virtual library 1996
A Visweswaran H Liu L L Fajardo G A DeAngelis

In this investigation, we imaged a standard breast phantom and compared the contrast detail curves from a prototype full breast digital mammography system with the corresponding curves for a conventional, analog screen-film system. The full breast digital system exhibited superior contrast detail detectability. The results from this study will be used to plan future clinical evaluations compari...

Objective(s): Alternative normalization methods were proposed to solve the biased information of SPM in the study of neurodegenerative disease. The objective of this study was to determine the most suitable count normalization method for SPM analysis of a neurodegenerative disease based on the results of different count normalization methods applied on a prepared digital phantom similar to one ...

Digital Breast Tomosynthesis (DBT) is a technology that creates three dimensional (3D) images of breast tissue. Tomosynthesis mammography detects lesions that are not detectable with other imaging systems. If image reconstruction time is in the order of seconds, we can use Tomosynthesis systems to perform Tomosynthesis-guided Interventional procedures. This research has been designed to study u...

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