نتایج جستجو برای: spect image

تعداد نتایج: 386253  

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: :iranian journal of nuclear medicine 2008
maryam naji seyed rasoul zakavi mohsen hajizadeh mehdi momennezhad

introduction: attenuation correction is a useful process for improving myocardial perfusion spect and is dependent on activity and distribution of attenuation coefficients in the body (attenuation map). attenuation artifacts are a common problem in myocardial perfusion spect. the aim of this study was to compare the effect of attenuation correction using different attenuation maps and different...

Objective(s): In heart failure, the heart-to-mediastinum (H/M) ratio of the delayed image and washout rate (WR) are well-known as a powerful cardiac event predictors. H/M ratio quantifies the accumulation rate of MIBG in the myocardium and WR quantifies reduction of meta-iodobenzylguanidine (MIBG) accumulation in the heart from the early planar image to the delayed pla...

Journal: :Nihon Hoshasen Gijutsu Gakkai zasshi 2006
Yona Oishi Hideyuki Iwanaga Kazuyoshi Suga Ryoko Ide Akiyo Shimizu Akira Inoue Masahiro Koike

In traditional pulmonary perfusion single photon emission computed tomography (SPECT), respiratory lung motion and cyclically varying changes in lung volume during image acquisition inherently degrade the image sharpness of ill-defined perfusion defects. However, because of the lack of an adequate fast imaging technique, perfusion SPECT has never been acquired under breathhold conditions, where...

Journal: :iranian journal of nuclear medicine 0
hojjat mahani radiation application research school, nuclear science and technology research institute, tehran, iran gholamreza raisali radiation application research school, nuclear science and technology research institute, tehran, iran alireza kamali-asl radiation medicine department, shahid beheshti university, tehran, iran mohammad reza ay research center for molecular and cellular imaging, tehran university of medical science, tehran, iran

introduction:it is well-recognized that collimator-detector response (cdr) is the main image blurring factor in spect.  in this research, we compensated the images for cdr in molecular spect by using stir reconstruction framework. methods: to assess resolution recovery capability of the stir, a phantom containing five point sources along with a micro derenzo phantom were investigated. influence...

Jalil Pirayesh Islamian, Mehdi Momennezhad Michael Ljungberg Mohammad Taghi Bahreyni Toossi, Shahrokh Naseri

Introduction Quality control is an important phenomenon in nuclear medicine imaging. A Jaszczak SPECT Phantom provides consistent performance information for any SPECT or PET system. This article describes the simulation of a Jaszczak phantom and creating an executable phantom file for comparing assessment of SPECT cameras using SIMIND Monte Carlo simulation program which is well-established fo...

2014
Maria Lyra Agapi Ploussi Maritina Rouchota Stella Synefia

Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT) evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of det...

Journal: :Annals of nuclear medicine 2002
Yasuyuki Takahashi Kenya Murase Hiroshi Higashino Teruhito Mochizuki Nobutoku Motomura

PURPOSE Attenuation correction with an X-ray CT image is a new method to correct attenuation on SPECT imaging, but the effect of the registration errors between CT and SPECT images is unclear. In this study, we investigated the effects of the registration errors on myocardial SPECT, analyzing data from a phantom and a human volunteer. METHODS Registerion (fusion) of the X-ray CT and SPECT ima...

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...

Journal: :iranian journal of nuclear medicine 2001
mehdi payghambari seyed hassan firouzabadi mina taghizadeh

this study was performed to evaluate the tc-pyp spect role in determination of ami severity and extension. pyp spect imaging was done for 54 patients with ami, who met the who criteria. spect findings were correlated with lvef measurements. the abnormal scan was graded according to the intensity and was compared with the activity of the sternum in the same image. in addition, a segmental myocar...

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