image optimization in single photon emission computed tomography by hardware modifications with monte carlo simulation

Authors

mohammad taghi bahreyni toossi professor, medical physics research center, faculty of medicine, mashhad university of medical sciences, mashhad, iran

jalil pirayesh islamian assistant professor, medical physics dept., faculty of medicine, tabriz university of medical sciences, tabriz, iran

mahdi momennezhad assistant professor, nuclear medicine dept., imam reza hospital, mashhad university of medical sciences, mashhad, iran

seyed rasoul zakavi associate professor, nuclear medicine dept., imam reza hospital, mashhad university of medical sciences, mashhad, iran

abstract

introduction: in single photon emission computed tomography (spect), the projection data used for image reconstruction are distorted by several factors, including attenuation and scattering of gamma rays, collimator structure, data acquisition method, organ motion, and washout of radiopharmaceuticals. all these make reconstruction of a quantitative spect image very difficult. simulation of a spect system is a convenient method to assess the impact of these factors on the image quality. materials and methods: the simind monte carlo program was employed to simulate a siemens e.cam spect system. verification of the simulation was performed by comparing the performance parameters of the system. the verified system was used for spect simulations of homogenous and inhomogeneous voxelized phantoms in conjugation with hardware modifications. the resulting data were compared with those obtained from the simulated system without any modifications. image quality was assessed by comparing the structural simularity index (ssim), contrast, and resolution of images. results: the energy spectra acquired from both simulated and real spect systems demonstrated similar energy peak regions. the resulting full-widths-at-half-maximums were 13.92 kev for the simulation and 13.58 kev for experimental data, corresponding to energy resolutions of 9.95% and 9.61%, and with calculated sensitivities of 85.39 and 85.11 cps/mbq, respectively. better performance parameters were obtained with a hardware-modified system constructed using a 0.944 cm thickness nai(tl) crystal covered by a layer of 0.24 cm aluminum, a  slat of 4.5 cm pyrex as a backscattering medium, and a parallel hole collimator of pb-sb alloy with 2.405 cm thickness. conclusion: the modeling of a siemens e.cam spect system was performed with the simind monte carlo code. results obtained with the code are in good agreement with experimental results. the findings demonstrate that the proposed hardware modifications in the system appear to be suitable for further improvement of the performance parameters of the system, indicating that future investigations can be conducted on using the system for supplementary studies on image improvement in the field of nuclear medicine.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

Image Optimization in Single Photon Emission Computed Tomography by Hardware Modifications with Monte Carlo Simulation

Introduction: In Single Photon Emission Computed Tomography (SPECT), the projection data used for image reconstruction are distorted by several factors, including attenuation and scattering of gamma rays, collimator structure, data acquisition method, organ motion, and washout of radiopharmaceuticals. All these make reconstruction of a quantitative SPECT image very difficult. Simulation of a SP...

full text

Monte Carlo Study of the Effect of Backscatter Materail Thickness on 99mTc Source Response in Single Photon Emission Computed Tomography

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...

full text

Determination of the Energy Windows for the Triple Energy Window Scatter Correction Method in Gadolinium-159 Single Photon Emission Computed Tomography Using Monte Carlo Simulation

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...

full text

monte carlo study of the effect of backscatter materail thickness on 99mtc source response in single photon emission computed tomography

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...

full text

The Use of Monte Carlo Simulation in Improving Recon- Struction Quality in Single Photon Emission Computed Tomography

This paper describes an efficient method of generating a model-based system matrix using Monte Carlo simulation for incorporation into reconstruction algorithms for pinhole SPECT imaging and reconstructions. The method is able to model the imaging geometry for pinhole collimators and the detector depth of interaction effect accurately and efficiently, and has demonstrated improvement in the qua...

full text

My Resources

Save resource for easier access later


Journal title:
iranian journal of medical physics

جلد ۷، شماره ۲، صفحات ۹-۲۰

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023