Monte carlo study of the effect of collimator thickness on T-99m source response in single photon emission computed tomography

Islamian, Jalil Pirayesh; Toossi, Mohammad Taghi Bahreyni; Momennezhad, Mehdi; Sadeghi, Ramin; Ljungberg, Michael

doi:10.4103/1450-1147.103419

Cited by 13 publications

(18 citation statements)

References 23 publications

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“…[ 12 ] The Siemens E.CAM gamma camera equipped with two removable SE-LEHR (Siemens Medical Solutions, Erlangen, Germany) collimators was simulated by the simulating medical imaging nuclear detectors (SIMIND, Developed by Professor Michael Ljungberg, sweden) Monte Carlo simulation program version 5.0, which is well established for SPECT imaging. [ 5 13 14 15 ] A 1.5 mm 99m Tc point source (3.7 MBq) and a Jaszczak Deluxe ECT phantom (model ECT/DLX/P) filled with water and 370 MBq activity of 99m Tc were used for the experiment and simulated systems. [ 16 ] The energy resolution, spatial resolution, image contrast, and system sensitivity as a function of the collimator materials were determined according to the established and published quality control tests.…”

Section: Methodsmentioning

confidence: 99%

“…The quality of the images in SPECT is seriously affected by the collimator's structure, properties of the detector, reconstruction algorithms, and also attenuation/scattering of gamma rays in the patient's body and the collimator. [ 5 6 7 8 ] The collimation system is a critical component of a SPECT imaging system. Performance of a collimator was improved by increasing the absorption efficiency of the collimator material.…”

Section: Introductionmentioning

confidence: 99%

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The Effect of Parallel-hole Collimator Material on Image and Functional Parameters in SPECT Imaging: A SIMIND Monte Carlo Study

et al. 2015

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The collimator in single-photon emission computed tomography (SPECT) is a critical component of the imaging system and plays an impressive role in the imaging quality. In this study, the effect of the collimator material on the radioisotopic image and its functional parameters was studied. The simulating medical imaging nuclear detectors (SIMIND) Monte Carlo program was used to simulate a Siemens E.CAM SPECT (Siemens Medical Solutions, Erlangen, Germany) system equipped with a low-energy high-resolution (LEHR) collimator. The simulation and experimental data from the SPECT imaging modality using 99mTc were obtained on a point source and Jaszczak phantom. Seventeen high atomic number materials were considered as LEHR collimator materials. In order to determine the effect of the collimator material on the image and functional parameters, the energy resolution, spatial resolution, contrast, and collimator characteristics parameters such as septal penetration and scatter-to-primary ratio were investigated. Energy spectra profiles, full width at half maximums (FWHMs) (mm) of the point spread function (PSF) curves, system sensitivity, and contrast of cold spheres of the Jaszczak phantom for the simulated and experiment systems have acceptability superimposed. The results of FWHM and energy resolution for the 17 collimators showed that the collimator made of 98% lead and 2% antimony could provide the best FWHM and energy resolution, 7.68 mm and 9.87%, respectively. The LEHR collimator with 98% lead and 2% antimony offers the best resolution and contrast when compared to other high atomic number metals and alloys.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Effect of Parallel-hole Collimator Material on Image and Functional Parameters in SPECT Imaging: A SIMIND Monte Carlo Study

et al. 2015

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“…The collimator in SPECT is a crucial component of the imaging chain that controls the noise, resolution, and sensitivity of the final functional image. [ 1 2 3 4 5 6 7 8 ] Specialized collimators are used for a specific imaging task, for example the fan beam collimator for brain imaging,[ 9 ] cone beam collimator for posterior portion of the thalamus,[ 10 ] slit slat collimator for radionuclide imaging with high-energy gamma ray emission,[ 11 12 ] and parallel-hole collimators that routinely use in SPECT and planar imaging. The pinhole and multi-pinhole collimators used for research, preclinical study, small animal, and focal uptake nuclear medicine imaging.…”

Section: Introductionmentioning

confidence: 99%

Advances in Pinhole and Multi-Pinhole Collimators For Single Photon Emission Computed Tomography Imaging

et al. 2015

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The collimator in single photon emission computed tomography (SPECT), is an important part of the imaging chain. One of the most important collimators that used in research, preclinical study, small animal, and organ imaging is the pinhole collimator. Pinhole collimator can improve the tradeoff between sensitivity and resolution in comparison with conventional parallel-hole collimator and facilities diagnosis. However, a major problem with pinhole collimator is a small field of view (FOV). Multi-pinhole collimator has been investigated in order to increase the sensitivity and FOV with a preserved spatial resolution. The geometry of pinhole and multi-pinhole collimators is a critical factor in the image quality and plays a key role in SPECT imaging. The issue of the material and geometry for pinhole and multi-pinhole collimators have been a controversial and much disputed subject within the field of SPECT imaging. On the other hand, recent developments in collimator optimization have heightened the need for appropriate reconstruction algorithms for pinhole SPECT imaging. Therefore, iterative reconstruction algorithms were introduced to minimize the undesirable effect on image quality. Current researches have focused on geometry and configuration of pinhole and multi-pinhole collimation rather than reconstruction algorithm. The lofthole and multi-lofthole collimator are samples of novel designs. The purpose of this paper is to provide a review on recent researches in the pinhole and multi-pinhole collimators for SPECT imaging.

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“…As the SIMIND simulated SPECT projections are noise-free, for realization the noise was added according to the administered dose. [ 11 ] The phantom is used for routine quality assurance and control, including system spatial resolution, contrast, and uniformity. [ 9 ] The experiment and also the simulated SPECT of the phantom were generated.…”

Section: Methodsmentioning

confidence: 99%

“…The qualities of the produced images were compared in terms of image contrast and spatial resolution. [ 9 10 11 12 ]…”

Section: Methodsmentioning

confidence: 99%

A study on determination of an optimized detector for single photon emission computed tomography

et al. 2016

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The detector is a critical component of the single photon emission computed tomography (SPECT) imaging system for giving accurate information from the exact pattern of radionuclide distribution in the target organ. The SIMIND Monte Carlo program was utilized for the simulation of a Siemen's dual head variable angle SPECT imaging system with a low energy high resolution (LEHR) collimator. The Planar and SPECT scans for a 99mTc point source and a Jaszczak Phantom with the both experiment and simulated systems were prepared and after verification and validation of the simulated system, the similar scans of the phantoms were compared (from the point of view of the images’ quality), namely, the simulated system with the detectors including bismuth germanate (BGO), yttrium aluminum garnet (YAG:Ce), Cerium-doped yttrium aluminum garnet (YAG:Ce), yttrium aluminum perovslite (YAP:Ce), lutetium aluminum garnet (LuAG:Ce), cerium activated lanthanum bromide (LaBr3), cadmium zinc telluride (CZT), and sodium iodide activated with thallium [NaI(Tl)]. The parameters of full width at half maximum (FWHM), energy and special resolution, sensitivity, and also the comparison of images’ quality by the structural similarity (SSIM) algorithm with the Zhou Wang and Rouse/Hemami methods were analyzed. FWHMs for the crystals were calculated at 13.895, 14.321, 14.310, 14.322, 14.184, and 14.312 keV and the related energy resolutions obtained 9.854, 10.229, 10.221, 10.230, 10.131, and 10.223 %, respectively. Finally, SSIM indexes for comparison of the phantom images were calculated at 0.22172, 0.16326, 0.18135, 0.17301, 0.18412, and 0.20433 as compared to NaI(Tl). The results showed that BGO and LuAG: Ce crystals have high sensitivity and resolution, and better image quality as compared to other scintillation crystals.

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Monte carlo study of the effect of collimator thickness on T-99m source response in single photon emission computed tomography

Cited by 13 publications

References 23 publications

The Effect of Parallel-hole Collimator Material on Image and Functional Parameters in SPECT Imaging: A SIMIND Monte Carlo Study

The Effect of Parallel-hole Collimator Material on Image and Functional Parameters in SPECT Imaging: A SIMIND Monte Carlo Study

Advances in Pinhole and Multi-Pinhole Collimators For Single Photon Emission Computed Tomography Imaging

A study on determination of an optimized detector for single photon emission computed tomography

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