Energy Window Optimization Using Triple Energy Window Scatter Correction Method for In-111 SPECT Imaging: A SIMIND Monte Carlo Study
Hicham
Asmi
Department of Physics, LPHE, Modeling and Simulations, Faculty of Science, Mohammed V University, Rabat, Morocco
author
Farida
Bentayeb
Department of Physics, LPHE, Modeling and Simulations, Faculty of Science, Mohammed V University, Rabat, Morocco
author
Youssef
Bouzekraoui
Higher Institute of Health Sciences Settat, University HASSAN, Rabat, Morocco
author
Faustino
Bonutti
Academic Hospital of Udine, Medical Physics Department, Italy
author
text
article
2021
eng
Introduction: Detecting scattered photons in the photo peak window degrades the image contrast and quantitative accuracy of single-photon emission computed tomography (SPECT) imaging. This study aimed to determine optimal main- and sub-energy windows for Triple Energy Window (TEW) in In-111.
Material and Methods: We used the simulating medical imaging nuclear detectors (SIMIND) program to simulate the Siemens SYMBIA gamma camera equipped with a medium energy (ME) collimator. We also used the SIMIND Monte Carlo program to generate theIn-111SPECT projection data of the Jaszczak phantom. The phantom consisting of six spheres with different diameters (9.5, 12.7, 19.1, 15.9, 25.4, and 31.8 mm) was used to evaluate the image contrast. Geometric, scatter, and penetration fraction, point spread functions, and contrast curves were drawn and compared.
Results: The results showed that the 171keVphotopeak compared to the 245keVphotopeak yielded the best results with an ME collimator when the TEW scatter correction method was applied. The reason can be the large amount of scatter and penetration from the photo peak and the collimator for the 245keVphotopeak window.
Conclusion: With the TEW scatter correction method, it is better to use a 171keVphotopeak window because of its better spatial resolution and image contrast.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
300
305
https://ijmp.mums.ac.ir/article_16351_9f2fc9d212891b13fa278241d6bc9d7c.pdf
dx.doi.org/10.22038/ijmp.2020.46778.1735
Evaluation of Correlation between DAP (Dose-Area Product) Values and Cardiologist Dose during Coronary Angiography Using Monte Carlo Simulation
Reza
Fardid
Department of Radiology, Faculty of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
author
Hadi
Rezaei
Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
author
Fatemeh
Mirzadeh
Faculty of paramedical science , Shiraz University of Medical Sciences.
author
Mohammad Amin
Mosleh-Shirazi
Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
author
mehdi
saeedimoghadam
Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
author
Sedigheh
Sina
Radiation Research Center, Shiraz University, Shiraz, Iran
author
somayeh
delavarifar
Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
author
ashkan
salajegheh
Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
author
text
article
2021
eng
Introduction: The present study investigated the correlations between the patient’s dose-area product (DAP) values and cardiologist’s dose using Monte Carlo simulation. During angiography procedures, patients are exposed to the primary beam; however, the cardiologist is irradiated by the scattered radiation arising from the table and the surrounding equipment. Accordingly, the cardiologist’s dose is directly related to the patient’s dose.
Material and Methods: This study investigated 25 cardiac angiography procedures. In each procedure, the DAP readings and the cardiologist dose as measured using an electronic personal dosimeter placed over the apron were recorded. Moreover, the DAP values and dose received by the cardiologist in the chest region were calculated using the Monte Carlo N-Particle extended code. For the validation of the simulated spectrum, dosimetric measurements were made using a Farmer ionization chamber and a phantom.
Results: The data obtained from 18 simulations showed that there was a strong linear relationship (R2=0.71) between the two variables of cardiologist’s dose and patient’s DAP. Likewise, the obtained results of dosimetry conducted on the patients in 25 cardiac angiography procedures revealed that there was a strong relationship (R2=0.78) between the two variables.
Conclusion: The reported correlation rates show the appropriateness of the physician radiation exposure to total patient’s DAP. With respect to the strong correlation coefficient obtained from the simulation method, it is recommended that this method should be verified by dosimetry. The findings of this study showed a linear relationship between the cardiologist’s dose and the total dose of the patient.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
306
313
https://ijmp.mums.ac.ir/article_17047_ba30ddfb853b16b1a149a13cda9ec29b.pdf
dx.doi.org/10.22038/ijmp.2020.46707.1742
A Dosimetric Study of Optimised and Non-Optimised Plans in Intracavitary Brachytherapy (ICBT) Using International Commission on Radiation Units and Measurement (ICRU) 89
NIDHI
MARJARA
Department of Radiation Oncology,Max Superspeciality Hospital , Shalimar Bagh , Delhi
author
ANIL
BANSAL
Department of Radiation Oncology,Max Superspeciality Hospital , Saket , Delhi
author
DEEPAK
TRIPATHI
Amity Institute of Applied Sciences, Amity University, Noida
author
text
article
2021
eng
Introduction: The study aimed to assess the effectiveness of the dosimetric parameters of organs-at-risks (OARs) and target coverage in optimized plans compared to non-optimised plans normalized at point A.
Material and Methods:This retrospective study examined 21 patients with cervical cancer in stages II and III, who had undergone a high dose rate (HDR) ICBT following external beam radiotherapy(EBRT).In this study, two treatment plans were created for each case using computed tomography (CT) images. Normalization at point A was performed in the non-optimised plans, and 90% of the high-risk clinical target volume (HR-CTV) was to receive the prescribed dose in the optimised plans. Dose-volume histograms (DVH) were used to compare D5cc, D2cc, D1cc, and D0.1cc (minimum doses received by the most irradiated volumes of5cc, 2cc, 1cc and 0.1cc, respectively) for OARs as well as the D90%, D50%, D98%, D100%, and D95% coverage of HR-CTV between the non-optimised and optimised plans. Statistical analysis was performed using Wilcoxon signed rank test.
Results: The HR-CTV coverage improved in 80% of the patients. In the optimised plans, the rectum and bladder doses decreased by 8.75% and 9.85%, as compared to the non-optimised plans normalized at point A, respectively. In the sigmoid and bowel cases, there were dose drops by 8.95% and 9.75%, in the optimised plans, respectively.
Conclusion: Target coverage and OAR sparing were more satisfactory in the optimised plans than the non-optimised plans normalized at point A.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
314
320
https://ijmp.mums.ac.ir/article_16832_5534bbf10322d1bbd388dbf18767180b.pdf
dx.doi.org/10.22038/ijmp.2020.47653.1764
Dosimetric Comparison of Two Linear Accelerator-Based Radiosurgery Systems for Intracranial Tumours with Rapidarc and Dynamic Conformal Arc Therapy
Vaibhav
Mhatre
Department of Radiation Oncology and Neurosurgery, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Andheri, Mumbai, India.
author
Pranav
Chadha
Department of Radiation Oncology and Neurosurgery, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Andheri, Mumbai, India.
author
Rajkumar
Chauhan
Department of Radiation Oncology and Neurosurgery, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Andheri, Mumbai, India.
author
Kaustav
Talapatra
Department of Radiation Oncology and Neurosurgery, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Andheri, Mumbai, India.
author
Abhaya
Kumar
Department of Radiation Oncology and Neurosurgery, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Andheri, Mumbai, India.
author
text
article
2021
eng
Introduction: The present study focused on the dosimetric evaluation of Edge and Novalis Tx (NTx) linear accelerator (LA)-based radiosurgery system by using RapidArc (RA) and dynamic conformal arc (DCA) planning techniques.
Material and Methods: Forty patients with brain lesions of variable sizes (1.1-15.98 cc) were planned for Edge and NTx system by using the RA and DCA planning techniques on eclipse treatment planning system, version 13.6 (Varian Medical Systems, Palo Alto, CA, USA). All the plans were evaluated on the basis of paddick conformity index (PCI), homogeneity index (HI), and gradient index (GI). The maximum doses to organs at risk (OAR), V12Gy, V10Gy, and V5Gy for healthy brain tissue were also evaluated for all the plans. The treatment delivery efficiency for both systems was also evaluated.
Results: The mean PCI and GI for both RA and DCA plans were found to be better in Edge as compared to NTx system (PCI Edge, RA=0.77±0.1, PCI NTx, RA=0.66±0.11, PCI Edge, DCA= 0.69±0.12, PCI NTx,DCA= 0.67±0.12). Significant differences in HI, doses to OAR, and V12Gy, V10Gy, and V5Gy brain volume were observed for both systems with p-value less than 0.05. Reduced treatment time was observed in Edge LA as compared to NTx LA.
Conclusion: Edge LA produced clinically better target volume conformity, rapid dose fall-off, and reduced reduction in normal brain volume irradiation and treatment time compared to NTx. Thus, in the set of patient plans evaluated, it was noted that Edge stereotactic suite is more efficacious and diametrically suitable for intracranial radiosurgery.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
321
330
https://ijmp.mums.ac.ir/article_16338_fb3204ae8e9a620b3377614ccf92b883.pdf
dx.doi.org/10.22038/ijmp.2020.48162.1775
Dosimetric Study in Tomotherapy Based on AAPM TG 119 Structures: A Longitudinal Moving Phantom Case
Nuruddin
Nasution
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, West Java, 16424, Indonesia
Department of Radiotherapy, Cipto Mangunkusumo General Hospital, Jakarta, 10430, Indonesia
author
Wahyu
Wibowo
Department of Radiotherapy, Cipto Mangunkusumo General Hospital, Jakarta, 10430, Indonesia
author
Adi Teguh
Purnomo
Transmedik Indonesia, Jakarta, 10410, Indonesia
author
Supriyanto
Pawiro
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, West Java, 16424, Indonesia
author
text
article
2021
eng
Introduction: Tomotherapy beam delivery is in the helical form. Therefore, the dose distribution will be more complex while target is moving. In this study, we sought to evaluate the dosimetric impact due to longitudinal motion in the phantom of a tomotherapy machine. Material and Methods: Cheese and Delta4 phantom+ were placed on a respiratory motion platform. They moved in longitudinal directions at the amplitudes of 2, 4, 6, 8, and 10 mm. The period of that movement was 4 and 6 s with the field widths of 25 and 50 mm, respectively. The C-shaped complex target was modified according to the American Association of Physicists in Medicine (AAPM) Task Group (TG) 119. The planning verifications were evaluated through point dose, gamma index value, and dose-volume histogram (DVH).Results: Discrepancy of the dose measurements ranged from -1.254 to -14.421%. The range of gamma index value was 61.2 ±1.23% to 100±0.00. The DVH evaluation showed that the homogeneity index (HI) and the minimum dose to receive by 95% (D95%) of the target structure were 0.247 to 0.389 and -0.061 to -0.271 Gy, respectively. The maximum dose (DMax) of the organ at risk (OAR) structure was 0.082 to 0.327 Gy.Conclusion: The motion could induce dose discrepancies in tomotherapy dose distribution. The selection of the jaw field width in tomotherapy is crucial for intensity-modulated radiotherapy (IMRT) techniques with moving targets. For larger field widths, the dose discrepancy between the planned and measured doses exhibited an excellent result for gamma index and dose coverage.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
331
338
https://ijmp.mums.ac.ir/article_16343_d89d449ee6581bf386488501897aa08e.pdf
dx.doi.org/10.22038/ijmp.2020.47698.1762
Simultaneous Diffusion and T1 Weighted Contrast Imaging for Human Brain Mapping
Marzieh
Nezamzadeh
Department of Radiology and Biomedical Imaging, University of California, San Francisco, USA
Medical Science School, Tarbiat Modares University, Tehran, Iran
author
Norbert
Schuff
Department of Radiology and Biomedical Imaging, University of California, San Francisco, USA
author
text
article
2021
eng
Introduction: Diffusion tensor imaging (DTI) is typically obtained by echo-planar imaging (EPI) to map the human brain. However, EPI is sensitive to susceptibility effects, requiring elaborate image post-processing. Besides, DTI alone is limited in assessing gray and white matter boundaries of the brain, which has important implications for obtaining accurate images from brain atrophy. This study aimed to design and evaluate simultaneous diffusion and T1 weighting high-resolution imaging for human brain mapping.
Material and Methods: The method of T1 weighted three-dimensional Magnetization-prepared rapid gradient-echo (T1w 3D MPRAGE), which is conventionally used for structural brain mapping of gray and white matter, was extended to incorporate diffusion encoding using simulation and experiment to develop high-resolution DTI and T1-weighted human brain data.
Results: Theoretical simulations, as well as experimental results from in-vivo human brain studies at 4 Tesla magnetic field strength, showed that the DTI contrast, including fractional anisotropy (FA) and mean diffusivity (MD), incorporated into T1w 3D MPRAGE improves the contrast between gray and white matter sub-structural boundaries. Moreover, diffusion encoding into 3D MPRAGE avoids the inherent image distortions typically seen in EPI-based DTI.
Conclusion: This study suggests the capability and effectiveness of the combined DTI weighted 3D MPRAGE and T1 weighted for improving the detection of gray/white matter boundaries in human brain imaging.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
339
345
https://ijmp.mums.ac.ir/article_16414_aee34ba4952edb870bf37eda04b21de1.pdf
dx.doi.org/10.22038/ijmp.2020.49358.1795
A comparison of treatment duration for Cobalt-60 and Iridium-192 sources with different activities in HDR brachytherapy using tandem-ovoid applicator
Mohammad Hosein
Sadeghi
School of Mechanical Engineering, Shiraz University, Shiraz, Iran
author
Sedigheh
Sina
Radiation Research Center, Shiraz University, Shiraz, Iran
author
Ali
Meigooni
Comprehensive cancer center of Nevada, Las Vegas, USA
author
text
article
2021
eng
Introduction: The long-half-life Cobalt-60 source with high dose rate (HDR) brachytherapy is an appropriate alternative to Iridium-192 (HDR) source in the treatment of GYN patients in developing countries. This study aimed to compare HDR cervical cancer treatment duration using Cobalt-60 and Iridium-192 sources for the Tandem-ovoid applicators.
Material and Methods: In the present study, BEBIG Cobalt-60 source model Co0.A86 and Iridium-192 source model mHDR-v2r were utilized. The treatment time required for both radionuclides was calculated using the TG-43 formalism. To calculate the treatment time for the Iridium source, the absorbed dose was used in the TG-43 formalism and treatment data. Then the dwell times were determined after repeating the calculations with Cobalt-60. Finally, the comparison was made for the treatment duration for the two sources.
Results: According to our findings, the treatment time for the cobalt source with the activity of 2.131 Ci is somehow the same as that of the iridium source with the activity of 5.690 Ci. If the maximum treatment duration is supposed to be 16 minutes in a treatment session, the effective time window for Iridium-192 is about 160 days. This is, however, the effective time window is 2000 days for Cobalt-60.
Conclusion: According to the findings, the use of Cobalt-60 instead of Iridium-192 is economically beneficial for equipment selection in newly constructed departments. Changes in the activities of Cobalt-60 in comparison with Iridium-192 requires editing the total treatment time of the treatment planning system for patients. Such editing may raise errors and reduce accuracy.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
346
351
https://ijmp.mums.ac.ir/article_16266_a075eee82cd4fe6fa3b2755d45687576.pdf
dx.doi.org/10.22038/ijmp.2020.45759.1717
Assessment of Internal and External Surrogates for Lung Stereotactic Body Radiation Therapy
MILOVAN
SAVANOVIC
Faculty of Medicine, University of Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
Department of Radiation Oncology, Tenon Hospital, 75020 Paris, France.
author
Bojan
Strbac
MATER Private Hospital, Physics department, Eccles Street, Dublin 7, Ireland.
author
Drazan
Jaros
Affidea, International Medical Centers, Center for Radiotherapy, 78000 Banja Luka, Bosnia and Herzegovina.
author
Dejan
Cazic
Affidea, International Medical Centers, Center for Radiotherapy, 78000 Banja Luka, Bosnia and Herzegovina.
author
Goran
Kolarevic
Affidea, International Medical Centers, Center for Radiotherapy, 78000 Banja Luka, Bosnia and Herzegovina.
author
Jean-Noel
Foulquier
Faculty of Medicine, University of Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
author
text
article
2021
eng
Introduction: In this study, we aimed to evaluate internal (lung, heart and diaphragm) and external (nine glass marbles) marker motion in correlation with lung tumor motion and determine potential surrogate for respiratory gating radiation therapy (RGRT) depending on tumor localization, upper lobe (UL) versus lower lobe (LL).Material and Methods: We included 58 patients (34 male and 24 female) with small lung cancer (≤ 5cm), who underwent stereotactic body radiation therapy (SBRT). All patients were scanned and contoured in all ten phases (Varian Eclipse 13.7) after four-dimensional computed tomography simulation (4D-CT). The motions of internal and external markers were analyzed and correlated with tumor motion. Pearson correlation coefficient (PCC) was used to evaluate the correlation between internal and external marker motion and tumor motion.Results: The median (range) values of tumor motion were 3.2 (0.6-11.0) and 8.6 (4.0-24.0) mm in the UL and LL, respectively. The median (range) values of organs motion and PCC comparing UL vs. LL were 2.0 (0.3-9.1) vs. 6.0 (2.8-13.9) mm and 0.46 (0.30-0.95) vs. 0.79 (0.50-0.94) for the lung, respectively, 11.9 (2.5-16.3) vs. 12.5 (5.0-22.5) mm and 0.68 (0.11-0.93) vs. 0.89 (0.30-0.99) for the diaphragm, respectively, and 3.9 (2.5-6.3) vs. 7.6 (4.5-8.6) mm and 0.49 (0.20-0.70) vs. 0.59 (0.36-0.83) for the heart, respectively. The external marker motion and correlation coefficient for UL and LL were 2.5 (0.9-7.4) vs. 2.3 (1.0-5.9) mm and 0.54 (0.09-0.96) vs. 0.73 (0.27-0.94), respectively.Conclusion: Lung and diaphragm motion correlate better with tumor motion than the external marker. Diaphragm motion can be an excellent indicator for treatment based on RGRT.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
352
360
https://ijmp.mums.ac.ir/article_16369_fbf5950c7c237febf89bed6a914361f4.pdf
dx.doi.org/10.22038/ijmp.2020.50131.1820
An In-Vitro Study on Photochemical Internalization of Methylene Blue with Gold Nanoparticles Coated By Thio-Glucose
Maryam
Shabanzadeh
Department of Medical Radiation, Faculty of Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran.
author
Alireza
Shirazi
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
author
Armin
Imanparast
Medical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
author
zahra
mohammadi
Medical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
author
Ameneh
Sazgarnia
Medical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
author
text
article
2021
eng
Introduction: Photochemical internalization is a novel PDT-based technology for the intracellular delivery of hydrophilic macromolecular therapeutic agents and other drugs limited in penetration into cellular membranes with intracellular targets. In this regard, one of the approaches is to use nanoparticles along with photosensitizing agents. In this study, the presence of thioglucose-coated gold nanoparticles in the efficiency of the photodynamic effect of methylene blue (MB) caused by the photochemical internalization phenomenon was investigated.
Material and Methods: First, Glu-GNPs was synthesized, and then the toxicity of Glu-GNPs and MB were determined to achieve their optimal concentrations. Afterward, the photodynamic effects of Glu-GNPs combined with MB by Luma-Care source light were evaluated at different doses using MTT assay and colony assay (12 days after treatment).
Results: According to the MTT assay, the photodynamic effect in the Glu-GNPs group revealed no significant efficacy, whereas the colony-formation capability in all groups with an optical dose of 15.6 J / cm2 decreased, compared to the similar group without light exposure (P < 0.05).
Conclusion: The photodynamic efficiency of MB with the Glu-GNPs group was reduced at 15.6 J/cm2, compared to the free MB group. The decreased efficiency can have various reasons such as the photochemical bleaching of the free MB because of ROS and 1O2 produced by the plasmonic photodynamic phenomenon of Glu-GNPs or changing the optophysical properties of surface plasmon resonance of final product (MB+ Glu-GNPs) due to the possible electrostatic bonding of the drug with the nanoparticles.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
361
368
https://ijmp.mums.ac.ir/article_16846_29ee581a739867826740a45cb78e28af.pdf
dx.doi.org/10.22038/ijmp.2020.39283.1518
An Assessment on Implementation of Imperialist Competitive Algorithm for Motion Dataset Optimization at Radiotherapy with External Surrogates
Ahmad
Esmaili Torshabi
Faculty of Sciences and Modern Technologies, Graduate University of Advanced Technology, Kerman, Iran.
author
Moslem
Ahmadi Arbatan
Faculty of Sciences and Modern Technologies, Graduate University of Advanced Technology, Kerman, Iran.
author
text
article
2021
eng
Introduction: One of the most important components in radiotherapy with external surrogates is utilizing consistent correlation model to estimate tumor location as model output on the basis of external markers motion dataset. In this study, imperialist competitive algorithm (ICA) was proposed to process and optimize motion dataset for correlation model. The simplicity of correlation model based on this algorithm may result in less targeting error with the least computational time.
Material and Methods: A correlation model based on adaptive neuro-fuzzy inference system (ANFIS) was utilized with database of 20 patients treated with CyberKnife Synchrony system. In order to assess the effect of proposed data optimization algorithm, two strategies were considered. The correlation model was used with and without implementing ICA. Then, targeting error of ANFIS model was compared at two strategies using statistical analysis.
Results: The results showed that implementing the proposed algorithm on ANFIS model could remarkably improve the performance accuracy of ANFIS correlation model by eliminating unnecessary and noisy inputs and making the model simpler. Moreover, model simplicity factor could highly reduce model computational time, which is attractive for clinical practice.
Conclusion: ICA was proposed as data optimization algorithm on motion dataset of patients treated with external surrogates’ radiotherapy. Our proposed algorithm could highly optimize the input motion dataset of correlation model for estimating tumor position by selecting enough data points with high degree of importance. The final results showed an improvement of targeting accuracy of correlation model, as well as a significant reduction at model computational time.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
369
375
https://ijmp.mums.ac.ir/article_16759_0af0f9511c66ceed6284b1a3ae3d9d14.pdf
dx.doi.org/10.22038/ijmp.2020.47283.1752
Investigation of Noise Level and Spatial Resolution of CT Images Filtered with a Selective Mean Filter and Its Comparison to an Adaptive Statistical Iterative Reconstruction
Ummu
Zahro
Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia
author
Choirul
Anam
Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia
author
Wahyu
Budi
Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia
author
Pandji
Triadyaksa
Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia
author
Jhon
Saragih
Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia
author
Dito
Rukmana
Department of Radiology, Indriati Hospital Solo Baru, Jl. Palem Raya, Dusun III, Sukoharjo 57552, Central Java, Indonesia
author
text
article
2021
eng
Introduction: A simple noise reduction algorithm, i.e. a selective mean filter (SMF), had been previously introduced. The aim of this study is to investigate the image qualities filtered by a SMF and its comparison to an adaptive statistical iterative reconstruction (ASIR).
Material and Methods: To assess the basic image quality, an American Association of Physicists in Medicine Computed Tomography (AAPM CT) performance phantom was used. The phantom was scanned by 128 Multiple Slices Computed Tomography. The tube current varied from 50 mA to 100, 150, and 200 mA. The images of a phantom were reconstructed by filtered back projection (FBP) followed by SMF and ASIR (20, 40, 60, 80, and 100%). The image quality assessment was in terms of noise level, noise power spectrum (NPS), and modulation transfer function (MTF).
Results: The noise level and NPS of SMF was similar with ASIR 100%. The values of the MTF10 of the ASIR filter at any level and SMF were comparable. The MTF10 values of ASIR 60%, and SMF with 50 mA (low) were 0.76 ± 0.02 and 0.75 ± 0.02 cycle/mm, respectively. Meanwhile, the MTF10 of ASIR 60% and SMF with 200 mA (high) were 0.74 ± 0.00 and 0.73 ± 0.00 cycles/mm, respectively.
Conclusion: Our results indicated that the performance of the SMF in reducing noise is equivalent to the maximum level of ASIR strength, i.e., ASIR 100%.
Iranian Journal of Medical Physics
Mashhad University of Medical Sciences
2345-3672
18
v.
5
no.
2021
376
383
https://ijmp.mums.ac.ir/article_16265_3f239a401b02b755b096b3b9e8a50729.pdf
dx.doi.org/10.22038/ijmp.2020.48813.1786