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Article ; Online: Detection of stage of lung changes in COVID-19 disease based on CT images: a radiomics approach.

Mehrpouyan, Mohammad / Zamanian, Hamed / Mehri-Kakavand, Ghazal / Pursamimi, Mohamad / Shalbaf, Ahmad / Ghorbani, Mahdi / Abbaskhani Davanloo, Amirhossein

Physical and engineering sciences in medicine

2022 Volume 45, Issue 3, Page(s) 747–755

Abstract: The aim of this study is to classify patients suspected from COVID-19 to five stages as normal, early, progressive, peak, and absorption stages using radiomics approach based on lung computed tomography images. Lung CT scans of 683 people were evaluated. ...

Abstract	The aim of this study is to classify patients suspected from COVID-19 to five stages as normal, early, progressive, peak, and absorption stages using radiomics approach based on lung computed tomography images. Lung CT scans of 683 people were evaluated. A set of statistical texture features was extracted from each CT image. The people were classified using the random forest algorithm as an ensemble method based on the decision trees outputs to five stages of COVID-19 disease. Proposed method attains the highest result with an accuracy of 93.55% (96.25% in normal, 74.39% in early, 100% in progressive, 82.19% in peak, and 96% in absorption stage) compared to the other three common classifiers. Radiomics method can be used for the classification of the stage of COVID-19 disease with good accuracy to help decide the length of time required to hospitalize patients, determine the type of treatment process required for patients in each category, and reduce the cost of care and treatment for hospitalized individuals.
MeSH term(s)	COVID-19/diagnostic imaging ; Humans ; Lung/diagnostic imaging ; Lung Neoplasms ; Thorax ; Tomography, X-Ray Computed/methods
Language	English
Publishing date	2022-07-07
Publishing country	Switzerland
Document type	Journal Article
ISSN	2662-4737
ISSN (online)	2662-4737
DOI	10.1007/s13246-022-01140-4
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources

Ghorbani Mahdi / Mehrpouyan Mohammad / Davenport David / Ahmadi Moghaddas Toktam

Radiology and Oncology, Vol 50, Iss 2, Pp 238-

2016 Volume 246

Abstract: The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. ...

Abstract	The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters.
Keywords	photon energy spectrum ; brachytherapy ; tg-43 dosimetric parameters ; dose distribution ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Language	English
Publishing date	2016-06-01T00:00:00Z
Publisher	Sciendo
Document type	Article ; Online
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Article: Feasibility of Treatment Planning System in Localizing the COVID-19 Pneumonia Lesions and Evaluation of Volume Indices of Lung Involvement.

Ghahramani-Asl, Ruhollah / Porouhan, Pejman / Mehrpouyan, Mohammad / Welsh, James S / Calabrese, Edward J / Kapoor, Rachna / Dhawan, Gaurav / Javadinia, Seyed Alireza

Dose-response : a publication of International Hormesis Society

2020 Volume 18, Issue 3, Page(s) 1559325820962600

Abstract: Background and purpose: To assess the feasibility of a treatment planning system in localizing, contouring, and targeting lung lesions along with an evaluation of volume indices of lung involvement in patients with COVID-19 pneumonia.: Methods: We ... ...

Abstract	Background and purpose: To assess the feasibility of a treatment planning system in localizing, contouring, and targeting lung lesions along with an evaluation of volume indices of lung involvement in patients with COVID-19 pneumonia. Methods: We evaluated 10 patients with PCR-confirmed COVID-19 pneumonia. The CT images were imported into the ISOgray® treatment planning system to anatomically define and contour the volumes of the pulmonary lesions, the lungs, and other nearby organs. Results: The ratio of lung lesion volume to lung volume in this study was 0.11 ± 0.13 (11.13%). The highest mean biosynthesis ratio of lung lesions was 0.36. The ratio of lesion volume in the left lung of patients with the highest volume of involvement, was 0.44, and the ratio of lesion volume in the right lung of these patients was 0.27 (approximately 1.5 times more in the left lung than the right lung). On average, CTDIvol and DLP for all patients studied in our study were 11.22 ± 2.47 mGy and 354.20 ± 65.11 mGy.cm. Conclusion: We reported the feasibility of using a treatment planning system in localizing COVID-19 pulmonary lesions and its validity in the volumetric assessment of infected lung regions.
Keywords	covid19
Language	English
Publishing date	2020-09-29
Publishing country	United States
Document type	Journal Article
ZDB-ID	2440820-7
ISSN	1559-3258
ISSN	1559-3258
DOI	10.1177/1559325820962600
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Article ; Online: Determination of dosimetric parameters for shielded 153Gd source in prostate cancer brachytherapy

Ghorbani Mahdi / Khajetash Benyamin / Ghatei Najmeh / Mehrpouyan Mohammad / Meigooni Ali S. / Shahraini Ramin

Radiology and Oncology, Vol 51, Iss 1, Pp 101-

2017 Volume 112

Abstract: Interstitial rotating shield brachytherapy (I-RSBT) is a recently developed method for treatment of prostate cancer. In the present study TG-43 dosimetric parameters of a 153Gd source were obtained for use in I-RSBT. ...

Abstract	Interstitial rotating shield brachytherapy (I-RSBT) is a recently developed method for treatment of prostate cancer. In the present study TG-43 dosimetric parameters of a 153Gd source were obtained for use in I-RSBT.
Keywords	interstitial rotating shield brachytherapy ; 153gd ; tg-43 dosimetric parameters ; monte carlo simulation ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
Language	English
Publishing date	2017-02-01T00:00:00Z
Publisher	Sciendo
Document type	Article ; Online
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Article: Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources.

Ghorbani, Mahdi / Mehrpouyan, Mohammad / Davenport, David / Ahmadi Moghaddas, Toktam

Radiology and oncology

2016 Volume 50, Issue 2, Page(s) 238–246

Abstract: Aim: The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters.: Background: Different photon spectra are used for a specific radionuclide in Monte ... ...

Abstract	Aim: The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. Background: Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources. Materials and methods: MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources. Air kerma strength per activity, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated and isodose curves were plotted for three different photon energy spectra. The references for photon energy spectra were: published papers, Lawrence Berkeley National Laboratory (LBNL), and National Nuclear Data Center (NNDC). The data calculated by these photon energy spectra were compared. Results: Dose rate constant values showed a maximum difference of 24.07% for 103Pd source with different photon energy spectra. Radial dose function values based on different spectra were relatively the same. 2D anisotropy function values showed minor differences in most of distances and angles. There was not any detectable difference between the isodose contours. Conclusions: Dosimetric parameters obtained with different photon spectra were relatively the same, however it is suggested that more accurate and updated photon energy spectra be used in Monte Carlo simulations. This would allow for calculation of reliable dosimetric data for source modeling and calculation in brachytherapy treatment planning systems.
Language	English
Publishing date	2016-03-31
Publishing country	Poland
Document type	Journal Article
ZDB-ID	1128829-2
ISSN	1318-2099 ; 0485-893X
ISSN	1318-2099 ; 0485-893X
DOI	10.1515/raon-2016-0019
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Article: Determination of dosimetric parameters for shielded

Ghorbani, Mahdi / Khajetash, Benyamin / Ghatei, Najmeh / Mehrpouyan, Mohammad / Meigooni, Ali S / Shahraini, Ramin

Radiology and oncology

2017 Volume 51, Issue 1, Page(s) 101–112

Abstract: Background: Interstitial rotating shield brachytherapy (I-RSBT) is a recently developed method for treatment of prostate cancer. In the present study TG-43 dosimetric parameters of a : Materials and methods: A : Results: The air kerma strength was ...

Abstract	Background: Interstitial rotating shield brachytherapy (I-RSBT) is a recently developed method for treatment of prostate cancer. In the present study TG-43 dosimetric parameters of a Materials and methods: A Results: The air kerma strength was found to be 6.71 U for the non-shielded source with 1 GBq activity. This value was found to be 0.04 U and 6.19 U for the Pt shield and Al window cases, respectively. Dose rate constant for the non-shielded source was found to be 1.20 cGy/(hU). However, for a shielded source with Pt and aluminum window, dose rate constants were found to be 0.07 cGy/(hU) and 0.96 cGy/(hU), on the shielded and window sides, respectively. The values of radial dose function and anisotropy function were tabulated for these sources. Additionally, isodose curves were drawn for sources with and without shield, in order to evaluate the effect of shield on dose distribution. Conclusions: Existence of the Pt shield may greatly reduce the dose to organs at risk and normal tissues which are located toward the shielded side. The calculated air kerma strength, dose rate constant, radial dose function and 2D anisotropy function data for the
Language	English
Publishing date	2017-02-22
Publishing country	Poland
Document type	Journal Article
ZDB-ID	1128829-2
ISSN	1318-2099 ; 0485-893X
ISSN	1318-2099 ; 0485-893X
DOI	10.1515/raon-2017-0009
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Article ; Online: Preliminary results of an attempt to predict over apron occupational exposure of cardiologists from cardiac fluoroscopy procedures based on DAP (dose area product) values.

Toossi, Mohammad Taghi Bahreyni / Mehrpouyan, Mohammad / Nademi, Hossein / Fardid, Reza

Australasian physical & engineering sciences in medicine

2015 Volume 38, Issue 1, Page(s) 83–91

Abstract: This study is an effort to propose a mathematical relation between the occupational exposure measured by a dosimeter worn on a lead apron in the chest region of a cardiologist and the dose area product (DAP) recorded by a meter attached to the X-ray tube. ...

Abstract	This study is an effort to propose a mathematical relation between the occupational exposure measured by a dosimeter worn on a lead apron in the chest region of a cardiologist and the dose area product (DAP) recorded by a meter attached to the X-ray tube. We aimed to determine factors by which DAP values attributed to patient exposure could be converted to the over-apron entrance surface air kerma incurred by cardiologists during an angiographic procedure. A Rando phantom representing a patient was exposed by an X-ray tube from 77 pre-defined directions. DAP value for each exposure angle was recorded. Cardiologist exposure was measured by a Radcal ionization chamber 10X5-180 positioned on a second phantom representing the physician. The exposure conversion factor was determined as the quotient of over apron exposure by DAP value. To verify the validity of this method, the over-apron exposure of a cardiologist was measured using the ionization chamber while performing coronary angiography procedures on 45 patients weighing on average 75 ± 5 kg. DAP values for the corresponding procedures were also obtained. Conversion factors obtained from phantom exposure were applied to the patient DAP values to calculate physician exposure. Mathematical analysis of our results leads us to conclude that a linear relationship exists between two sets of data: (a) cardiologist exposure measured directly by Radcal & DAP values recorded by the X-ray machine system (R (2) = 0.88), (b) specialist measured and estimated exposure derived from DAP values (R (2) = 0.91). The results demonstrate that cardiologist occupational exposure can be derived from patient data accurately.
MeSH term(s)	Coronary Angiography ; Fluoroscopy/statistics & numerical data ; Humans ; Male ; Models, Theoretical ; Occupational Exposure/analysis ; Radiation Exposure/analysis ; Radiation Protection
Language	English
Publishing date	2015-03
Publishing country	Netherlands
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	46226-3
ISSN	1879-5447 ; 0158-9938
ISSN (online)	1879-5447
ISSN	0158-9938
DOI	10.1007/s13246-014-0326-1
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Article ; Online: A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

Toossi Mohammad Taghi Bahreyni / Ghorbani Mahdi / Sabet Leila Sobhkhiz / Akbari Fateme / Mehrpouyan Mohammad

Nukleonika, Vol 60, Iss 3, Pp 489-

2015 Volume 496

Abstract: The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a ...

Abstract	The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefit in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams.
Keywords	dose enhancement ; electron mode ; monte carlo ; nanoparticles ; photon contamination ; Science ; Q
Language	English
Publishing date	2015-07-01T00:00:00Z
Publisher	Sciendo
Document type	Article ; Online
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Article ; Online: Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

Bahreyni Toossi, Mohammad Taghi / Ghorbani, Mahdi / Akbari, Fatemeh / Mehrpouyan, Mohammad / Sobhkhiz Sabet, Leila

Australasian physical & engineering sciences in medicine

2016 Volume 39, Issue 1, Page(s) 113–122

Abstract: The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron ... ...

Abstract	The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.
MeSH term(s)	Dental Restoration, Permanent ; Electrons ; Monte Carlo Method ; Phantoms, Imaging ; Photons ; Radiotherapy Dosage ; Tooth/radiation effects
Language	English
Publishing date	2016-03
Publishing country	Netherlands
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	46226-3
ISSN	1879-5447 ; 0158-9938
ISSN (online)	1879-5447
ISSN	0158-9938
DOI	10.1007/s13246-015-0404-z
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Article ; Online: Feasibility of Treatment Planning System in Localizing the COVID-19 Pneumonia Lesions and Evaluation of Volume Indices of Lung Involvement

Ghahramani-Asl, Ruhollah / Porouhan, Pejman / Mehrpouyan, Mohammad / Welsh, James S. / Calabrese, Edward J. / Kapoor, Rachna / Dhawan, Gaurav / Javadinia, Seyed Alireza

Dose-Response

2020 Volume 18, Issue 3, Page(s) 155932582096260

Abstract	Background and purpose: To assess the feasibility of a treatment planning system in localizing, contouring, and targeting lung lesions along with an evaluation of volume indices of lung involvement in patients with COVID-19 pneumonia. Methods: We evaluated 10 patients with PCR-confirmed COVID-19 pneumonia. The CT images were imported into the ISOgray® treatment planning system to anatomically define and contour the volumes of the pulmonary lesions, the lungs, and other nearby organs. Results: The ratio of lung lesion volume to lung volume in this study was 0.11 ± 0.13 (11.13%). The highest mean biosynthesis ratio of lung lesions was 0.36. The ratio of lesion volume in the left lung of patients with the highest volume of involvement, was 0.44, and the ratio of lesion volume in the right lung of these patients was 0.27 (approximately 1.5 times more in the left lung than the right lung). On average, CTDIvol and DLP for all patients studied in our study were 11.22 ± 2.47 mGy and 354.20 ± 65.11 mGy.cm Conclusion: We reported the feasibility of using a treatment planning system in localizing COVID-19 pulmonary lesions and its validity in the volumetric assessment of infected lung regions.
Keywords	Toxicology ; Public Health, Environmental and Occupational Health ; Health, Toxicology and Mutagenesis ; Chemical Health and Safety ; covid19
Language	English
Publisher	SAGE Publications
Publishing country	us
Document type	Article ; Online
ZDB-ID	2440820-7
ISSN	1559-3258 ; 1559-3258
ISSN (online)	1559-3258
ISSN	1559-3258
DOI	10.1177/1559325820962600
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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