Pub Date : 2016-04-06DOI: 10.18178/wcse.2016.06.082
Shipeng Xie, Rui-ju Yan
In Cone-Beam CT (CBCT) imaging systems, the scattering phenomenon has a significant impact on the reconstructed image and is a long-lasting research topic on CBCT. In this paper, we propose a simple, novel and fast approach for mitigating scatter artifacts and increasing the image contrast in CBCT, belonging to the category of convolution-based method in which the projected data is de-convolved with a convolution kernel. A key step in this method is how to determine the convolution kernel. Compared with existing methods, the estimation of convolution kernel is based on bi-l1-l2-norm regularization imposed on both the intermediate the known scatter contaminated projection images and the convolution kernel. Our approach can reduce the scatter artifacts from 12.930 to 2.133.
{"title":"Scattering correction based on regularization de-convolution for Cone-Beam CT","authors":"Shipeng Xie, Rui-ju Yan","doi":"10.18178/wcse.2016.06.082","DOIUrl":"https://doi.org/10.18178/wcse.2016.06.082","url":null,"abstract":"In Cone-Beam CT (CBCT) imaging systems, the scattering phenomenon has a significant impact on the reconstructed image and is a long-lasting research topic on CBCT. In this paper, we propose a simple, novel and fast approach for mitigating scatter artifacts and increasing the image contrast in CBCT, belonging to the category of convolution-based method in which the projected data is de-convolved with a convolution kernel. A key step in this method is how to determine the convolution kernel. Compared with existing methods, the estimation of convolution kernel is based on bi-l1-l2-norm regularization imposed on both the intermediate the known scatter contaminated projection images and the convolution kernel. Our approach can reduce the scatter artifacts from 12.930 to 2.133.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88839812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-11DOI: 10.5890/JAND.2016.03.009
H. Fujii, S. Okawa, K. Nadamoto, E. Okada, Yukio Yamada, Y. Hoshi, Masao Watanabe
Biomedical optical imaging has a possibility of a comprehensive diagnosis of thyroid cancer in conjunction with ultrasound imaging. For improvement of the optical imaging, this study develops a higher order scheme for solving the time-dependent radiative transport equation (RTE) by use of the finite-difference and discrete-ordinate methods. The accuracy and efficiency of the developed scheme are examined by comparison with the analytical solutions of the RTE in homogeneous media. Then, the developed scheme is applied to describing photon migration in the human neck model. The numerical simulations show complex behaviors of photon migration in the human neck model due to multiple diffusive reflection near the trachea.
{"title":"Numerical modeling of photon migration in human neck based on the radiative transport equation","authors":"H. Fujii, S. Okawa, K. Nadamoto, E. Okada, Yukio Yamada, Y. Hoshi, Masao Watanabe","doi":"10.5890/JAND.2016.03.009","DOIUrl":"https://doi.org/10.5890/JAND.2016.03.009","url":null,"abstract":"Biomedical optical imaging has a possibility of a comprehensive diagnosis of thyroid cancer in conjunction with ultrasound imaging. For improvement of the optical imaging, this study develops a higher order scheme for solving the time-dependent radiative transport equation (RTE) by use of the finite-difference and discrete-ordinate methods. The accuracy and efficiency of the developed scheme are examined by comparison with the analytical solutions of the RTE in homogeneous media. Then, the developed scheme is applied to describing photon migration in the human neck model. The numerical simulations show complex behaviors of photon migration in the human neck model due to multiple diffusive reflection near the trachea.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89060545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-02-17DOI: 10.5506/APhysPolB.47.549
P. Kowalski, W. Wi'slicki, L. Raczy'nski, D. Alfs, T. Bednarski, P. Bialas, E. Czerwi'nski, A. Gajos, B. Glowacz, J. Jasi'nska, D. Kami'nska, G. Korcyl, T. Kozik, W. Krzemie'n, E. Kubicz, M. Mohammad, S. Nied'zwiecki, M. Palka, M. Pawlik-Nied'zwiecka, Z. Rudy, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, B. Zgardzi'nska, M. Zieli'nski, P. Moskal
A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET collaboration. In this article we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.
{"title":"Scatter fraction of the J-PET tomography scanner","authors":"P. Kowalski, W. Wi'slicki, L. Raczy'nski, D. Alfs, T. Bednarski, P. Bialas, E. Czerwi'nski, A. Gajos, B. Glowacz, J. Jasi'nska, D. Kami'nska, G. Korcyl, T. Kozik, W. Krzemie'n, E. Kubicz, M. Mohammad, S. Nied'zwiecki, M. Palka, M. Pawlik-Nied'zwiecka, Z. Rudy, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, B. Zgardzi'nska, M. Zieli'nski, P. Moskal","doi":"10.5506/APhysPolB.47.549","DOIUrl":"https://doi.org/10.5506/APhysPolB.47.549","url":null,"abstract":"A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET collaboration. In this article we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75477822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This Habilitationsschrift (Habilitation thesis) is focused on my research activities on medical applications of particle physics and was written in 2013 to obtain the Venia Docendi (Habilitation) in experimental physics at the University of Bern. It is based on selected publications, which represented at that time my major scientific contributions as an experimental physicist to the field of particle accelerators and detectors applied to medical diagnostics and therapy. The thesis is structured in two parts. In Part I, Chapter 1 presents an introduction to accelerators and detectors applied to medicine, with particular focus on cancer hadrontherapy and on the production of radioactive isotopes. In Chapter 2, my publications on medical particle accelerators are introduced and put into their perspective. In particular, high frequency linear accelerators for hadrontherapy are discussed together with the new Bern cyclotron laboratory. Chapter 3 is dedicated to particle detectors with particular emphasis on three instruments I contributed to propose and develop: segmented ionization chambers for hadrontherapy, a proton radiography apparatus with nuclear emulsion films, and a beam monitor detector for ion beams based on doped silica fibres. Selected research and review papers are contained in Part II. For copyright reasons, they are only listed and not reprinted in this on-line version. They are available on the websites of the journals.
{"title":"Particle Accelerators and Detectors for medical Diagnostics and Therapy","authors":"S. Braccini","doi":"10.7892/BORIS.75806","DOIUrl":"https://doi.org/10.7892/BORIS.75806","url":null,"abstract":"This Habilitationsschrift (Habilitation thesis) is focused on my research activities on medical applications of particle physics and was written in 2013 to obtain the Venia Docendi (Habilitation) in experimental physics at the University of Bern. It is based on selected publications, which represented at that time my major scientific contributions as an experimental physicist to the field of particle accelerators and detectors applied to medical diagnostics and therapy. The thesis is structured in two parts. In Part I, Chapter 1 presents an introduction to accelerators and detectors applied to medicine, with particular focus on cancer hadrontherapy and on the production of radioactive isotopes. In Chapter 2, my publications on medical particle accelerators are introduced and put into their perspective. In particular, high frequency linear accelerators for hadrontherapy are discussed together with the new Bern cyclotron laboratory. Chapter 3 is dedicated to particle detectors with particular emphasis on three instruments I contributed to propose and develop: segmented ionization chambers for hadrontherapy, a proton radiography apparatus with nuclear emulsion films, and a beam monitor detector for ion beams based on doped silica fibres. Selected research and review papers are contained in Part II. For copyright reasons, they are only listed and not reprinted in this on-line version. They are available on the websites of the journals.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75978005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-08-04DOI: 10.1007/978-94-017-7478-9_9
A. Postnikov, K. Moldosanov
{"title":"Phonon-assisted radiofrequency absorption by gold nanoparticles resulting in hyperthermia","authors":"A. Postnikov, K. Moldosanov","doi":"10.1007/978-94-017-7478-9_9","DOIUrl":"https://doi.org/10.1007/978-94-017-7478-9_9","url":null,"abstract":"","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"48 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89201546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnetic fields interact with biological cells affecting them in variety of ways which are usually hard to predict. Among them, it was observed that strong fields can align dividing cells in a preferred direction. It was also demonstrated that dividing cancer cells are effectively destroyed by applying electric fields in vivo with a success rate dependent on the cell-to-field orientation. Based on these facts, the present note aims to suggest the use of magnetic and electric fields for improved cancer treatment. Several possibilities of generating the electric fields inside the magnetic field volume are reviewed, main tentative approaches are described and discussed. Most if not all of them require special magnet configuration research which can be based on existing magnet systems in operation or in development.
{"title":"Extended use of superconducting magnets for bio-medical development","authors":"Stoyan Stoynev","doi":"10.2172/1251187","DOIUrl":"https://doi.org/10.2172/1251187","url":null,"abstract":"Magnetic fields interact with biological cells affecting them in variety of ways which are usually hard to predict. Among them, it was observed that strong fields can align dividing cells in a preferred direction. It was also demonstrated that dividing cancer cells are effectively destroyed by applying electric fields in vivo with a success rate dependent on the cell-to-field orientation. Based on these facts, the present note aims to suggest the use of magnetic and electric fields for improved cancer treatment. Several possibilities of generating the electric fields inside the magnetic field volume are reviewed, main tentative approaches are described and discussed. Most if not all of them require special magnet configuration research which can be based on existing magnet systems in operation or in development.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"2016 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86604058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The fundamentals of near infrared spectroscopy (NIRS) are reviewed. Among the major factors controlling the cerebral blood flow (CBF), the effect of PaCO2 is peculiar in that it violates autoregulatory CBF mechanisms and allows to explore the full range of the CBF. A simple physical model, with a four parameter formula, relating the CBF to PaCO2 is presented. It can be used to transform the fits of one animal to the fits of another one. It enable the use of rats data as monkeys data simply by rescaling the PaCO2 values and the CBF data. Controlled breathing can change the PaCO2. Experiments on human subjects relating the PaCO2 to rSO2, measured with brain oximeters, are presented. A simple model relating the mean blood pressure to CBF is worked out.
{"title":"Probing Brain Oxygenation with Near Infrared Spectroscopy (NIRS) — The Role of Carbon Dioxide and Blood Pressure","authors":"A. Gersten","doi":"10.5772/59113","DOIUrl":"https://doi.org/10.5772/59113","url":null,"abstract":"The fundamentals of near infrared spectroscopy (NIRS) are reviewed. Among the major factors controlling the cerebral blood flow (CBF), the effect of PaCO2 is peculiar in that it violates autoregulatory CBF mechanisms and allows to explore the full range of the CBF. A simple physical model, with a four parameter formula, relating the CBF to PaCO2 is presented. It can be used to transform the fits of one animal to the fits of another one. It enable the use of rats data as monkeys data simply by rescaling the PaCO2 values and the CBF data. Controlled breathing can change the PaCO2. Experiments on human subjects relating the PaCO2 to rSO2, measured with brain oximeters, are presented. A simple model relating the mean blood pressure to CBF is worked out.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"229 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78773812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-21DOI: 10.1007/978-3-540-89208-3_68
Omid Ghasemalizadeh, M. Mirzaee, B. Firoozabadi, B. Sajadi, Ali Zolfonoon
{"title":"Beat Pressure and Comparing it with Ascending Aorta Pressure in Normal and Abnormal Conditions","authors":"Omid Ghasemalizadeh, M. Mirzaee, B. Firoozabadi, B. Sajadi, Ali Zolfonoon","doi":"10.1007/978-3-540-89208-3_68","DOIUrl":"https://doi.org/10.1007/978-3-540-89208-3_68","url":null,"abstract":"","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"185 1","pages":"276-285"},"PeriodicalIF":0.0,"publicationDate":"2014-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73377468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-21DOI: 10.14704/NQ.2016.14.1.902
A. Tanir, O. Gulec, E. Şahiner, M. H. Bolukdemir, Kemal Koç, N. Meriç, Sule Kaya Kelec
Our purpose is to measure the internal radiation dose (ID) using human blood sample. In the literature, there is no process that allows the direct measurement of ID received by a person. This study has shown that it is possible to determine ID in human blood exposed to internal or external ionizing radiation treatment both directly and retrospectively. OSL technique was used to measure the total dose from the blood sample. OSL counts from the waste blood of the patient injected with a radiopharmaceutical for diagnostic or treatment purposes and from a blood sample having a laboratory-injected radiation dose were both used for measurements. The decay and dose-response curves (DRC) were plotted for different doses. The doses received by different blood aliquots have been determined by interpolating the natural luminescence counts to DRC. In addition, OSL counts from a healthy blood sample exposed to an external radiation source were measured. The blood aliquots were given different 0-200Gy beta doses and their decay and dose-response curves were plotted. The internal dose received by the blood aliquots injected with radioisotope was determined by interpolating the natural luminescence counts to DRC. The internal dose values were found as 0.46Gy and 0.51Gy for different dose range. The blood aliquots were exposed to different external laboratory doses. The internal dose values corresponding to 10Gy laboratory dose from the aliquots exposed to external radiation were found as 10.94Gy for Disc3 and ~10.79Gy for Disc1.This study shows that the dose received by a person can be measured directly, simply and retrospectively by using only a very small amount of blood sample. The results will have important ramifications for the medicine and healthcare fields in particular.
{"title":"Direct determination of radiation dose in human blood","authors":"A. Tanir, O. Gulec, E. Şahiner, M. H. Bolukdemir, Kemal Koç, N. Meriç, Sule Kaya Kelec","doi":"10.14704/NQ.2016.14.1.902","DOIUrl":"https://doi.org/10.14704/NQ.2016.14.1.902","url":null,"abstract":"Our purpose is to measure the internal radiation dose (ID) using human blood sample. In the literature, there is no process that allows the direct measurement of ID received by a person. This study has shown that it is possible to determine ID in human blood exposed to internal or external ionizing radiation treatment both directly and retrospectively. OSL technique was used to measure the total dose from the blood sample. OSL counts from the waste blood of the patient injected with a radiopharmaceutical for diagnostic or treatment purposes and from a blood sample having a laboratory-injected radiation dose were both used for measurements. The decay and dose-response curves (DRC) were plotted for different doses. The doses received by different blood aliquots have been determined by interpolating the natural luminescence counts to DRC. In addition, OSL counts from a healthy blood sample exposed to an external radiation source were measured. The blood aliquots were given different 0-200Gy beta doses and their decay and dose-response curves were plotted. The internal dose received by the blood aliquots injected with radioisotope was determined by interpolating the natural luminescence counts to DRC. The internal dose values were found as 0.46Gy and 0.51Gy for different dose range. The blood aliquots were exposed to different external laboratory doses. The internal dose values corresponding to 10Gy laboratory dose from the aliquots exposed to external radiation were found as 10.94Gy for Disc3 and ~10.79Gy for Disc1.This study shows that the dose received by a person can be measured directly, simply and retrospectively by using only a very small amount of blood sample. The results will have important ramifications for the medicine and healthcare fields in particular.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76701459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Selective hysteretic heating of multiple collocated sets of single domain magnetic nanoparticles (SDMNPs) by alternating magnetic fields (AMFs) may offer a useful tool for biomedical applications. The possibility of magnetothermal multiplexing has not yet been realized, in part due to prevalent use of linear response theory to model SDMNP heating in AMFs. Predictive successes of dynamic hysteresis (DH), a more generalized model for heat dissipation by SDMNPs, are observed experimentally with detailed calorimetry measurements performed at varied AMF amplitudes and frequencies. The DH model suggests that specific driving conditions play an underappreciated role in determining optimal material selection strategies for high heat dissipation. Motivated by this observation, magnetothermal multiplexing is theoretically predicted and empirically demonstrated for the first time by selecting SDMNPs with properties that suggest optimal hysteretic heat dissipation at dissimilar AMF driving conditions. This form of multiplexing could effectively create multiple channels for minimally invasive biological signaling applications.
{"title":"Magnetically Multiplexed Heating of Single Domain Nanoparticles","authors":"M. G. Christiansen, Ritchie Chen, P. Anikeeva","doi":"10.1063/1.4879842","DOIUrl":"https://doi.org/10.1063/1.4879842","url":null,"abstract":"Selective hysteretic heating of multiple collocated sets of single domain magnetic nanoparticles (SDMNPs) by alternating magnetic fields (AMFs) may offer a useful tool for biomedical applications. The possibility of magnetothermal multiplexing has not yet been realized, in part due to prevalent use of linear response theory to model SDMNP heating in AMFs. Predictive successes of dynamic hysteresis (DH), a more generalized model for heat dissipation by SDMNPs, are observed experimentally with detailed calorimetry measurements performed at varied AMF amplitudes and frequencies. The DH model suggests that specific driving conditions play an underappreciated role in determining optimal material selection strategies for high heat dissipation. Motivated by this observation, magnetothermal multiplexing is theoretically predicted and empirically demonstrated for the first time by selecting SDMNPs with properties that suggest optimal hysteretic heat dissipation at dissimilar AMF driving conditions. This form of multiplexing could effectively create multiple channels for minimally invasive biological signaling applications.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80115469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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