The local noise property in positron volume imaging and optimal conditions for the signal-to-noise ratio of the 3D reconstructed image.

abstract：:Determining accurate in vivo dosimetry in brachytherapy treatment with high dose gradients is challenging. Here we introduce, investigate, and characterize a novel in vivo dosimeter and readout technique with the potential to address this problem. A cylindrical (4 mm × 20 mm) tissue equivalent radiochromic dosimeter P...

journal_title：Physics in medicine and biology

authors： Vidovic AK,Juang T,Meltsner S,Adamovics J,Chino J,Steffey B,Craciunescu O,Oldham M

更新日期：2014-07-21 00:00:00

abstract：:Random coincidences can contribute substantially to the background in positron emission tomography (PET). Several estimation methods are being used for correcting them. The goal of this study was to investigate the validity of techniques for random coincidence estimation, with various low-energy thresholds (LETs). Sim...

journal_title：Physics in medicine and biology

authors： Torres-Espallardo I,Rafecas M,Spanoudaki V,McElroy DP,Ziegler SI

更新日期：2008-05-07 00:00:00

abstract：:Cavity theories are used to relate the dose in a medium to the dose in a cavity. No satisfactory analytical approach exists for the case of intermediate cavities, such as TLDs, when interface effects are important. Burlin proposed a general cavity theory that accounts for the cavity size but which ignores interface ef...

journal_title：Physics in medicine and biology

authors： Frujinoiu C

更新日期：2001-04-01 00:00:00

abstract：:Our aim is to investigate the impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging using a population of patient respiratory traces. A total of 1295 respiratory traces acquired during whole body PET/CT imaging were classified into three types according to the qualitative shape ...

journal_title：Physics in medicine and biology

authors： Liu C,Pierce LA 2nd,Alessio AM,Kinahan PE

更新日期：2009-12-21 00:00:00

abstract：:The formulation of intensity modulated radiation therapy (IMRT) planning aspects frequently uses the dose-volume histogram (DVH), whereas plan computations often happen in the more desirable convex IMRT optimization framework. Inspired by a recent publication of Zinchenko et al (2008 Phys. Med. Biol. 53 3231-50), this...

journal_title：Physics in medicine and biology

authors： Kratt K,Scherrer A

更新日期：2009-06-21 00:00:00

abstract：:Clinical cerebral blood flow (CBF) maps generated through dynamic- susceptibility contrast (DSC) magnetic resonance (MR) perfusion imaging are currently cross-calibrated with PET studies. The cross-calibration is achieved by rescaling the MR CBF values so that normal white matter CBF corresponds to 22 ml/100 g/min. Ex...

journal_title：Physics in medicine and biology

authors： Chen JJ,Frayne R,Smith MR

更新日期：2005-03-21 00:00:00

abstract：:Most tissue characterization methods use RF data originating from backscattering processes in the insonified tissue. Characterization of the tissue of a thin layer (e.g., an artery wall) poses problems because of the small amount of data available. The tissue layer may be so thin that there are no RF data that are not...

journal_title：Physics in medicine and biology

authors： Linssen FM,Hoeks AP,Brands PJ

更新日期：1991-10-01 00:00:00

abstract：:Amorphous silicon (aSi:H) flat panel detectors are prevalent in radiotherapy for megavoltage imaging tasks. Any clinical and dosimetrical application requires a well-defined dose response of the system to achieve meaningful results. Due to radiation damages, panels deteriorate and the linearity of pixel response to do...

journal_title：Physics in medicine and biology

authors： Huber S,Mooslechner M,Mitterlechner B,Weichenberger H,Serpa M,Sedlmayer F,Deutschmann H

更新日期：2013-09-21 00:00:00

abstract：:Intensity modulated proton radiotherapy (IMPT) can reduce the dose to critical structures by optimizing the distribution and intensity of individual pencil beams. The IMPT can be delivered by dynamically scanning a pencil beam with variable intensity and energy across the tumor target volume. The lateral penumbra of a...

journal_title：Physics in medicine and biology

authors： Safai S,Bortfeld T,Engelsman M

更新日期：2008-03-21 00:00:00

abstract：:The purpose of this study was to determine the performance of a single lutetium oxy-orthosilicate (LSO) crystal layer High Resolution Research Tomograph (HRRT) positron emission tomography (PET) scanner. The HRRT is a high resolution PET scanner designed for human brain and small animal imaging. The scanner consists o...

journal_title：Physics in medicine and biology

authors： Boellaard R,Buijs F,de Jong HW,Lenox M,Gremillion T,Lammertsma AA

更新日期：2003-02-21 00:00:00

abstract：:The x-ray exposure to patients has become a major concern in computed tomography (CT) and minimizing the radiation exposure has been one of the major efforts in the CT field. Due to plenty high-attenuation tissues in the human chest, under low-dose scan protocols, thoracic low-dose CT (LDCT) images tend to be severely...

journal_title：Physics in medicine and biology

authors： Chen Y,Yang Z,Hu Y,Yang G,Zhu Y,Li Y,Luo L,Chen W,Toumoulin C

更新日期：2012-05-07 00:00:00

abstract：:This work aims to evaluate the predictive strength of the relative seriality, parallel and Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) models regarding the incidence of radiation pneumonitis (RP), in a group of patients following lung cancer radiotherapy and also to examine their correlati...

journal_title：Physics in medicine and biology

authors： Tsougos I,Nilsson P,Theodorou K,Kjellén E,Ewers SB,Jarlman O,Lind BK,Kappas C,Mavroidis P

更新日期：2007-02-21 00:00:00

abstract：:A common dose-saving technique used in modern CT devices is automatic tube current modulation (TCM), which was originally designed to also reduce the dose in paediatric CT patients. In order to be able to deduce detailed organ doses of paediatric models, dose conversion coefficients normalized to CTDI(vol) for an eigh...

journal_title：Physics in medicine and biology

authors： Schlattl H,Zankl M,Becker J,Hoeschen C

更新日期：2012-10-21 00:00:00

abstract：:Imaging technologies that allow non-radiative visualization and quantification of apoptosis have a great potential for assessing therapy response, early diagnosis, and disease monitoring. Magnetic particle imaging (MPI), the direct imaging of magnetic nanoparticles as positive contrast agent and sole signal source, en...

journal_title：Physics in medicine and biology

authors： Liang X,Wang K,Du J,Tian J,Zhang H

更新日期：2020-09-24 00:00:00

abstract：:This paper explores fast reconstruction strategies for 3D time-of-flight (TOF) positron emission tomography (PET), based on 2D data rebinning. Starting from pre-corrected 3D TOF data, a rebinning algorithm estimates for each transaxial slice the 2D TOF sinogram that would have been acquired by a single-ring scanner. T...

journal_title：Physics in medicine and biology

authors： Defrise M,Casey ME,Michel C,Conti M

更新日期：2005-06-21 00:00:00

abstract：:The purpose of this study is to evaluate a new method to improve performance of computer-aided detection (CAD) schemes of screening mammograms with two approaches. In the first approach, we developed a new case based CAD scheme using a set of optimally selected global mammographic density, texture, spiculation, and st...

journal_title：Physics in medicine and biology

authors： Tan M,Aghaei F,Wang Y,Zheng B

更新日期：2017-01-21 00:00:00

abstract：:Few quantitative data are available on the kinetics of polymerization reactions in polymer gel (PAG) dosimeters and their long-term stability. Post-irradiation polymerization reactions have been found to continue for several weeks, posing questions regarding dosimeter stability and its achievement. In this paper we re...

journal_title：Physics in medicine and biology

authors： McJury M,Oldham M,Leach MO,Webb S

更新日期：1999-08-01 00:00:00

abstract：:None of the existing protocols or codes of practice for high-energy electron dosimetry take any account of the accelerator-generated bremsstrahlung always present in electron beams. This results in a systematic error in the derivation of the absorbed dose. The purpose of this study is to draw attention to this omissio...

journal_title：Physics in medicine and biology

authors： Klevenhagen SC

更新日期：1994-07-01 00:00:00

abstract：:Finite element (FE) modeling provides a useful tool to understand the mechanical behavior of complex tissues, such as cancers, in a variety of testing conditions. Although a number of numerical and analytical models for cancerous tumors are retrievable in the literature, none of these models is capable of completely d...

journal_title：Physics in medicine and biology

authors： Islam MT,Reddy JN,Righetti R

更新日期：2018-10-24 00:00:00

abstract：:A transformation method was investigated for applying the MIRD absorbed fraction to internal dose calculations for an individual. The transformation method consists of two parts, transformation of the target organ mass, and of the distance between source and target organs. The variation of the specific absorbed fracti...

journal_title：Physics in medicine and biology

authors： Yamaguchi H,Kato Y,Shiragai A

更新日期：1975-07-01 00:00:00

abstract：:During image-guided cancer radiation treatment, three-dimensional (3D) tumor volumetric information is important for treatment success. However, it is typically not feasible to image a patient's 3D tumor continuously in real time during treatment due to concern over excessive patient radiation dose. We present a new i...

journal_title：Physics in medicine and biology

authors： Mao S,Wu H,Sandison G,Fang S

更新日期：2017-02-21 00:00:00

abstract：:Computational modeling is an important tool in ultrasound imaging research, but realistic three-dimensional (3D) simulations can exceed the capabilities of serial computers. This paper uses a 3D simulator based on a k-space method that incorporates relaxation absorption and nonreflecting boundary conditions. The simul...

journal_title：Physics in medicine and biology

authors： Daoud MI,Lacefield JC

更新日期：2009-09-07 00:00:00

abstract：:Image reconstruction of ultrasound computed tomography based on the wave equation is able to show much more structural details than simpler ray-based image reconstruction methods. However, to invert the wave-based forward model is computationally demanding. To address this problem, we develop an efficient fully learne...

journal_title：Physics in medicine and biology

authors： Zhao W,Wang H,Gemmeke H,van Dongen KWA,Hopp T,Hesser J

更新日期：2020-11-27 00:00:00

abstract：:Two dosimetry protocols based on absorbed dose to water have recently been implemented: TG-51 and TRS-398. These protocols use different beam-quality indices: %dd(10)x and TPR20,10. The effect of electron contamination in measurements of %dd(10)x has been proposed as a disadvantage of the TG-51. For actual measurement...

journal_title：Physics in medicine and biology

authors： Lopez Medina A,Teijeiro A,Salvador F,Medal D,Vazquez J,Salgado M,Carrion MC

更新日期：2004-01-07 00:00:00

abstract：:The scope of this work was to develop a synthetic single crystal diamond dosimeter (SCDD-Pro) for accurate relative dose measurements of clinical proton beams in water. Monte Carlo simulations were carried out based on the MCNPX code in order to investigate and reduce the dose curve perturbation caused by the SCDD-Pro...

journal_title：Physics in medicine and biology

authors： Moignier C,Tromson D,de Marzi L,Marsolat F,García Hernández JC,Agelou M,Pomorski M,Woo R,Bourbotte JM,Moignau F,Lazaro D,Mazal A

更新日期：2017-07-07 00:00:00

abstract：:The distribution and transport of Hippuran is discussed. The activity leaving both kidneys has been calculated and compared with the bladder activity. It is shown that the Impulse Response Function of the ureter and bladder may be obtained by deconvolution, and data are presented relating to studies on one patient. ...

journal_title：Physics in medicine and biology

authors： Knesaurek K,Spaventi S

更新日期：1981-03-01 00:00:00

abstract：:In recent years, particle therapy has become a widely accepted form of cancer treatment and technological advances in beam delivery technology (i.e. pencil beam scanning (PBS)) have enabled the application of highly conformal dose distributions to static targets. Current research focuses on the possibilities for the t...

journal_title：Physics in medicine and biology

authors： Bernatowicz K,Lomax AJ,Knopf A

更新日期：2013-11-21 00:00:00

abstract：:Prompt γ-ray imaging with a knife-edge shaped slit camera provides the possibility of verifying proton beam range in tumor therapy. Dedicated experiments regarding the characterization of the camera system have been performed previously. Now, we aim at implementing the prototype into clinical application of monitoring...

journal_title：Physics in medicine and biology

authors： Priegnitz M,Barczyk S,Nenoff L,Golnik C,Keitz I,Werner T,Mein S,Smeets J,Vander Stappen F,Janssens G,Hotoiu L,Fiedler F,Prieels D,Enghardt W,Pausch G,Richter C

更新日期：2016-11-21 00:00:00

abstract：:Microbeam radiation therapy (MRT) is a treatment approach in radiation therapy where the treatment field is spatially fractionated into arrays of a few tens of micrometre wide planar beams of unusually high peak doses separated by low dose regions of several hundred micrometre width. In preclinical studies, this treat...

journal_title：Physics in medicine and biology

authors： Debus C,Oelfke U,Bartzsch S

更新日期：2017-10-19 00:00:00

abstract：:We implemented a hybrid scatter-correction method for 3D PET that combines two scatter-correction methods in a complementary way. The implemented scheme uses a method based on the discrimination of the energy of events (the estimation of trues method (ETM)) and an auxiliary method (the single scatter simulation method...

journal_title：Physics in medicine and biology

authors： Ferreira NC,Trébossen R,Lartizien C,Brulon V,Merceron P,Bendriem B

更新日期：2002-05-07 00:00:00