Benchmarking GATE/Geant4 for 16O ion beam therapy.

abstract：:For plane-parallel chambers used in electron dosimetry, modern dosimetry protocols recommend a cross-calibration against a calibrated cylindrical chamber. The rationale for this is the unacceptably large (up to 3-4%) chamber-to-chamber variations of the perturbation factors (pwall)Co, which have been reported for plan...

journal_title：Physics in medicine and biology

authors： Kapsch RP,Bruggmoser G,Christ G,Dohm OS,Hartmann GH,Schüle E

更新日期：2007-12-07 00:00:00

abstract：:In this paper, we have investigated the feasibility of imaging the mechanical behavior of poroelastic materials using axial strain elastography. Cylindrical samples obtained from poroelastic materials having different elastic and permeability properties were subjected to a constant compression force (a classical creep...

journal_title：Physics in medicine and biology

authors： Righetti R,Righetti M,Ophir J,Krouskop TA

更新日期：2007-06-07 00:00:00

abstract：:A method has been developed which, by using the geometric information from treatment sample cases, selects from a given data set an initial treatment plan as a step for treatment plan optimization. The method uses an artificial neural network (ANN) classification technique to select a best matching plan from the 'opti...

journal_title：Physics in medicine and biology

authors： Hosseini-Ashrafi ME,Bagherebadian H,Yahaqi E

更新日期：1999-06-01 00:00:00

abstract：:Calibration methods are investigated for the determination of bone density by the Compton scattering method. The scattered radiation from materials of different densities and dimensions is measured for this purpose. A function for the dependence of the intensity on these parameters is derived and compared with the exp...

journal_title：Physics in medicine and biology

authors： Leichter I,Weinreb A,Hazan G

更新日期：1980-07-01 00:00:00

abstract：:K line x-ray fluorescence (KXRF) measurements of bone lead have emerged as a promising new biological marker of internal lead dose in epidemiological studies. Some disagreements exist, however, over the analysis of data at low levels of bone lead concentration. In this study, we performed 30 serial measurements on eac...

journal_title：Physics in medicine and biology

authors： Kim R,Aro A,Rotnitzky A,Amarasiriwardena C,Hu H

更新日期：1995-09-01 00:00:00

abstract：:A hybrid proportional-integral-in-time and cost-minimizing-in-space feedback control system for electromagnetic, deep regional hyperthermia is proposed. The unique features of this controller are that (1) it uses temperature, not specific absorption rate, as the criterion for selecting the relative phases and amplitud...

journal_title：Physics in medicine and biology

authors： Kowalski ME,Jin JM

更新日期：2003-03-07 00:00:00

abstract：:The dynamic magnetization of immobilized spherical single-domain magnetic nanoparticles (MNPs) with uniaxial or cubic magnetocrystalline anisotropy was studied computationally by executing simulations based on the Landau-Lifshitz-Gilbert (LLG) equation. For situations when a static magnetic field was suddenly applied ...

journal_title：Physics in medicine and biology

authors： Zhao Z,Garraud N,Arnold DP,Rinaldi C

更新日期：2020-01-17 00:00:00

abstract：:Coincidence resolving time (CRT) is one of the most important physical-performance measures for positron emission tomography (PET), as reconstruction with accurate time-of-flight information enhances the lesion detectability in patient studies. Accordingly, various PET detector designs and high-performance front-end r...

journal_title：Physics in medicine and biology

authors： Park H,Lee S,Ko GB,Lee JS

更新日期：2018-12-10 00:00:00

abstract：:Generally, the inverse planning of radiation therapy consists mainly of the fluence optimization. The beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) consists of selecting appropriate radiation incidence directions and may influence the quality of the IMRT plans, both to enhance better or...

journal_title：Physics in medicine and biology

authors： Rocha H,Dias JM,Ferreira BC,Lopes MC

更新日期：2013-05-07 00:00:00

abstract：:An ultrahigh-resolution full-field optical coherence tomography (OCT) system has been developed for cellular-level imaging of biological media. The system is based on a Linnik interference microscope illuminated with a tungsten halogen lamp, associated with a high-resolution CCD camera. En face tomographic images are ...

journal_title：Physics in medicine and biology

authors： Dubois A,Moneron G,Grieve K,Boccara AC

更新日期：2004-04-07 00:00:00

abstract：:An inverse radiation treatment planning algorithm for Sensus Healthcare's SculpturaTM electronic brachytherapy system has been designed. The algorithm makes use of simulated annealing to optimize the conformation number of the treatment plan. The highly anisotropic dose distributions produced by the SculpturaTM x-ray ...

journal_title：Physics in medicine and biology

authors： Badali DS,Vainer Y,Ellenor CW,Mitchell CR,Fishman K,Soro N,Price R,Funk T

更新日期：2021-01-11 00:00:00

abstract：:We discuss the use of terahertz time domain spectroscopy for studies of conformational flexibility and conformational change in biomolecules. Protein structural dynamics are vital to biological function with protein flexibility affecting enzymatic reaction rates and sensory transduction cycling times. Conformational m...

journal_title：Physics in medicine and biology

authors： Markelz A,Whitmire S,Hillebrecht J,Birge R

更新日期：2002-11-07 00:00:00

abstract：:The purpose of this work is the clinical commissioning of a recently developed in vivo range verification system (IRVS) for treatment of prostate cancer by anterior and anterior oblique proton beams. The IRVS is designed to perform a complete workflow for pre-treatment range verification and adjustment. It contains sp...

journal_title：Physics in medicine and biology

authors： Hoesl M,Deepak S,Moteabbed M,Jassens G,Orban J,Park YK,Parodi K,Bentefour EH,Lu HM

更新日期：2016-04-21 00:00:00

abstract：:Many applications in medical imaging include image registration for matching of images from the same or different modalities. In the case of full data sampling, the respective reconstructed images are usually of such a good image quality that standard deformable volume-to-volume (3D-3D) registration approaches can be ...

journal_title：Physics in medicine and biology

authors： Flach B,Brehm M,Sawall S,Kachelrieß M

更新日期：2014-12-21 00:00:00

abstract：:There are three ways to determine the spectrum of a clinical photon beam: direct measurement, modelling the source and reconstruction from ion-chamber measurements. We focus on reconstruction because the necessary equipment is readily available and it provides independent confirmation of source models for a given mach...

journal_title：Physics in medicine and biology

authors： Armbruster B,Hamilton RJ,Kuehl AK

更新日期：2004-11-21 00:00:00

abstract：:It is not feasible to define very small or complex organs and tissues in the current voxel-type adult reference computational phantoms of the International Commission on Radiological Protection (ICRP), which limit dose coefficients for weakly penetrating radiations. To address the problem, the ICRP is converting the v...

journal_title：Physics in medicine and biology

authors： Kim HS,Yeom YS,Nguyen TT,Choi C,Han MC,Lee JK,Kim CH,Zankl M,Petoussi-Henss N,Bolch WE,Lee C,Qiu R,Eckerman K,Chung BS

更新日期：2017-03-21 00:00:00

abstract：:A dedicated small-animal x-ray micro computed tomography (micro-CT) system has been developed to screen laboratory small animals such as mice and rats. The micro-CT system consists of an indirect-detection flat-panel x-ray detector with a field-of-view of 120 x 120 mm2, a microfocus x-ray source, a rotational subject ...

journal_title：Physics in medicine and biology

authors： Lee SC,Kim HK,Chun IK,Cho MH,Lee SY,Cho MH

更新日期：2003-12-21 00:00:00

abstract：:Scatter correction is a prerequisite for quantitative SPECT, but potentially increases noise. Monte Carlo simulations (EGS4) and physical phantom measurements were used to compare accuracy and noise properties of two scatter correction techniques: the triple-energy window (TEW), and the transmission dependent convolut...

journal_title：Physics in medicine and biology

authors： Narita Y,Eberl S,Iida H,Hutton BF,Braun M,Nakamura T,Bautovich G

更新日期：1996-11-01 00:00:00

abstract：:Over the last two years we have evaluated paediatric patient doses in projection radiography derived from exposure level (EL) in computed radiography (CR) in a large university hospital. Entrance surface air kerma (ESAK) for 3501 paediatric examinations was calculated from the EL, which is a dose index parameter relat...

journal_title：Physics in medicine and biology

authors： Vano E,Martinez D,Fernandez JM,Ordiales JM,Prieto C,Floriano A,Ten JI

更新日期：2008-06-21 00:00:00

abstract：:Silicon diodes have good spatial resolution, which makes them advantageous over ionization chambers for dosimetry in fields with high dose gradients. However, silicon diodes overrespond to low-energy photons, that are more abundant in scatter which increase with large fields and larger depths. We present a cavity-theo...

journal_title：Physics in medicine and biology

authors： Eklund K,Ahnesjö A

更新日期：2009-10-21 00:00:00

abstract：:Proton therapy is very sensitive to daily density changes along the pencil beam paths. The purpose of this study is to develop and evaluate an automated method for adaptation of IMPT plans to compensate for these daily tissue density variations. A two-step restoration method for 'densities-of-the-day' was created: (1)...

journal_title：Physics in medicine and biology

authors： Jagt T,Breedveld S,van de Water S,Heijmen B,Hoogeman M

更新日期：2017-06-07 00:00:00

abstract：:To monitor and strategically control energy deposition in magnetic resonance imaging (MRI), measured as a specific absorption rate (SAR), numerical methods using generic human models have been employed to estimate worst-case values. Radiofrequency (RF) sequences are therefore often designed conservatively with large s...

journal_title：Physics in medicine and biology

authors： Jin J,Liu F,Weber E,Crozier S

更新日期：2012-12-21 00:00:00

abstract：:The aim of this study is the evaluation of on-the-fly volume of intersection computation for system's geometry modelling in 3D PET image reconstruction. For this purpose we propose a simple geometrical model in which the cubic image voxels on the given Cartesian grid are approximated with spheres and the rectangular t...

journal_title：Physics in medicine and biology

authors： Lougovski A,Hofheinz F,Maus J,Schramm G,Will E,van den Hoff J

更新日期：2014-02-07 00:00:00

abstract：:This work investigates the attenuation of a proton beam to reconstruct the map of the linear attenuation coefficient of a material which is mainly caused by the inelastic interactions of protons with matter. Attenuation proton computed tomography (pCT) suffers from a poor spatial resolution due to multiple Coulomb sca...

journal_title：Physics in medicine and biology

authors： Quiñones CT,Létang JM,Rit S

更新日期：2016-05-07 00:00:00

abstract：:Dose to water (Dw) determination in clinical high-energy photon beams with ionization chambers calibrated in terms of absorbed dose to water has been proposed as an alternative to ionization chamber dosimetry based on air kerma calibrations. Dw in the clinical beam is derived using a kappaQ factor that scales the abso...

journal_title：Physics in medicine and biology

authors： Palmans H,Mondelaers W,Thierens H

更新日期：1999-03-01 00:00:00

abstract：:Raman spectroscopy is a potentially important clinical tool for real-time diagnosis of disease and in situ evaluation of living tissue. The purpose of this article is to review the biological and physical basis of Raman spectroscopy of tissue, to assess the current status of the field and to explore future directions....

journal_title：Physics in medicine and biology

authors： Hanlon EB,Manoharan R,Koo TW,Shafer KE,Motz JT,Fitzmaurice M,Kramer JR,Itzkan I,Dasari RR,Feld MS

更新日期：2000-02-01 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：:The architecture of multi-layer imagers (MLIs) can be exploited to provide megavoltage spectral imaging (MVSPI) for specific imaging tasks. In the current work, we investigated bone suppression and gold fiducial contrast enhancement as two clinical tasks which could be improved with spectral imaging. A method based on...

journal_title：Physics in medicine and biology

authors： Myronakis M,Hu YH,Fueglistaller R,Wang A,Baturin P,Huber P,Morf D,Star-Lack J,Berbeco R

更新日期：2018-05-10 00:00:00

abstract：:Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitive image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE)...

journal_title：Physics in medicine and biology

authors： Padgett R,Kotre CJ

更新日期：2004-03-21 00:00:00

abstract：:With the development of laser technology, laser-driven proton acceleration provides a new method for proton tumor therapy. However, it has not been applied in practice because of the wide and decreasing energy spectrum of laser-accelerated proton beams. In this paper, we propose an analytical model to reconstruct the ...

journal_title：Physics in medicine and biology

authors： Tao L,Zhu K,Zhu J,Xu X,Lin C,Ma W,Lu H,Zhao Y,Lu Y,Chen JE,Yan X

更新日期：2017-07-07 00:00:00