Measurement of the response of Gd2O2S:Tb phosphor to 6 MV x-rays.

abstract：:The most advanced delivery technique for proton radiotherapy is active spot scanning. So far, predominantly static targets have been treated with active spot scanning, since mobile targets in combination with dynamic treatment delivery can lead to interplay effects, causing inhomogeneous dose distributions. One way to...

journal_title：Physics in medicine and biology

authors： Knopf AC,Hong TS,Lomax A

更新日期：2011-11-21 00:00:00

abstract：:Dose calculation for radiotherapy with protons and heavier ions deals with a large volume of path integrals involving a scattering power of body tissue. This work provides a simple model for such demanding applications. There is an approximate linearity between RMS end-point displacement and range of incident particle...

journal_title：Physics in medicine and biology

authors： Kanematsu N

更新日期：2009-03-07 00:00:00

abstract：:Mitral and aortic valve replacement is a procedure which is common in cardiac surgery. Some of these replacement valves are mechanical and contain moving metal parts. Should the patient in whom such a valve has been implanted be involved in magnetic resonance imaging, there is a possible dangerous interaction between ...

journal_title：Physics in medicine and biology

authors： Robertson NM,Diaz-Gomez M,Condon B

更新日期：2000-12-01 00:00:00

abstract：:This paper presents calculated specific absorption rate (SAR) dosimetry in 4 and 8 week Japanese pregnant-woman models exposed to plane waves over the frequency range of 10 MHz-1.5 GHz. Two types of 2 mm spatial-resolution pregnant-woman models comprised a woman model, which is similar to the average-sized Japanese ad...

journal_title：Physics in medicine and biology

authors： Kawai H,Nagaoka T,Watanabe S,Saito K,Takahashi M,Ito K

更新日期：2010-01-07 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：:As automation in radiation oncology becomes more common, it is important to determine which algorithms are equivalent for a given workflow. Often, algorithm comparisons are performed in isolation; however, clinical context can provide valuable insight into the importance of algorithm features and error magnification i...

journal_title：Physics in medicine and biology

authors： Weppler S,Schinkel C,Kirkby C,Smith W

更新日期：2020-09-28 00:00:00

abstract：:By means of the viscoelastodynamic model for a two-layer solid-fluid system and a detailed account of the locally induced acoustic radiation force, a rational analytical and computational framework is established for the viscoelastic characterization of thin tissues from high-frequency ultrasound (HFUS) measurements. ...

journal_title：Physics in medicine and biology

authors： Guzina BB,Tuleubekov K,Liu D,Ebbini ES

更新日期：2009-07-07 00:00:00

abstract：:3D acquisition and reconstruction in positron emission tomography (PET) produce data with improved signal-to-noise ratios compared with conventional 2D slice-oriented methods. However, the sensitivity increase is accompanied by an increase in the number of scattered photons and random coincidences detected. This paper...

journal_title：Physics in medicine and biology

authors： Bailey DL,Meikle SR

更新日期：1994-03-01 00:00:00

abstract：:The interaction of biomedical ultrasound with spherical tumours in the human body is investigated using analytic methods which predict the angular distribution of the ultrasound scattered by the tumour. Both the tumour and the surrounding tissue are considered to be lossy elastic media, which support shear-wave modes ...

journal_title：Physics in medicine and biology

authors： Hinders MK,Collins JJ,Collins MM,Fang TM,Sandri GV

更新日期：1992-11-01 00:00:00

abstract：:An efficient registration strategy is described that aims to help solve delicate medical imaging registration problems. It consists of running several registration methods for each dataset and selecting the best one for each specific dataset, according to an evaluation criterion. Finally, the quality of the registrati...

journal_title：Physics in medicine and biology

authors： Tacchella JM,Roullot E,Lefort M,Cohen ME,Guillevin R,Petrirena G,Delattre JY,Habert MO,Yeni N,Kas A,Frouin F

更新日期：2014-11-21 00:00:00

abstract：:As a part of an ongoing effort to develop computerized planning tools for cryosurgery, an experimental study has been conducted to verify a recently developed numerical technique for bioheat transfer simulations. Experiments were performed on gelatin solution as a phantom material, using proprietary liquid-nitrogen cr...

journal_title：Physics in medicine and biology

authors： Rossi MR,Rabin Y

更新日期：2007-08-07 00:00:00

abstract：:Abdominal organ motion may lead to considerable uncertainties in pencil-beam scanning (PBS) proton therapy of pancreatic cancer. Beam gating, where irradiation only occurs in certain breathing phases in which the gating conditions are fulfilled, may be an option to reduce the interplay effect between tumor motion and ...

journal_title：Physics in medicine and biology

authors： Dolde K,Naumann P,Dávid C,Kachelriess M,Lomax AJ,Weber DC,Saito N,Burigo LN,Pfaffenberger A,Zhang Y

更新日期：2019-04-10 00:00:00

abstract：:Assessment of radiation absorbed dose to internal organs of the body from the intake of radionuclides or, in the medical setting through the injection of radiopharmaceuticals, is generally performed based upon reference biokinetic models or patient imaging data, respectively. Biokinetic models estimate the time course...

journal_title：Physics in medicine and biology

authors： Schwarz BC,Godwin WJ,Wayson MB,Dewji SA,Jokisch DW,Lee C,Bolch WE

更新日期：2020-11-03 00:00:00

abstract：:This study evaluated the cavitation activity induced by shock wave (SW) pulses, both in vitro and in vivo, based on the area measurements of echogenic regions observed in B-mode ultrasound images. Residual cavitation bubble clouds induced by SW pulses were detected as echogenic regions in B-mode images. The temporal e...

journal_title：Physics in medicine and biology

authors： Tu J,Matula TJ,Bailey MR,Crum LA

更新日期：2007-10-07 00:00:00

abstract：:A method to measure the detector-to-object distance from the images obtained with stationary high-spatial-resolution gamma-ray cameras for in vivo studies has been developed. It exploits the shift of the imaged object in the image plane, obtained at a certain tilt of the parallel-hole collimator. A linear dependence o...

journal_title：Physics in medicine and biology

authors： Uzunov N,Bello M,Boccaccio P,Moschini G,Bollini D,de Notaristefani F

更新日期：2006-05-07 00:00:00

abstract：:Our newly developed method using spatially and time-resolved reflectances can easily estimate the absorption coefficients of each layer in a two-layered medium if the thickness of the upper layer and the reduced scattering coefficients of the two layers are known a priori. We experimentally validated this method using...

journal_title：Physics in medicine and biology

authors： Shimada M,Sato C,Hoshi Y,Yamada Y

更新日期：2009-08-21 00:00:00

abstract：:The standard Fourier metrics used for assessing image quality in computed tomography (CT) use a planar (2D) formulation of the noise equivalent quanta (NEQ) without a specific concept to manage the influence of longitudinal resolution variations, thus create a bias in the comparison of image quality for different reco...

journal_title：Physics in medicine and biology

authors： Monnin P,Viry A,Verdun FR,Racine D

更新日期：2020-06-09 00:00:00

abstract：:The purpose of this work was to create a computational platform for studying motion in intensity modulated radiotherapy (IMRT). Specifically, the non-uniform rational B-spline (NURB) cardiac and torso (NCAT) phantom was modified for use in a four-dimensional Monte Carlo (4D-MC) simulation system to investigate the eff...

journal_title：Physics in medicine and biology

authors： McGurk R,Seco J,Riboldi M,Wolfgang J,Segars P,Paganetti H

更新日期：2010-03-07 00:00:00

abstract：:Arc-therapy is a dose delivery technique regularly applied in photon radiation therapy, and is currently subject of great interest for proton therapy as well. In this technique, proton beams are aimed at a tumor from different continuous ranges of incident directions (so called "arcs"). This technique can potentially ...

journal_title：Physics in medicine and biology

authors： Nesteruk KP,Bolsi A,Lomax AJ,Meer D,van de Water S,Schippers JM

更新日期：2021-01-26 00:00:00

abstract：:In order to analyse the respective roles of ion concentration and fractional volume of the interstitial compartment as determinants of the impedance, Z, of renal medullary tissue, a model was needed in which both these factors could be varied independently. An array of blood cell suspensions ions in saline (different ...

journal_title：Physics in medicine and biology

authors： Niewiadomski W,Sadowski J,Badzyńska B,Rasmussen SN

更新日期：1990-11-01 00:00:00

abstract：:The silicon photomultiplier (Si-PM) is a promising photo-detector for PET for use in magnetic resonance imaging (MRI) systems because it has high gain and is insensitive to static magnetic fields. Recently we developed a Si-PM-based depth-of-interaction PET system for small animals and performed simultaneous measureme...

journal_title：Physics in medicine and biology

authors： Yamamoto S,Watabe T,Watabe H,Aoki M,Sugiyama E,Imaizumi M,Kanai Y,Shimosegawa E,Hatazawa J

更新日期：2012-01-21 00:00:00

abstract：:The dielectric constant and conductivity of muscle, liver, spleen and kidney of cats in vivo and in situ immediately following the animal's death were measured at frequencies from 10 kHz to 100 MHz. A novel multi-ring capacitive sensor and a computer-controlled automatic network analyser (ANA) were employed. The resul...

journal_title：Physics in medicine and biology

authors： Surowiec A,Stuchly SS,Keaney M,Swarup A

更新日期：1986-08-01 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：:Beam tracking with scanned carbon ion radiotherapy achieves highly conformal target dose by steering carbon pencil beams to follow moving tumors using real-time magnetic deflection and range modulation. The purpose of this study was to evaluate the robustness of target dose coverage from beam tracking in light of posi...

journal_title：Physics in medicine and biology

authors： Eley JG,Newhauser WD,Richter D,Lüchtenborg R,Saito N,Bert C

更新日期：2015-02-21 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：:Accurate scatter correction is especially important for high-resolution 3D positron emission tomographies (PETs) such as high-resolution research tomograph (HRRT) due to large scatter fraction in the data. To address this problem, a fully 3D iterative scatter-corrected ordered subset expectation maximization (OSEM) in...

journal_title：Physics in medicine and biology

authors： Kim KS,Ye JC

更新日期：2011-08-07 00:00:00

abstract：:Monte Carlo simulation provides a valuable tool in performance assessment and optimization of system design parameters for PET scanners. SimSET is a popular Monte Carlo simulation toolkit that features fast simulation time, as well as variance reduction tools to further enhance computational efficiency. However, SimSE...

journal_title：Physics in medicine and biology

authors： Poon JK,Dahlbom ML,Casey ME,Qi J,Cherry SR,Badawi RD

更新日期：2015-02-07 00:00:00

abstract：:Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to system...

journal_title：Physics in medicine and biology

authors： Pojtinger S,Dohm OS,Kapsch RP,Thorwarth D

更新日期：2018-06-07 00:00:00

abstract：:For the treatment planning during intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT), beam fluence maps can be first optimized via fluence map optimization (FMO) under the given dose prescriptions and constraints to conformally deliver the radiation dose to the targets while sparin...

journal_title：Physics in medicine and biology

authors： Gao H

更新日期：2016-04-07 00:00:00

abstract：:This paper analyzes the radio frequencies (RF) exposure in the head tissues of children using a cellular handset or RF sources (a dipole and a generic handset) at 900, 1800, 2100 and 2400 MHz. Based on magnetic resonance imaging, child head models have been developed. The maximum specific absorption rate (SAR) over 10...

journal_title：Physics in medicine and biology

authors： Wiart J,Hadjem A,Wong MF,Bloch I

更新日期：2008-07-07 00:00:00