A neural network regression model for relative dose computation.

abstract：:Radiomic features achieve promising results in cancer diagnosis, treatment response prediction, and survival prediction. Our goal is to compare the handcrafted (explicitly designed) and deep learning (DL)-based radiomic features extracted from pre-treatment diffusion-weighted magnetic resonance images (DWIs) for predi...

journal_title：Physics in medicine and biology

authors： Fu J,Zhong X,Li N,Van Dams R,Lewis J,Sung K,Raldow AC,Jin J,Qi XS

更新日期：2020-04-02 00:00:00

abstract：:A mathematical procedure, using Fourier deconvolution, is described whereby diffusion-free proximity functions can be obtained from cloud-chamber data. Such non-diffused distributions can be used to obtain further microdosimetric and nanodosimetric quantities hitherto not available from experiments, thus making the cl...

journal_title：Physics in medicine and biology

authors： Zaider M,Minerbo GN

更新日期：1988-11-01 00:00:00

abstract：:Image-guided radiation therapy using implanted fiducial markers is a common solution for prostate localization to improve targeting accuracy. However, fiducials that are typically used for conventional photon radiotherapy cause large dose perturbations in patients who receive proton radiotherapy. A proposed solution h...

journal_title：Physics in medicine and biology

authors： Cheung J,Kudchadker RJ,Zhu XR,Lee AK,Newhauser WD

更新日期：2010-12-07 00:00:00

abstract：:An optimized configuration of multi-pinhole aperture can improve the spatial resolution and the sensitivity of pinhole SPECT simultaneously. In this study, an optimization strategy of the multi-pinhole configuration with a small detector is proposed for mouse cardiac imaging. A 14 mm-diameter spherical field-of-view (...

journal_title：Physics in medicine and biology

authors： Lee MW,Lin WT,Chen YC

更新日期：2015-01-21 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：:Various lead attenuation techniques to determine the fast neutron sensitivity kU of a photon dosemeter are reviewed and a modified method is proposed to determine the kU value of a commercially available Geiger--Müller detector. The dependence on the 'effective' photon energy of the gamma-component of the mixed n--gam...

journal_title：Physics in medicine and biology

authors： Hough JH

更新日期：1979-07-01 00:00:00

abstract：:Focused ultrasound and microbubbles have been extensively used to generate therapeutic bioeffects. Despite encouraging in vivo results, there remains poor control of the magnitude and spatial distribution of these bioeffects due to the limited ability of conventional pulse shapes and sequences to control cavitation dy...

journal_title：Physics in medicine and biology

authors： Pouliopoulos AN,Bonaccorsi S,Choi JJ

更新日期：2014-11-21 00:00:00

abstract：:The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were impl...

journal_title：Physics in medicine and biology

authors： Hornblower VD,Yu E,Fenster A,Battista JJ,Malthaner RA

更新日期：2007-01-07 00:00:00

abstract：:This study verifies the concept of the super-omni wedge by validating its equations for effective wedge orientation and wedge angle and by comparing the dose distributions it produces with those produced by other wedge techniques. To validate the equations, we calculated dose distributions for 20 combinations of wedge...

journal_title：Physics in medicine and biology

authors： Dai J,Zhu Y,Wu X

更新日期：2001-09-01 00:00:00

abstract：:We propose a method to compensate for six degree-of-freedom rigid motion in helical CT of the head. The method is demonstrated in simulations and in helical scans performed on a 16-slice CT scanner. Scans of a Hoffman brain phantom were acquired while an optical motion tracking system recorded the motion of the bed an...

journal_title：Physics in medicine and biology

authors： Kim JH,Nuyts J,Kyme A,Kuncic Z,Fulton R

更新日期：2015-03-07 00:00:00

abstract：:Magnetic resonance and ultrasound elastography techniques are now important tools for staging high-grade fibrosis in patients with chronic liver disease. However, uncertainty remains about the effects of simple accumulation of fat (steatosis) and inflammation (steatohepatitis) on the parameters that can be measured us...

journal_title：Physics in medicine and biology

authors： Parker KJ,Ormachea J,Drage MG,Kim H,Hah Z

更新日期：2018-05-17 00:00:00

abstract：:Dental tomographic cone-beam x-ray imaging devices record truncated projections and reconstruct a region of interest (ROI) inside the head. Image reconstruction from the resulting local tomography data is an ill-posed inverse problem. A new Bayesian multiresolution method is proposed for local tomography reconstructio...

journal_title：Physics in medicine and biology

authors： Niinimäki K,Siltanen S,Kolehmainen V

更新日期：2007-11-21 00:00:00

abstract：:In this work, a procedure, based on Monte Carlo techniques, to analyse the effect on the tumour control probability of the time interval between surgery and postoperative radiotherapy is presented. The approach includes the tumour growth as well as the survival of tumour cells undergoing fractionated radiotherapy. Bot...

journal_title：Physics in medicine and biology

authors： Al-Dweri FM,Guirado D,Lallena AM,Pedraza V

更新日期：2004-07-07 00:00:00

abstract：:This work aims to develop, implement and validate a Monte Carlo (MC)-based independent dose calculation (IDC) framework to perform patient-specific quality assurance (QA) for multi-leaf collimator (MLC)-based CyberKnife® (Accuray Inc., Sunnyvale, CA) treatment plans. The IDC framework uses an XML-format treatment plan...

journal_title：Physics in medicine and biology

authors： Mackeprang PH,Vuong D,Volken W,Henzen D,Schmidhalter D,Malthaner M,Mueller S,Frei D,Stampanoni MFM,Dal Pra A,Aebersold DM,Fix MK,Manser P

更新日期：2017-12-19 00:00:00

abstract：:In treatment planning we depend upon accurate knowledge of geometric and range uncertainties. If the uncertainty model is inaccurate then the plan will produce under-dosing of the target and/or overdosing of OAR. We aim to provide a method for which centre and site-specific population range uncertainty due to inter-fr...

journal_title：Physics in medicine and biology

authors： Holloway SM,Holloway MD,Thomas SJ

更新日期：2017-12-19 00:00:00

abstract：:Over the last 50 years, diagnostic imaging has grown from a state of infancy to a high level of maturity. Many new imaging modalities have been developed. However, modern medical imaging includes not only image production but also image processing, computer-aided diagnosis (CAD), image recording and storage, and image...

journal_title：Physics in medicine and biology

authors： Doi K

更新日期：2006-07-07 00:00:00

abstract：:Four-dimensional volumetric modulated arc therapy (4D VMAT) is a treatment strategy for lung cancers that aims to exploit relative target and tissue motion to improve organ at risk (OAR) sparing. The algorithm incorporates the entire patient respiratory cycle using 4D CT data into the optimization process. Resulting t...

journal_title：Physics in medicine and biology

authors： Chin E,Loewen SK,Nichol A,Otto K

更新日期：2013-02-21 00:00:00

abstract：:Techniques for reducing computation time in 3D photon dose calculations are addressed with specific emphasis given to the convolution/superposition approach. A single polyenergetic superposition model calculating absorbed dose per incident photon fluence (Gy cm2) was developed in terms of TERMA and a total energy depo...

journal_title：Physics in medicine and biology

authors： Aspradakis MM,Redpath AT

更新日期：1997-08-01 00:00:00

abstract：:Radiochromic films are useful as dosimeters in high-precision radiotherapy owing to their high spatial resolution. However, when a particle beam is measured using a radiochromic film, the dose cannot be estimated accurately because the film darkness varies with variations in linear energy transfer (LET). This paper pr...

journal_title：Physics in medicine and biology

authors： Kawashima M,Matsumura A,Souda H,Tashiro M

更新日期：2020-06-15 00:00:00

abstract：:The incorporation of accurately aligned anatomical information as a prior to guide reconstruction and noise regularization in positron emission tomography (PET) has been suggested in many previous studies. However, the advantages of this approach can only be realized if the exact lesion outline is also available. In p...

journal_title：Physics in medicine and biology

authors： Chan C,Fulton R,Feng DD,Meikle S

更新日期：2009-12-21 00:00:00

abstract：:Large blood vessels can produce steep temperature gradients in heated tissues leading to inadequate tissue temperatures during hyperthermia. This paper utilizes a finite difference scheme to solve the basic equations of heat transfer and fluid flow to model blood vessel cooling. Unlike previous formulations, heat tran...

journal_title：Physics in medicine and biology

authors： Kolios MC,Sherar MD,Hunt JW

更新日期：1995-04-01 00:00:00

abstract：:In proton scanning systems that employ active energy variation for depth modulation, a switch of the particle energy might typically require 1-2 s. For plans comprising many energy slices, these seconds could sum up to a non-negligible fraction of the total treatment duration. We have applied the Nyquist-Shannon sampl...

journal_title：Physics in medicine and biology

authors： Kang JH,Wilkens JJ,Oelfke U

更新日期：2008-05-07 00:00:00

abstract：:Effective detective quantum efficiency (eDQE) describes the resolution and noise properties of an imaging system along with scatter and primary transmission, all measured under clinically appropriate conditions. Effective dose efficiency (eDE) is the eDQE normalised to mean glandular dose and has been proposed as a us...

journal_title：Physics in medicine and biology

authors： Wood TJ,Moore CS,Saunderson JR,Beavis AW

更新日期：2018-01-16 00:00:00

abstract：:We evaluated the basic properties of a commercially available BANGkit gel dosimeter, which is a normoxic type of BANG gel. This gel-kit has the same composition as the BANG 3 gel, but is fully oxygenated. To exclude oxygen, oxygen scavenging ascorbic acid and copper sulfate as a catalyst are used. The properties that ...

journal_title：Physics in medicine and biology

authors： Murakami Y,Nakashima T,Watanabe Y,Akimitsu T,Matsuura K,Kenjo M,Kaneyasu Y,Wadasaki K,Hirokawa Y,Ito K

更新日期：2007-04-21 00:00:00

abstract：:Recent measurements of differential elastic and inelastic neutron scattering from oxygen, nitrogen and calcium at 18 less than En less than 26 MeV are presented and analysed in terms of the optical model. These data, together with earlier measurements of scattering and total cross sections, are used to construct model...

journal_title：Physics in medicine and biology

authors： Islam MS,Finlay RW,Petler JS,Rapaport J,Alarcon R,Wierzbicki J

更新日期：1988-03-01 00:00:00

abstract：:Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensiti...

journal_title：Physics in medicine and biology

authors： Makarova A,Gottschalk B,Sauerwein W

更新日期：2017-07-06 00:00:00

abstract：:The temperature sensitivities of absorption and reduced scattering coefficients in the range 700-1000 nm are determined for the liquid phantom Intralipid using spatially resolved continuous wave measurements. The measurements were conducted on a 10 L heated volume of 1% Intralipid subjected to a 40-30 degrees C coolin...

journal_title：Physics in medicine and biology

authors： McGlone VA,Martinsen P,Künnemeyer R,Jordan B,Cletus B

更新日期：2007-05-07 00:00:00

abstract：:Stereotactic Gamma Knife radiosurgery utilizes ionizing beams from (60)Co sources and relies on a combination of collimator sizes, weighting, etc to generate a high-dose region that is conformal with a designated target volume. Dose computation is typically performed by computer, but in this paper, single collimator d...

journal_title：Physics in medicine and biology

authors： Fenner J,Gwilliam M,Mehrem R,Bird A,Walton L

更新日期：2008-04-21 00:00:00

abstract：:Blood was withdrawn from the ante-cubital vein of five normal volunteers and the erythrocytes were washed and resuspended in isotonic saline. The rate of descent of the erythrocyte-saline boundary was measured every hour for a period of at least 4 h for different suspended cell concentrations. The velocity of this bou...

journal_title：Physics in medicine and biology

authors： Smallwood RH,Tindale WB,Trowbridge EA

更新日期：1985-02-01 00:00:00

abstract：:Although the calculation of the surface average of the low-frequency current density distribution over a cross-section of 1 cm2 is required by ICNIRP guidelines, no reference averaging algorithm is indicated, neither in the ICNIRP guidelines nor in the Directive 2004/40/EC that is based on them. The lack of a general ...

journal_title：Physics in medicine and biology

authors： Zoppetti N,Andreuccetti D

更新日期：2009-08-07 00:00:00