Arc-modulated radiation therapy based on linear models.

abstract：:Joint space morphology can be indicative of the risk, presence, progression, and/or treatment response of disease or trauma. We describe a novel methodology of characterizing joint space morphology in high-resolution 3D images (e.g. cone-beam CT (CBCT)) using a model based on elementary electrostatics that overcomes a...

journal_title：Physics in medicine and biology

authors： Cao Q,Thawait G,Gang GJ,Zbijewski W,Reigel T,Brown T,Corner B,Demehri S,Siewerdsen JH

更新日期：2015-02-07 00:00:00

abstract：:In this study, the quantitative accuracy of different attenuation correction strategies presently available for the High Resolution Research Tomograph (HRRT) was investigated. These attenuation correction methods differ in reconstruction and processing (segmentation) algorithms used for generating a micro-image from m...

journal_title：Physics in medicine and biology

authors： van Velden FH,Kloet RW,van Berckel BN,Molthoff CF,de Jong HW,Lammertsma AA,Boellaard R

更新日期：2008-01-07 00:00:00

abstract：:A novel transmission detector (IBA Dosimetry, Germany) developed as an IMRT quality assurance tool, intended for in vivo patient dose measurements, is studied here. The goal of this investigation is to use Monte Carlo techniques to characterize treatment beam parameters in the presence of the detector and to compare t...

journal_title：Physics in medicine and biology

authors： Asuni G,Jensen JM,McCurdy BM

更新日期：2011-02-21 00:00:00

abstract：:We present a new method for automated characterization of atherosclerotic plaque composition in ex vivo MRI. It uses MRI intensities as well as four other types of features: smoothed, gradient magnitude and Laplacian images at several scales, and the distances to the lumen and outer vessel wall. The ground truth for f...

journal_title：Physics in medicine and biology

authors： van Engelen A,Niessen WJ,Klein S,Groen HC,Verhagen HJ,Wentzel JJ,van der Lugt A,de Bruijne M

更新日期：2012-01-07 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：:Segmentation of liver in abdominal computed tomography (CT) is an important step for radiation therapy planning of hepatocellular carcinoma. Practically, a fully automatic segmentation of liver remains challenging because of low soft tissue contrast between liver and its surrounding organs, and its highly deformable s...

journal_title：Physics in medicine and biology

authors： Qin W,Wu J,Han F,Yuan Y,Zhao W,Ibragimov B,Gu J,Xing L

更新日期：2018-05-04 00:00:00

abstract：:A Monte Carlo computer program has been developed for the computation of integral radiation dose to the breast in xeromammography. The results are given in terms of the integral dose per unit area of the breast per unit incident exposure. The calculations have been made for monoenergetic incident photons and the resul...

journal_title：Physics in medicine and biology

authors： Dance DR

更新日期：1980-01-01 00:00:00

abstract：:It is difficult to test near-infrared spectrophotometry instruments in vivo. Therefore we constructed a liquid phantom which mimics the neonatal head. It consists of a spherical 3.5 mm thick layer of silicone rubber simulating skin and bone and a 0.5 mm thick clear layer of polypropylene imitating cerebrospinal fluid....

journal_title：Physics in medicine and biology

authors： Wolf M,Keel M,Dietz V,von Siebenthal K,Bucher HU,Baenziger O

更新日期：1999-07-01 00:00:00

abstract：:The implementation of two algorithms for calculating dose distributions for radiation therapy treatment planning of intermediate energy proton beams is described. A pencil kernel algorithm and a depth penetration algorithm have been incorporated into a commercial three dimensional treatment planning system (Helax-TMS,...

journal_title：Physics in medicine and biology

authors： Russell KR,Isacsson U,Saxner M,Ahnesjö A,Montelius A,Grusell E,Dahlgren CV,Lorin S,Glimelius B

更新日期：2000-01-01 00:00:00

abstract：:In medical imaging different techniques have been developed to gain information from inside a tissue. Optoacoustics is a method to generate tomography pictures of tissue using Q-switched laser pulses. Due to thermal and pressure confinement, a short light pulse generates a pressure distribution inside tissue, which mi...

journal_title：Physics in medicine and biology

authors： Köstli KP,Frenz M,Bebie H,Weber HP

更新日期：2001-07-01 00:00:00

abstract：:Dynamic modulation can be affected by inaccuracies when the required acceleration is larger than the highest allowed by the mechanical characteristics of the whole apparatus. In this study, inertia effects have been investigated with regard to the single absorber 1D modulation, analysing primarily how the acceleration...

journal_title：Physics in medicine and biology

authors： Corletto D,Broggi S,Fiorino C,Mangili P,Calandrino R,Lev A,Gennari D,Rudello F

更新日期：1999-11-01 00:00:00

abstract：:Biomechanical model based deformable image registration has been widely used to account for prostate deformation in various medical imaging procedures. Biomechanical material properties are important components of a biomechanical model. In this study, the effect of incorporating tumor-specific material properties in t...

journal_title：Physics in medicine and biology

authors： Samavati N,McGrath DM,Jewett MA,van der Kwast T,Ménard C,Brock KK

更新日期：2015-01-07 00:00:00

abstract：:Thermal ablation is a widely applied electrosurgical process in medical treatment of soft biological tissues. Numerical modeling and simulations play an important role in prediction of temperature distribution and damage volume during the treatment planning stage of associated therapies. In this contribution we report...

journal_title：Physics in medicine and biology

authors： Singh S,Melnik R

更新日期：2019-12-13 00:00:00

abstract：:A method for registering images acquired from a prototype flat panel mobile C-arm, capable of kilovoltage (kV) cone-beam computed tomography (CT), to a linear accelerator (LINAC) isocenter is presented. A calibration procedure is performed which involves locating reflective markers placed on the C-arm and a phantom in...

journal_title：Physics in medicine and biology

authors： Sorensen S,Mitschke M,Solberg T

更新日期：2007-06-21 00:00:00

abstract：:This paper describes the algorithm and examines the performance of an intensity-modulated radiation therapy (IMRT) beam-angle optimization (BAO) system. In this algorithm successive sets of beam angles are selected from a set of predefined directions using a fast simulated annealing (FSA) algorithm. An IMRT beam-profi...

journal_title：Physics in medicine and biology

authors： Djajaputra D,Wu Q,Wu Y,Mohan R

更新日期：2003-10-07 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：: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：:For treatments with dynamic intensity modulated radiotherapy (IMRT), the adjustment of multileaf collimator (MLC) parameters affecting both the optimization algorithm and dose distributions is crucial. The main parameters characterizing the MLC are the transmission (T) and the dosimetric leaf separation (DLS). The aim...

journal_title：Physics in medicine and biology

authors： Chauvet I,Petitfils A,Lehobey C,Kristner JY,Brunet Y,Lembrez R,Gaboriaud G,Mazal A,Zefkili S,Rosenwald JC

更新日期：2005-02-21 00:00:00

abstract：:The whole prostatic volume (PV) is an important indicator for benign prostate hyperplasia. Correlating the PV with other clinical parameters in a population-based prospective cohort study (SHIP-2) requires valid prostate segmentation in a large number of whole-body MRI scans. The axial proton density fast spin echo fa...

journal_title：Physics in medicine and biology

authors： Habes M,Schiller T,Rosenberg C,Burchardt M,Hoffmann W

更新日期：2013-09-07 00:00:00

abstract：PURPOSE:A system for long-length intraoperative imaging is reported based on longitudinal motion of an O-arm gantry featuring a multi-slot collimator. We assess the utility of long-length tomosynthesis and the geometric accuracy of 3D image registration for surgical guidance and evaluation of long spinal constructs. M...

journal_title：Physics in medicine and biology

authors： Zhang X,Uneri A,Wu P,Ketcha MD,Jones C,Huang Y,Lo SL,Helm PA,Siewerdsen JH

更新日期：2021-01-21 00:00:00

abstract：:Although physical metrics can objectively characterize computed tomography (CT) image quality, quantitative approaches to predict human observer performance are more accurate and clinically relevant. This study compared a modified channelized Hotelling model observer (CHO) with human observers in a shape discriminatio...

journal_title：Physics in medicine and biology

authors： Zhang Y,Leng S,Yu L,Carter RE,McCollough CH

更新日期：2014-07-07 00:00:00

abstract：:Magnetoencephalography (MEG) source analysis has largely relied on spherical conductor models of the head to simplify forward calculations of the brain's magnetic field. Multiple- (or overlapping, local) sphere models, where an optimal sphere is selected for each sensor, are considered an improvement over single-spher...

journal_title：Physics in medicine and biology

authors： Lalancette M,Quraan M,Cheyne D

更新日期：2011-09-07 00:00:00

abstract：:Ultrasound-based elastography including strain elastography, acoustic radiation force impulse (ARFI) imaging, point shear wave elastography and supersonic shear imaging (SSI) have been used to differentiate breast tumors among other clinical applications. The objective of this study is to extend a previously published...

journal_title：Physics in medicine and biology

authors： Wang Y,Peng B,Jiang J

更新日期：2017-03-07 00:00:00

abstract：:Ultrasonic speed of propagation and attenuation were investigated as a function of absorbed radiation dose in PAG and MAGIC polymer gel dosimeters. Both PAG and MAGIC gel dosimeters displayed a dependence of ultrasonic parameters on absorbed dose with attenuation displaying significant changes in the dose range invest...

journal_title：Physics in medicine and biology

authors： Mather ML,De Deene Y,Whittaker AK,Simon GP,Rutgers R,Baldock C

更新日期：2002-12-21 00:00:00

abstract：:This paper presents two methods for absorbed dose determination with ionization chambers at short distance from 60Co and 192Ir brachytherapy sources. The methods are modifications of the Bragg-Gray and large cavity principles given in the IAEA code of practice for high- and medium-energy photon beams. A non-uniformity...

journal_title：Physics in medicine and biology

authors： Tölli H,Johansson KA

更新日期：1998-11-01 00:00:00

abstract：:Monte Carlo simulation was used to calculate correction factors for output factor (OF), percentage depth-dose (PDD), and off-axis ratio (OAR) measurements with the CyberKnife M6 System. These include the first such data for the InCise MLC. Simulated detectors include diodes, air-filled microchambers, a synthetic micro...

journal_title：Physics in medicine and biology

authors： Francescon P,Kilby W,Noll JM,Masi L,Satariano N,Russo S

更新日期：2017-02-07 00:00:00

abstract：:DMSA imaging is carried out in nuclear medicine to assess the level of functional renal tissue in patients. This study investigated the use of an artificial neural network to perform diagnostic classification of these scans. Using the radiological report as the gold standard, the network was trained to classify DMSA s...

journal_title：Physics in medicine and biology

authors： Wright JW,Duguid R,McKiddie F,Staff RT

更新日期：2014-04-07 00:00:00

abstract：:Optical topography is a method for visualization of conical activity. Ways of improving the spatial resolution of the topographical image with three arrangements of optical fibres are discussed. A distribution of sensitivity is obtained from the phantom experiment, and used to reconstruct topographical images of an ac...

journal_title：Physics in medicine and biology

authors： Yamamoto T,Maki A,Kadoya T,Tanikawa Y,Yamad Y,Okada E,Koizumi H

更新日期：2002-09-21 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：:Andreo and Benmakhlouf (2017 Phys. Med. Biol. 62 1518-32) have disputed a finding of Scott et al (2012 Phys. Med. Biol. 57 4461-76) that the variation with field-size of the response of small ion chambers and solid-state dosimeters in small megavoltage photon radiation fields can largely be attributed to density. Furt...

journal_title：Physics in medicine and biology

authors： Fenwick JD,Georgiou G,Rowbottom CG,Underwood TSA,Kumar S

更新日期：2018-10-03 00:00:00