Electromagnetic redesign of the HYPERcollar applicator: toward improved deep local head-and-neck hyperthermia.

abstract：:Subharmonic contrast imaging promises to improve ultrasound-imaging quality by taking advantage of an increased contrast to tissue signal. However, acoustic pressures beyond the subharmonic generation threshold using common ultrasound pulses may induce significant contrast microbubble destruction. In this work, a chir...

journal_title：Physics in medicine and biology

authors： Zhang D,Gong Y,Gong X,Liu Z,Tan K,Zheng H

更新日期：2007-09-21 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：:The purpose of this study is to calculate Pareto surfaces in multi-criteria radiation treatment planning and to analyse the dependency of the Pareto surfaces on the objective functions used for the volumes of interest. We develop a linear approach that allows us to calculate truly Pareto optimal treatment plans, and w...

journal_title：Physics in medicine and biology

authors： Craft D,Halabi T,Bortfeld T

更新日期：2005-12-21 00:00:00

abstract：:Grating-based x-ray phase-contrast imaging provides three simultaneous image channels originating from a single image acquisition. While the phase signal provides direct access to the electron density in tomography, there is additional information on sub-resolutional structural information which is called dark-field s...

journal_title：Physics in medicine and biology

authors： Braig EM,Pfeiffer D,Willner M,Sellerer T,Taphorn K,Petrich C,Scholz J,Petzold L,Birnbacher L,Dierolf M,Pfeiffer F,Herzen J

更新日期：2020-09-18 00:00:00

abstract：:A Gaussian convolution kernel K is deduced as a Green's function of a Lie operator series. The deconvolution of a Gaussian kernel is developed by the inverse Green's function K(-1). A practical application is the deconvolution of measured profiles Dm(x) of photons and protons with finite detector size to determine the...

journal_title：Physics in medicine and biology

authors： Ulmer W,Kaissl W

更新日期：2003-03-21 00:00:00

abstract：:For proton therapy, an accurate conversion of CT HU to relative stopping power (RSP) is essential. Validation of the conversion based on real tissue samples is more direct than the current practice solely based on tissue substitutes and can potentially address variations over the population. Based on a novel dose exti...

journal_title：Physics in medicine and biology

authors： Zhang R,Baer E,Jee KW,Sharp GC,Flanz J,Lu HM

更新日期：2017-06-23 00:00:00

abstract：:A significant timer error has been found on a linear accelerator used for intraoperative radiation therapy. Since typical treatment doses range up to 20 Gy, calibrations that do not account for this effect can incur a large dosimetry error. The effect is dose rate dependent, but energy independent. For a dose rate of ...

journal_title：Physics in medicine and biology

authors： Biggs PJ

更新日期：1998-10-01 00:00:00

abstract：:First experimental results with energy-resolved computed tomography (CT) are reported. The contrast-to-noise ratio (CNR) in CT has been improved with x-ray energy weighting for the first time. Further, x-ray energy weighting improved the CNR in material decomposition CT when applied to CT projections prior to dual-ene...

journal_title：Physics in medicine and biology

authors： Shikhaliev PM

更新日期：2008-10-21 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：:Respiratory-correlated 4D-MRI can characterize respiratory-induced motion of tumors and organs-at-risk for radiotherapy treatment planning and is a necessity for image guidance of moving tumors treated on an MRI-linac. Essential for 4D-MRI generation is a robust respiratory surrogate signal. We investigated the feasib...

journal_title：Physics in medicine and biology

authors： Navest RJM,Mandija S,Bruijnen T,Stemkens B,Tijssen RHN,Andreychenko A,Lagendijk JJW,van den Berg CAT

更新日期：2020-01-13 00:00:00

abstract：:The relative biological effectiveness (RBE) of protons varies with multiple physical and biological factors. Phenomenological RBE models have been developed to include such factors in the estimation of a variable RBE, in contrast to the clinically applied constant RBE of 1.1. In this study, eleven published phenomenol...

journal_title：Physics in medicine and biology

authors： Rørvik E,Fjæra LF,Dahle TJ,Dale JE,Engeseth GM,Stokkevåg CH,Thörnqvist S,Ytre-Hauge KS

更新日期：2018-09-13 00:00:00

abstract：:The local noise property of a 3D PET reconstructed image is investigated for a uniform-activity sphere distributed in a constantly attenuating spherical object. The positional dependence of the statistical noise is approximately derived and calculated for some special cases. It is suggested that a larger diameter of t...

journal_title：Physics in medicine and biology

authors： Murayama H,Nohara N

更新日期：1997-01-01 00:00:00

abstract：:A formalism is proposed for the estimation of mean glandular dose for breast tomosynthesis, which is a simple extension of the UK, European and IAEA protocols for dosimetry in conventional projection mammography. The formalism introduces t-factors for the calculation of breast dose from a single projection and T-facto...

journal_title：Physics in medicine and biology

authors： Dance DR,Young KC,van Engen RE

更新日期：2011-01-21 00:00:00

abstract：:Current dosimetry protocols (AAPM, IAEA, DIN) recommend the use of parallel-plate ionization chambers for the measurement of absorbed dose-to-water in clinical electron beams. For well-guarded plane-parallel chambers, it is assumed that the perturbation correction pQ is unity for all electron energies. In this study, ...

journal_title：Physics in medicine and biology

authors： Zink K,Wulff J

更新日期：2008-03-21 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：:Developments in positron emission tomography (PET) technology have resulted in systems with finer detector elements designed to further improve spatial resolution. However, there is a limit to what extent reducing detector element size will improve spatial resolution in PET. The spatial resolution of PET imaging is li...

journal_title：Physics in medicine and biology

authors： Levin CS,Hoffman EJ

更新日期：1999-03-01 00:00:00

abstract：:Measurements of patient entrance surface dose rate provide valuable data for interpreting results from dose-area product studies on fluoroscopic x-ray equipment. Methods for measurement of entrance surface dose rate with backscatter and incident dose rate without backscatter have been investigated. Entrance surface do...

journal_title：Physics in medicine and biology

authors： Martin CJ

更新日期：1995-05-01 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：:In x-ray based imaging of the breast, contrast between fibroglandular (Fg) tissue and adipose (Ad) tissue is a source of anatomic noise. The goal of this work was to validate by simulation and experiment a mathematical framework for modelling the Fg component of anatomic noise in digital mammograpy (DM) and dual-energ...

journal_title：Physics in medicine and biology

authors： Tanguay J,Lalonde R,Bjarnason TA,Yang CJ

更新日期：2019-10-23 00:00:00

abstract：:A stable cryogel dosimeter was prepared using ferrous benzoic xylenol orange (FBX) in a transparent poly-(vinyl alcohol) (PVA) cryogel matrix. Dose response was evaluated for different numbers of freeze-thaw cycles (FTCs), different concentrations of PVA, and ratios of water/dimethyl sulfoxide. Linear relationships be...

journal_title：Physics in medicine and biology

authors： Eyadeh MM,Farrell TJ,Diamond KR

更新日期：2014-04-07 00:00:00

abstract：:A photoluminescent thermometer, based on the transient emission response of a europium-activated calcium sulphide phosphor, is described in detail. This optical thermometry system has special advantages for temperature measurements in microwave and RF fields and potential application in electromagnetically induced cli...

journal_title：Physics in medicine and biology

authors： Samulski TV,Chopping PT,Haas B

更新日期：1982-01-01 00:00:00

abstract：:Boundary element methods (BEM) are used for forward computation of bioelectromagnetic fields in multi-compartment volume conductor models. Most BEM approaches assume that each compartment is in contact with at most one external compartment. In this work, I present a general surface integral equation and BEM discretiza...

journal_title：Physics in medicine and biology

authors： Stenroos M

更新日期：2016-11-21 00:00:00

abstract：:Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have recently been approved by the Federal Communications Commission for a number of different applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse t...

journal_title：Physics in medicine and biology

authors： Simicevic N

更新日期：2005-11-07 00:00:00

abstract：:The reproducibility of polyacrylamide gel (PAG) dosimetry has been evaluated when used to verify two radiotherapy treatment plans of increasing complexity. The plans investigated were a three-field coplanar arrangement, using the linac jaws for field shaping, and a four-field, conformal, non-coplanar plan using precis...

journal_title：Physics in medicine and biology

authors： Cosgrove VP,Murphy PS,McJury M,Adams EJ,Warrington AP,Leach MO,Webb S

更新日期：2000-05-01 00:00:00

abstract：:We have measured the bulk optical properties of healthy female breast tissues in vivo in the parallel plate, transmission geometry. Fifty-two volunteers were measured. Blood volume and blood oxygen saturation were derived from the optical property data using a novel method that employed a priori spectral information t...

journal_title：Physics in medicine and biology

authors： Durduran T,Choe R,Culver JP,Zubkov L,Holboke MJ,Giammarco J,Chance B,Yodh AG

更新日期：2002-08-21 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：:The rationale for multi-modality imaging is to integrate the strengths of different imaging technologies while reducing the shortcomings of an individual modality. The work presented here proposes a limited-field-of-view (LFOV) SPECT reconstruction technique that can be implemented on a multi-modality MR/SPECT system ...

journal_title：Physics in medicine and biology

authors： Lee KS,Roeck WW,Gullberg GT,Nalcioglu O

更新日期：2011-02-07 00:00:00

abstract：:A method using both patient geometric and dosimetric information was proposed to predict dose-volume histograms (DVHs) of organs at risk (OARs) for a nasopharyngeal cancer (NPC) intensity-modulated radiation therapy (IMRT) plan. A total of 106 nine-field IMRT NPC plans were used in this study. Twenty-six plans were ra...

journal_title：Physics in medicine and biology

authors： Jiao SX,Chen LX,Zhu JH,Wang ML,Liu XW

更新日期：2019-12-05 00:00:00

abstract：:Intensity modulated radiation therapy (IMRT) inverse planning using total-variation (TV) regularization has been proposed to reduce the complexity of fluence maps and facilitate dose delivery. Conventionally, the optimization problem with L-1 norm is solved with quadratic programming (QP), which is time consuming and ...

journal_title：Physics in medicine and biology

authors： Kim H,Suh TS,Lee R,Xing L,Li R

更新日期：2012-07-07 00:00:00

abstract：:For angiography using synchrotron radiation we measured the absorbed dose distribution in inhomogeneous phantoms with thin LiF:Mg, Cu, P, LiF:Mg, Ti thermoluminescent dosimeters (TLDs) in tissue and lung substitutes, and with Mg2SiO4:Tb TLDs in bone substitute for 33.32 keV monoenergetic photons from synchrotron radia...

journal_title：Physics in medicine and biology

authors： Nariyama N,Namito Y,Ban S,Hirayama H

更新日期：2001-03-01 00:00:00