A modified lead attenuation method to determine the fast neutron sensitivity kU of a photon dosemeter.

abstract：:Measurements of lung nodule volume with multi-detector computed tomography (MDCT) have been shown to be more accurate and precise compared to conventional lower dimensional measurements. Quantifying the size of lesions is potentially more difficult when the object-to-background contrast is low as with lesions in the l...

journal_title：Physics in medicine and biology

authors： Li Q,Gavrielides MA,Zeng R,Myers KJ,Sahiner B,Petrick N

更新日期：2015-01-21 00:00:00

abstract：:Most solid-state detectors, including 3D dosimeters, show lower signal in the Bragg peak than expected, a process termed quenching. The purpose of this study was to investigate how variation in chemical composition of a recently developed radiochromic, silicone-based 3D dosimeter influences the observed quenching in p...

journal_title：Physics in medicine and biology

authors： Høye EM,Skyt PS,Balling P,Muren LP,Taasti VT,Swakoń J,Mierzwińska G,Rydygier M,Bassler N,Petersen JB

更新日期：2017-02-21 00:00:00

abstract：:The measurement of beam data for dynamic wedge dosimetry requires the integration of radiation dose at points across the radiation field during the dose delivery. The different measurement techniques required when using a linear diode array to measure beam profiles and when using ionization chambers to measure depth d...

journal_title：Physics in medicine and biology

authors： Bidmead AM,Garton AJ,Childs PJ

更新日期：1995-03-01 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：:Motion-adaptive radiotherapy aims to deliver a conformal dose to the target tumour with minimal normal tissue exposure by compensating for tumour motion in real time. The prediction as well as the gating of respiratory motion have received much attention over the last two decades for reducing the targeting error of th...

journal_title：Physics in medicine and biology

authors： Bukhari W,Hong SM

更新日期：2015-01-07 00:00:00

abstract：:Skin toxicity has been reported for IMRT of head and neck cancer. The purpose of this study was to investigate the dose in the build-up region delivered by a 6 MV treatment plan for which important skin toxicity was observed. We also investigated if the different designs of the treatment head of an Elekta and a Varian...

journal_title：Physics in medicine and biology

authors： Paelinck L,De Wagter C,Van Esch A,Duthoy W,Depuydt T,De Neve W

更新日期：2005-02-07 00:00:00

abstract：:In the IAEA-AAPM dosimetry formalism, detector measurements in general nonstandard conditions are corrected using the factor k(f(clin),f(msr))(Q(clin),Q(msr)). This factor needs to be evaluated on a case-by-case basis which is difficult to accomplish in practice. The present paper aims to provide a method that allows ...

journal_title：Physics in medicine and biology

authors： Kamio Y,Bouchard H

更新日期：2014-09-07 00:00:00

abstract：:The purpose of this work was to study and quantify the differences in dose distributions computed with some of the newest dose calculation algorithms available in commercial planning systems. The study was done for clinical cases originally calculated with pencil beam convolution (PBC) where large density inhomogeneit...

journal_title：Physics in medicine and biology

authors： Hasenbalg F,Neuenschwander H,Mini R,Born EJ

更新日期：2007-07-07 00:00:00

abstract：:The authors have developed an apparatus able to generate ID intensity-modulated beams, using only one moving absorber within the irradiation field. A procedure for deriving optimized absorber-speed profiles in order to produce the desired fluence/dose profiles has been suggested. Experimental tests show that the syste...

journal_title：Physics in medicine and biology

authors： Fiorino C,Lev A,Fusca M,Cattaneo GM,Rudello F,Calandrino R

更新日期：1995-02-01 00:00:00

abstract：:A method is described which offers an alternative to conventional Fourier phase/amplitude imaging for analysing representative LV cycles obtained from first-pass cardiac studies. The method involves applying factor analysis to the data and producing functional images of the first two factor loadings after polar transf...

journal_title：Physics in medicine and biology

authors： Houston AS,Elliott AT,Stone DL

更新日期：1982-10-01 00:00:00

abstract：:Avoiding toxicities in radiotherapy requires the knowledge of tolerable organ doses. For new, experimental fractionation schemes (e.g. hypofractionation) these are typically derived from traditional schedules using the biologically effective dose (BED) model. In this report we investigate the difficulties of establish...

journal_title：Physics in medicine and biology

authors： Perkó Z,Bortfeld T,Hong T,Wolfgang J,Unkelbach J

更新日期：2018-02-05 00:00:00

abstract：:A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is incorporated into a grow...

journal_title：Physics in medicine and biology

authors： Warman JM,de Haas MP,Luthjens LH

更新日期：2009-05-21 00:00:00

abstract：:Over the course of radiation therapy, a patient's anatomy may change substantially. The relatively recent addition of frequent in-room imaging to assist with patient localization has provided a database of images that may be used to recalculate dose distributions for adaptive radiotherapy purposes. The TomoTherapy Hi-...

journal_title：Physics in medicine and biology

authors： Pukala J,Meeks SL,Bova FJ,Langen KM

更新日期：2011-12-21 00:00:00

abstract：:Using Cherenkov radiation in positron emission tomography (PET) has the potential to improve the time of flight (TOF) resolution and reduce the cost of detectors. In previous studies promising TOF results were achieved when lead fluoride (PbF2) crystals were used instead of a scintillator. In this work, a whole-body P...

journal_title：Physics in medicine and biology

authors： Consuegra D,Korpar S,Križan P,Pestotnik R,Razdevšek G,Dolenec R

更新日期：2020-03-06 00:00:00

abstract：:During image-guided cancer radiation treatment, three-dimensional (3D) tumor volumetric information is important for treatment success. However, it is typically not feasible to image a patient's 3D tumor continuously in real time during treatment due to concern over excessive patient radiation dose. We present a new i...

journal_title：Physics in medicine and biology

authors： Mao S,Wu H,Sandison G,Fang S

更新日期：2017-02-21 00:00:00

abstract：:It has been reported that acoustic waves are generated when a high-energy pulsed proton beam is deposited in a small volume within tissue. One possible application of proton-induced acoustics is to get real-time feedback for intra-treatment adjustments by monitoring such acoustic waves. A high spatial resolution in ul...

journal_title：Physics in medicine and biology

authors： Kipergil EA,Erkol H,Kaya S,Gulsen G,Unlu MB

更新日期：2017-06-21 00:00:00

abstract：:Cylindrical homogenous phantoms for magnetic resonance (MR) elastography in biomedical research provide one way to validate an imaging systems performance, but the simplified geometry and boundary conditions can cloak complexity arising at tissue interfaces. In an effort to develop a more realistic gel tissue phantom ...

journal_title：Physics in medicine and biology

authors： Schwartz BL,Yin Z,Magin RL

更新日期：2016-09-21 00:00:00

abstract：:The automatic calibration in Fourier-domain optical coherence tomography (FD-OCT) systems allows for high resolution imaging with precise depth ranging functionality in many complex imaging scenarios, such as microsurgery. However, the accuracy and speed of the existing automatic schemes are limited due to the functio...

journal_title：Physics in medicine and biology

authors： Ratheesh KM,Seah LK,Murukeshan VM

更新日期：2016-11-07 00:00:00

abstract：:Using Monte Carlo simulation of 99Tcm single-photon-emission computed tomography (SPECT), we investigate the effects of tissue-background activity, tumour location, patient size, uncertainty of energy windows, and definition of tumour region on the accuracy of quantification. The dual-energy-window method of correctio...

journal_title：Physics in medicine and biology

authors： Luo JQ,Koral KF,Ljungberg M,Floyd CE Jr,Jaszczak RJ

更新日期：1995-01-01 00:00:00

abstract：:A function called Gx(L) was introduced by the International Commission on Radiation Units and Measurements (ICRU) Report-87 to facilitate measurement of cumulative dose for CT scans within long phantoms as recommended by the American Association of Physicists in Medicine (AAPM) TG-111. The Gx(L) function is equal to t...

journal_title：Physics in medicine and biology

authors： Abuhaimed A,Martin CJ,Sankaralingam M,Gentle DJ

更新日期：2015-07-21 00:00:00

abstract：:Compton scatter poses a significant threat to volumetric x-ray computed tomography, bringing cupping and streak artefacts thus impacting qualitative and quantitative imaging procedures. To perform appropriate scatter compensation, it is necessary to estimate the magnitude and spatial distribution of x-ray scatter. The...

journal_title：Physics in medicine and biology

authors： Akbarzadeh A,Ay MR,Ghadiri H,Sarkar S,Zaidi H

更新日期：2010-04-21 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：:Ultrasound in the low megahertz frequency range is used by physiotherapists to treat a variety of conditions. The treatments reduce swelling, reduce pain and increase movement at joints. Ultrasound is now also beginning to be used to treat malignant tumours. The tumours are heated to temperatures between 42 degrees an...

journal_title：Physics in medicine and biology

authors： Quan KM,Shiran M,Watmough DJ

更新日期：1989-11-01 00:00:00

abstract：:We developed an anatomy-guided 4D closed-form algorithm to directly reconstruct parametric images from projection data for (nearly) irreversible tracers. Conventional methods consist of individually reconstructing 2D/3D PET data, followed by graphical analysis on the sequence of reconstructed image frames. The propose...

journal_title：Physics in medicine and biology

authors： Tang J,Kuwabara H,Wong DF,Rahmim A

更新日期：2010-08-07 00:00:00

abstract：:Dynamic SPECT is a relatively new technique that may potentially benefit many imaging applications. Though similar to dynamic PET, the accuracy and precision of dynamic SPECT parameter estimates are degraded by factors that differ from those encountered in PET. In this work we formulate a methodology for analytically ...

journal_title：Physics in medicine and biology

authors： Kadrmas DJ,DiBella EV,Huesman RH,Gullberg GT

更新日期：1999-08-01 00:00:00

abstract：:Positron emission tomography is one of the most mature techniques for monitoring the particles range in hadron therapy, aiming to reduce treatment uncertainties and therefore the extent of safety margins in the treatment plan. In-beam PET monitoring has been already performed using inter-spill and post-irradiation dat...

journal_title：Physics in medicine and biology

authors： Kostara E,Sportelli G,Belcari N,Camarlinghi N,Cerello P,Del Guerra A,Ferrero V,Fiorina E,Giraudo G,Morrocchi M,Pennazio F,Pullia M,Rivetti A,Rolo MD,Rosso V,Wheadon R,Bisogni MG

更新日期：2019-01-21 00:00:00

abstract：:A pencil beam model for the calculation of the lateral scattering in water of protons for any therapeutic energy and depth is presented. It is based on the full Molière theory, taking into account the energy loss and the effects of mixtures and compounds. Concerning the electromagnetic part, the model has no free para...

journal_title：Physics in medicine and biology

authors： Bellinzona EV,Ciocca M,Embriaco A,Ferrari A,Fontana A,Mairani A,Parodi K,Rotondi A,Sala P,Tessonnier T

更新日期：2016-02-21 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：BACKGROUND:During transcranial electrical stimulation (tES), including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), current density concentration around the electrode edges that is predicted by simplistic skin models does not match experimental observations of ...

journal_title：Physics in medicine and biology

authors： Khadka N,Bikson M

更新日期：2020-09-11 00:00:00

abstract：:Proton therapy with active scanning beam delivery has significant advantages compared to conventional radiotherapy. However, so far only static targets have been treated in this way, since moving targets potentially lead to interplay effects. For 4D treatment planning, information on the target motion is needed to cal...

journal_title：Physics in medicine and biology

authors： Zhang Y,Boye D,Tanner C,Lomax AJ,Knopf A

更新日期：2012-04-07 00:00:00