Technical Note: Radiotherapy dose characterization of gel dosimetry using shear wave elasticity imaging.

abstract：:The calibration and quality control of compensators is conventionally performed with an ion chamber in a water-equivalent phantom. In our center, the compensator factor and four off-axis fluence ratios are measured to verify the central axis beam modulation and orientation of the compensator. Here we report the invest...

journal_title：Medical physics

authors： Menon GV,Sloboda RS

更新日期：2003-07-01 00:00:00

abstract：:An electronic scanning-slit technology is under development which involves replacing paired fore and aft slits for scatter rejection with only one fore slit. As the slit scans across the portion of the patient to be imaged, pulsed x-ray exposures produce images of the slit in successive positions, which are digitized ...

journal_title：Medical physics

authors： Plenkovich D,Sorenson JA,Kruger RA

更新日期：1986-03-01 00:00:00

abstract：PURPOSE:With increased use of handheld and tablet display devices for viewing medical images, methods for consistently measuring reflectivity of the devices are needed. In this note, the authors report on the characterization of diffuse reflections for handheld display devices including mobile phones and tablets using ...

journal_title：Medical physics

authors： Liu P,Badano A

更新日期：2014-08-01 00:00:00

abstract：:Respiratory motion can produce misregistration errors between CT and PET images in cardiac PET/CT imaging. The objective of this study was to determine if manual registration of a single-phase end-expiration CT scan to the PET image would eliminate respiratory-induced artifacts. Listmode data from 71 cardiac PET patie...

journal_title：Medical physics

authors： Wells RG

更新日期：2008-07-01 00:00:00

abstract：:We designed a questionnaire to be filled out by the physicist at the time of planning treatment with the aid of a computer in order to assess what was learned during the course of the planning session. We analyzed the results to gauge the impact of the 70 treatment planning sessions conducted during the one month peri...

journal_title：Medical physics

authors： Doppke KP,Goitein M

更新日期：1988-03-01 00:00:00

abstract：:The concept of equivalent uniform dose (EUD) has been suggested as a means to quantitatively consider heterogeneous dose distributions within targets. Tumor cell density/function is typically assumed to be uniform. We herein propose to use 18F-labeled 2-deoxyglucose (FDG) positron emission tomography (PET) tumor imagi...

journal_title：Medical physics

authors： Zhou SM,Wong TZ,Marks LB

更新日期：2004-09-01 00:00:00

abstract：PURPOSE:The authors investigate the impact that incremental increases in the level of detail of patient-specific prior information have on image quality and the convergence behavior of an inversion algorithm in the context of near-field microwave breast imaging. A methodology is presented that uses image quality measur...

journal_title：Medical physics

authors： Kurrant D,Baran A,LoVetri J,Fear E

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:Developed herein is a three-dimensional (3D) flow contrast imaging system leveraging advancements in the extension of laser speckle contrast imaging theories to deep tissues along with our recently developed finite-element diffuse correlation tomography (DCT) reconstruction scheme. This technique, termed speckl...

journal_title：Medical physics

authors： Huang C,Irwin D,Lin Y,Shang Y,He L,Kong W,Luo J,Yu G

更新日期：2015-07-01 00:00:00

abstract：:A proton dose computational algorithm, performing an analytical superposition of infinitely narrow proton beamlets (ASPB) is introduced. The algorithm uses the standard pencil beam technique of laterally distributing the central axis broad beam doses according to the Moliere scattering theory extended to slablike vary...

journal_title：Medical physics

authors： Ciangaru G,Polf JC,Bues M,Smith AR

更新日期：2005-12-01 00:00:00

abstract：PURPOSE:MR thermometry based on the proton resonance frequency shift (PRFS) is the most commonly used method for the monitoring of thermal therapies. As the chemical shift of water protons is temperature dependent, the local temperature variation (relative to an initial baseline) may be calculated from time-dependent p...

journal_title：Medical physics

authors： Viallon M,Terraz S,Roland J,Dumont E,Becker CD,Salomir R

更新日期：2010-04-01 00:00:00

abstract：:We propose a new method based on statistical analysis technique to determine the minimum setup distance of a well chamber used in the calibration of 192Ir high dose rate (HDR). The chamber should be placed at least this distance away from any wall or from the floor in order to mitigate the effect of scatter. Three dif...

journal_title：Medical physics

authors： Chang L,Ho SY,Chui CS,Lee JH,Du YC,Chen T

更新日期：2008-06-01 00:00:00

abstract：:Limiting spatial resolution is a key metric of the quality of magnetic resonance (MR) images, which can provide an indication of the smallest region that can effectively be imaged. In this paper a novel methodology for measuring the limiting spatial resolution of MR images is mathematically analyzed and successfully i...

journal_title：Medical physics

authors： Delakis I,Xanthis C,Kitney RI

更新日期：2009-05-01 00:00:00

abstract：PURPOSE:The aim of this study was to demonstrate a new model for implementing a transit dosimetry system as a means of in vivo dose verification with a water equivalent electronic portal imaging device (WE-EPID) and a conventional treatment planning system (TPS). METHOD AND MATERIALS:A standard amorphous silicon (a-Si...

journal_title：Medical physics

authors： Deshpande S,Blake SJ,Xing A,Metcalfe PE,Holloway LC,Vial P

更新日期：2018-03-01 00:00:00

abstract：:Bioluminescent imaging (BLI) of luciferase-expressing cells in live small animals is a powerful technique for investigating tumor growth, metastasis, and specific biological molecular events. Three-dimensional imaging would greatly enhance applications in biomedicine since light emitting cell populations could be unam...

journal_title：Medical physics

authors： Slavine NV,Lewis MA,Richer E,Antich PP

更新日期：2006-01-01 00:00:00

abstract：:An in vitro radiographic technique which uses saline/iodine displacement has been developed to study the thickness of bone-equivalent and soft-tissue-equivalent materials within atherosclerotic plaques in arterial specimens which have been cut open longitudinally and laid flat. Results concerning the optimization of t...

journal_title：Medical physics

authors： Moreau M,Holdsworth DW,Fenster A

更新日期：1997-01-01 00:00:00

abstract：:In the last 30 years, thousands of basic or clinical studies have been devoted to atherosclerosis or to the problem of restenosis after angioplasty. In these studies, axial stresses in the vessel wall have received practically no attention, contrary to circumferential stress and purely biological aspects. Based on a r...

journal_title：Medical physics

authors： Doriot PA,Dorsaz PA

更新日期：2005-02-01 00:00:00

abstract：:Using stable materials capable of mimicking any soft tissues of the human body--quantitatively with respect to speed of sound, density, and attenuation coefficient and semiquantitatively with respect to scatter--we have constructed a torso section phantom containing simulated bowel gas, kidney, kidney fat pad, liver, ...

journal_title：Medical physics

authors： Madsen EL,Zagzebski JA,Ghilardi-Netto T

更新日期：1980-01-01 00:00:00

abstract：:A method for finding optimal primary fluence profiles for multiple field external beam radiation therapy techniques has been developed using a radiobiologically based objective function that quantifies the probability of achieving complication-free tumor control, P+. The objective function P+ has the valuable property...

journal_title：Medical physics

authors： Södertröm S,Brahme A

更新日期：1993-07-01 00:00:00

abstract：:The dose distribution for an ovoid with a new tungsten shielding design was determined using Monte Carlo simulation. Standard Cesium-137 tube sources, tungsten shielding, and aluminum ovoid applicator were each modeled as a collection of solid objects. Dose was calculated in planes above, below, in front of, and on th...

journal_title：Medical physics

authors： Weeks KJ

更新日期：1998-12-01 00:00:00

abstract：:The computational aspects of the design of an optical distance indicator (ODI) for use with a radiation therapy accelerator are discussed. The specifics of the optical and mechanical design of an ODI for use with a superconducting cyclotron used for fast neutron therapy are presented. ...

journal_title：Medical physics

authors： Maughan RL

更新日期：1999-02-01 00:00:00

abstract：PURPOSE:To design a fast Winston Lutz (fWL) algorithm for accurate analysis of radiation isocenter from images without edge detection or center of mass calculations. METHODS:An algorithm has been developed to implement the Winston Lutz test for mechanical/ radiation isocenter agreement using an electronic portal imagi...

journal_title：Medical physics

authors： Winey B,Sharp G,Bussière M

更新日期：2011-01-01 00:00:00

abstract：:A new type of radiographic film, EDR (extended dose range) film, has been recently become available for film dosimetry. It is particularly attractive for composite isodose verification of intensity modulated radiation therapy because of its low sensitivity relative to the more common Kodak XV film. For XV film, the re...

journal_title：Medical physics

authors： Zhu XR,Yoo S,Jursinic PA,Grimm DF,Lopez F,Rownd JJ,Gillin MT

更新日期：2003-05-01 00:00:00

abstract：PURPOSE:To develop a pencil beam dose calculation algorithm for scanned proton beams that improves modeling of scatter events. METHODS:Our pencil beam algorithm (PBA) was developed for calculating dose from monoenergetic, parallel proton beams in homogeneous media. Fermi-Eyges theory was implemented for pencil beam tr...

journal_title：Medical physics

authors： Chapman J,Fontenot J,Newhauser W,Hogstrom K

更新日期：2012-06-01 00:00:00

abstract：:Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Sev...

journal_title：Medical physics

authors： Tutar IB,Managuli R,Shamdasani V,Cho PS,Pathak SD,Kim Y

更新日期：2003-12-01 00:00:00

abstract：PURPOSE:This work describes the performance characterization of a cone-beam CT-guided radiosurgery device, the Gamma Knife® Icon™. METHODS:The performance tests have been categorized into: (a) image quality and mechanical integrity; (b) image coregistration fidelity; (c) adaptive treatment delivery quality; (d) high d...

journal_title：Medical physics

authors： Sarfehnia A,Ruschin M,Chugh B,Yeboah C,Becker N,Cho YB,Lee Y

更新日期：2018-06-29 00:00:00

abstract：:The authors describe a method for directly digitizing optical images with a photostimulable phosphor (PSP) system. A PSP plate is initially charged with an exposure to a uniform x-ray field, and is then exposed to an optical image which discharges the plate in relation to the amount of incident light. Two applications...

journal_title：Medical physics

authors： Dobbins JT 3rd,Chotas HG,Benveniste H

更新日期：1992-07-01 00:00:00

abstract：PURPOSE:Photon counting arrays (PCAs), capable of measuring the spectral information of individual x-ray photons and recording that information digitally, provide a number of advantages compared to conventional, energy-integrating active matrix flat-panel imagers - such as reducing the undesirable effects of electronic...

journal_title：Medical physics

authors： Liang AK,Koniczek M,Antonuk LE,El-Mohri Y,Zhao Q

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:To apply the dual ionization chamber method for mixed radiation fields to an accurate comparison of the secondary neutron dose arising from the use of a tungsten alloy multileaf collimator (MLC) as opposed to a brass collimator system for defining the shape of a therapeutic proton field. METHODS:Hydrogenous an...

journal_title：Medical physics

authors： Diffenderfer ES,Ainsley CG,Kirk ML,McDonough JE,Maughan RL

更新日期：2011-11-01 00:00:00

abstract：:A simple modification is presented for two commercially available hyperthermia applicators which dramatically improves the regulation and dynamic control of the temperature at the bolus/tissue interface. This alteration requires the addition of a variable speed pump, bubble trap, simple heat exchanger, and a few minor...

journal_title：Medical physics

authors： Diederich CJ,Stauffer PR,Bozzo D

更新日期：1994-09-01 00:00:00

abstract：PURPOSE:Accurate deformable image registration is necessary for longitudinal studies. The error associated with commercial systems has been evaluated using computed tomography (CT). Several in-house algorithms have been evaluated for use with magnetic resonance imaging (MRI), but there is still relatively little inform...

journal_title：Medical physics

authors： Ger RB,Yang J,Ding Y,Jacobsen MC,Fuller CD,Howell RM,Li H,Jason Stafford R,Zhou S,Court LE

更新日期：2017-10-01 00:00:00