Mammogram synthesis using a three-dimensional simulation. III. Modeling and evaluation of the breast ductal network.

abstract：PURPOSE:Accurate segmentation of lung and infection in COVID-19 computed tomography (CT) scans plays an important role in the quantitative management of patients. Most of the existing studies are based on large and private annotated datasets that are impractical to obtain from a single institution, especially when radi...

journal_title：Medical physics

authors： Ma J,Wang Y,An X,Ge C,Yu Z,Chen J,Zhu Q,Dong G,He J,He Z,Cao T,Zhu Y,Nie Z,Yang X

更新日期：2020-12-23 00:00:00

abstract：PURPOSE:Periodic MV∕KV radiographs taken during volumetric modulated arc therapy (VMAT) for hypofractionated treatment provide guidance in intrafractional motion management. The choice of imaging frequency and timing are key components in delivering the desired dose while reducing associated overhead such as imaging do...

journal_title：Medical physics

authors： Zhang P,Hunt M,Happersett L,Cox B,Mageras G

更新日期：2012-09-01 00:00:00

abstract：:Accurate targeting is important in intensity-modulated radiation therapy (IMRT). The positional uncertainties of structures with respect to the external beams arise in part from random organ motion and patient setup errors. While it is important to improve immobilization and reduce the influence of organ motion, the r...

journal_title：Medical physics

authors： Li JG,Xing L

更新日期：2000-07-01 00:00:00

abstract：PURPOSE:Radiosensitizer enhanced radiotherapy provides the possibility of improved treatment outcomes by preferentially increasing the effectiveness of radiation within the tumor. Proton therapy offers improved sparing of tissue distal of the tumor along the beam path and reduced integral dose compared to conventional ...

journal_title：Medical physics

authors： Peukert D,Kempson I,Douglass M,Bezak E

更新日期：2020-02-01 00:00:00

abstract：:We designed a novel force/torque moment transducer with six degrees of freedom. This new sensor is used for measuring the forces and torque moments exerted by static magnetic resonance imaging (MRI) fields on various medical implants, instruments, and ballistic shell fragments. To determine the location of strongest e...

journal_title：Medical physics

authors： Planert J,Modler H,Vosshenrich R

更新日期：1996-06-01 00:00:00

abstract：:An overall practical dosimetric study of a 10-MV photon beam produced by a Varian Clinac-18 linear accelerator is presented. In particular measurements were made to provide data which could be utilized in computerized dosage calculations using the concept of dividing the radiation beam into primary and scatter compone...

journal_title：Medical physics

authors： Van Dyk J

更新日期：1977-03-01 00:00:00

abstract：PURPOSE:Ultrasound-induced mild hyperthermia has advantages for noninvasive, localized and controlled drug delivery. In this study, a tissue-mimicking agarose-based phantom with a thermally sensitive indicator was developed for studying the spatial drug delivery profile using ultrasound-induced mild hyperthermia. METH...

journal_title：Medical physics

authors： Lai CY,Kruse D,Seo JW,Kheirolomoom A,Ferrara KW

更新日期：2013-08-01 00:00:00

abstract：:This paper examines statistical errors in the measurement of arterial stenoses by digital videodensitometry. Images of vessel phantoms were acquired using digital subtraction angiographic techniques with low concentrations of an iodine contrast medium and low levels of x-ray exposure. Effects of the spatial and tempor...

journal_title：Medical physics

authors： Wright GA,Taylor KW,Rowlands JA

更新日期：1985-11-01 00:00:00

abstract：PURPOSE:To improve image quality and reduce imaging dose in CBCT for radiation therapy applications and to realize near real-time image reconstruction based on use of a fast convergence iterative algorithm and acceleration by multi-GPUs. METHODS:An iterative image reconstruction that sought to minimize a weighted leas...

journal_title：Medical physics

authors： Xu Q,Yang D,Tan J,Anastasio M

更新日期：2012-06-01 00:00:00

abstract：:A single-field rotational total skin electron irradiation technique has recently been developed at the McGill University for treatment of skin malignancies. The dose received by a given surface point during rotation in a uniform large electron field depends on the radius of rotation of the surface point, on the local ...

journal_title：Medical physics

authors： Pla C,Heese R,Pla M,Podgorsak EB

更新日期：1984-07-01 00:00:00

abstract：PURPOSE:Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in co...

journal_title：Medical physics

authors： Andreassen B,Strååt SJ,Holmberg R,Näfstadius P,Brahme A

更新日期：2011-08-01 00:00:00

abstract：PURPOSE:High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly (192)Ir with an air KERMA strength range between 20,000 and 40,000 U, where 1 U = 1 μGy m(2)/h in a...

journal_title：Medical physics

authors： Espinoza A,Beeksma B,Petasecca M,Fuduli I,Porumb C,Cutajar D,Corde S,Jackson M,Lerch ML,Rosenfeld AB

更新日期：2013-11-01 00:00:00

abstract：:CEA TVS film is a therapy verification film that has been recently introduced in the North American market. This film features linear characteristic curves for photon energies from 137Cs to 18 MV as reported by Cheng and Das [Med. Phys. 23, 1225 (1996)]. In Saskatoon, TVS film was investigated for its application in t...

journal_title：Medical physics

authors： Cadman P

更新日期：1998-08-01 00:00:00

abstract：PURPOSE:This report describes upgrades and performance characterization of an experimental benchtop cone-beam x-ray fluorescence computed tomography (XFCT) system capable of determining the spatial distribution and concentration of metal probes such as gold nanoparticles (GNPs). Specifically, a high-power (~3 kW) indus...

journal_title：Medical physics

authors： Manohar N,Reynoso FJ,Cho SH

更新日期：2018-10-01 00:00:00

abstract：:A method for the in vivo determination of the isocenter dose, Diso, and mid-plane dose, Dm, using the transmitted signal St measured by 25 central pixels of an aSi-based EPID is here reported. The method has been applied to check the conformal radiotherapy of pelvic tumors and supplies accurate in vivo dosimetry avoid...

journal_title：Medical physics

authors： Piermattei A,Fidanzio A,Stimato G,Azario L,Grimaldi L,D'Onofrio G,Cilla S,Balducci M,Gambacorta MA,Di Napoli N,Cellini N

更新日期：2006-11-01 00:00:00

abstract：:Anatomy-based positron emission tomography (PET) image enhancement techniques have been shown to have the potential for improving PET image quality. However, these techniques assume an accurate alignment between the anatomical and the functional images, which is not always valid when imaging the chest due to respirato...

journal_title：Medical physics

authors： Qiao F,Pan T,Clark JW Jr,Mawlawi O

更新日期：2007-12-01 00:00:00

abstract：PURPOSE:The determination of absorbed dose to water from external beam radiotherapy using radiation detectors is currently rooted in calibration protocols that do not account for modulations encountered in patient-specific deliveries. Detector response in composite clinical fields has not been extensively studied due t...

journal_title：Medical physics

authors： Desai VK,Labby ZE,Hyun MA,DeWerd LA,Culberson WS

更新日期：2019-02-01 00:00:00

abstract：:Volumetric modulated arc therapy (VMAT) has recently been used to improve the dose distribution and efficiency of treatment delivery over the standard intensity-modulated radiotherapy (IMRT) technique. This study compares the dosimetry between RapidArc plan and standard IMRT plan for head and neck cancer. Three head a...

journal_title：Medical physics

authors： Jiang R,Fleck A,Schaly B,Charland P,Zhan L,Alliet K,Rachakonda R,Osei E

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:To validate GPUMCD, a new package for fast Monte Carlo dose calculations based on the GPU (graphics processing unit), as a tool for low-energy single seed brachytherapy dosimetry for specific seed models. As the currently accepted method of dose calculation in low-energy brachytherapy computations relies on sev...

journal_title：Medical physics

authors： Hissoiny S,Ozell B,Després P,Carrier JF

更新日期：2011-07-01 00:00:00

abstract：PURPOSE:The absolute dose rate of the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter. The calorimetry results were compared to measurements from the existing free-air chamber, to provide a robust determination of the absolute dose in the synchrotron beam and p...

journal_title：Medical physics

authors： Harty PD,Lye JE,Ramanathan G,Butler DJ,Hall CJ,Stevenson AW,Johnston PN

更新日期：2014-05-01 00:00:00

abstract：:The resolution has been evaluated for an experimental x-ray image intensifier employing three microchannel plates (MCPs) as the photon absorber and electron multipliers. The line spread function (LSF) was measured and used for determination of the modulation transfer function (MTF). The MTF was found to be independent...

journal_title：Medical physics

authors： Gould RG

更新日期：1978-01-01 00:00:00

abstract：PURPOSE:To assess the temporal and spatial accuracy of the GateCT™ system (VisionRT, London, UK), a recently released respiratory tracking system for 4DCT, under both ideal and nonideal respiratory conditions. METHODS:Three experiments were performed by benchmarking and comparing its results with the ground-truth inpu...

journal_title：Medical physics

authors： Kauweloa KI,Ruan D,Park JC,Sandhu A,Kim GY,Pawlicki T,Watkins WT,Song B,Song WY

更新日期：2012-01-01 00:00:00

abstract：:Stereotactic X-ray mammography (SM) and ultrasound (US) guidance are both commonly used for breast biopsy. While SM provides three-dimensional (3D) targeting information and US provides real-time guidance, both have limitations. SM is a long and uncomfortable procedure and the US guided procedure is inherently two dim...

journal_title：Medical physics

authors： Surry KJ,Mills GR,Bevan K,Downey DB,Fenster A

更新日期：2007-11-01 00:00:00

abstract：:The modulation transfer function (MTF) of a screen-film system can be measured by two methods, i.e., a slit method with Fourier transform on the line spread function and a square-wave response function (SWRF) method. However, it is still uncertain whether MTFs obtained by the two methods are identical. In this study, ...

journal_title：Medical physics

authors： Morishita J,Doi K,Bollen R,Bunch PC,Hoeschen D,Sirand-rey G,Sukenobu Y

更新日期：1995-02-01 00:00:00

abstract：PURPOSE:The purpose of this work is twofold: First, to characterize the artifacts occurring in helical 4D-CT imaging; second, to propose a method that can automatically identify the artifacts in 4D-CT images. The authors have designed a process that can automatically identify the artifacts in 4D-CT images, which may be...

journal_title：Medical physics

authors： Han D,Bayouth J,Bhatia S,Sonka M,Wu X

更新日期：2011-04-01 00:00:00

abstract：:Depth dose characteristics of 24-MV beams from a medical linear accelerator at various SSDs have been measured. The dose buildup, percent depth dose (PDD), and output were measured using ionization chambers and a diode detector under full scatter. Surface dose ranged from 8% to 51% depending upon the collimator settin...

journal_title：Medical physics

authors： Jani SK,Pennington EC

更新日期：1991-03-01 00:00:00

abstract：:In the present investigation, the necessary tests for implementing a quality assurance program for a commercial treatment planning system (TPS), recently installed at Sao Paulo University School of Medicine Clinicas Hospital-Brazil, was established and performed in accordance with the new IAEA publication TRS 430, and...

journal_title：Medical physics

authors： Camargo PR,Rodrigues LN,Furnari L,Rubo RA

更新日期：2007-07-01 00:00:00

abstract：PURPOSE:The possible clinical applications which can be performed using a newly developed detector depend on the detector's characteristic performance in a number of metrics including the dynamic range, resolution, uniformity, and stability. The authors have evaluated a prototype energy resolved fast photon counting x-...

journal_title：Medical physics

authors： Cho HM,Barber WC,Ding H,Iwanczyk JS,Molloi S

更新日期：2014-09-01 00:00:00

abstract：PURPOSE:Stereotactic body radiation therapy (SBRT) is a radiotherapy technique which uses high dose fractions with multiple coplanar and noncoplanar beams. Due to the large fractional doses, treatments are typically protracted and there are more fields than in conventional radiation treatment schemes. The effect of tem...

journal_title：Medical physics

authors： Schmitt JD,Warren GW,Wang IZ

更新日期：2012-06-01 00:00:00

abstract：:The gamma index is a tool that compares a dose distribution with a reference distribution by combining dose-difference and distance-to-agreement criteria. It has been widely used for ten years despite its high computational cost. This cost is due to both a search process for each reference point and the necessity to r...

journal_title：Medical physics

authors： Blanpain B,Mercier D

更新日期：2009-03-01 00:00:00