Onboard functional and molecular imaging: a design investigation for robotic multipinhole SPECT.

abstract：:This paper outlines a method for determining proper removal-diffusion parameters to be used in removal-diffusion theory calculations for the purpose of BNCT treatment planning. Additionally, this paper demonstrates that, given the proper choice of removal-diffusion parameters, removal-diffusion theory may provide an a...

journal_title：Medical physics

authors： Albertson BJ,Blue TE,Niemkiewicz J

更新日期：2001-09-01 00:00:00

abstract：PURPOSE:To achieve more translatable preclinical research results, small animal irradiation needs to more closely simulate human radiotherapy. Although the clinical gold standard is intensity-modulated radiation therapy (IMRT), the direct translation of this method for small animals is impractical. In this study we des...

journal_title：Medical physics

authors： Woods K,Nguyen D,Neph R,Ruan D,O'Connor D,Sheng K

更新日期：2019-12-01 00:00:00

abstract：:Optimal visualization of moving structures such as the heart and coronary arteries using digital radiographic imaging systems is a difficult problem that can involve tradeoffs between temporal, spatial, and density resolution. The motion dependence of four angiographic measures of vessel dimensions is given and demons...

journal_title：Medical physics

authors： Parker DL,Clayton PD,Gustafson DE

更新日期：1985-11-01 00:00:00

abstract：PURPOSE:The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD). METHODS:Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and exp...

journal_title：Medical physics

authors： Wang X,Duan J,Du Y,Shen N,He B,Yuan H

更新日期：2013-08-01 00:00:00

abstract：PURPOSE:4d cone-beam computed tomography (CBCT) scans are usually reconstructed by extracting the motion information from the 2d projections or an external surrogate signal, and binning the individual projections into multiple respiratory phases. In this "after-the-fact" binning approach, however, projections are uneve...

journal_title：Medical physics

authors： Fast MF,Wisotzky E,Oelfke U,Nill S

更新日期：2013-09-01 00:00:00

abstract：PURPOSE:Optoacoustic imaging enables mapping the optical absorption of biological tissue using optical excitation and acoustic detection. Although most image-reconstruction algorithms are based on the assumption of a detector with an isotropic sensitivity, the geometry of the detector often leads to a response with spa...

journal_title：Medical physics

authors： Rosenthal A,Ntziachristos V,Razansky D

更新日期：2011-07-01 00:00:00

abstract：:Four different expressions, derived from the diffusion theory or the random walk model, were used to fit time-resolved reflectance data for the evaluation of tissue optical properties. The experimental reflectance curves were obtained from phantoms of known optical parameters (absorption and transport scattering coeff...

journal_title：Medical physics

authors： Cubeddu R,Pifferi A,Taroni P,Torricelli A,Valentini G

更新日期：1996-09-01 00:00:00

abstract：PURPOSE:MR-guided radiation therapy (RT) offers unparalleled soft tissue contrast for localization and target tracking. However, MRI distortions may be detrimental to high precision RT. This work characterizes the gradient nonlinearity (GNL) and total distortions over the first year of clinical operation of a 0.35T MR-...

journal_title：Medical physics

authors： Nejad-Davarani SP,Kim JP,Du D,Glide-Hurst C

更新日期：2019-05-01 00:00:00

abstract：:Although x-ray computed tomography (CT) has been in clinical use for over 3 decades, spectral optimization has not been a topic of great concern; high voltages around 120 kV have been in use since the beginning of CT. It is the purpose of this study to analyze, in a rigorous manner, the energies at which the patient d...

journal_title：Medical physics

authors： Kalender WA,Deak P,Kellermeier M,van Straten M,Vollmar SV

更新日期：2009-03-01 00:00:00

abstract：PURPOSE:To investigate whether building a knowledge-based planning (KBP) model with prostate bed plans constructed from constrained hierarchical optimization (CHO) would result in more efficient model construction with more consistent output than a model built using plans from a traditional, trial-and-error-based optim...

journal_title：Medical physics

authors： Lin YH,Hong LX,Hunt MA,Berry SL

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:We present a simple, practical framework for truly 4D lung IMRT planning based on a weighted individual-phase optimization paradigm. This strategy is specifically developed for use in real-time tumor tracking delivery systems so as to utilize respiratory motion as an additional degree of freedom rather than a c...

journal_title：Medical physics

authors： Tachibana H,Cheung Y,Jain S,Sawant A

更新日期：2012-06-01 00:00:00

abstract：:This study concerns the accuracy and precision of the IAEA/WHO LiF TLD system used in intercomparison by mail of absorbed doses from 60Co gamma-radiation and 4-25 MV x rays. The system employs 160 mg LiF powder in polystyrene capsules, which are placed at 5 or 7 cm depth in water and irradiated to doses close to 200 r...

journal_title：Medical physics

authors： Bjärngard BE,Kase KR,Rudén BI,Biggs PJ,Boyer AL,Johansson KA

更新日期：1980-09-01 00:00:00

abstract：:Noise power spectrum (NPS) and detective quantum efficiency (DQE) for metal-plate/film portal detectors are reported for the Co-60 and Linac 10 MV spectra. The detectors consist of a double-emulsion portal film secured between plates of aluminum, copper, brass, or lead. The NPS was found to be independent of the detec...

journal_title：Medical physics

authors： Falco T,Fallone BG

更新日期：1998-12-01 00:00:00

abstract：PURPOSE:To evaluate the availability and performance of pencil beam algorithm for fast neutrons radiotherapy dose calculations and to achieve improvements in universality, speed and inhomogeneities corrections. METHODS:Pencil beam (PB) method uses integration of dose kernel cross field size to estimate dose distributi...

journal_title：Medical physics

authors： Moiseev A,Klimanov V

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To investigate the geometry dependence of the detector response function (DRF) of three commonly used scanning ionization chambers and its impact on a convolution-based method to address the volume averaging effect (VAE). METHODS:A convolution-based approach has been proposed recently to address the ionization...

journal_title：Medical physics

authors： Barraclough B,Li JG,Lebron S,Fan Q,Liu C,Yan G

更新日期：2016-05-01 00:00:00

abstract：PURPOSE:To formulate convex planning objectives of treatment plan multicriteria optimization with explicit relationships to the dose-volume histogram (DVH) statistics used in plan quality evaluation. METHODS:Conventional planning objectives are designed to minimize the violation of DVH statistics thresholds using pena...

journal_title：Medical physics

authors： Engberg L,Forsgren A,Eriksson K,Hårdemark B

更新日期：2017-06-01 00:00:00

abstract：:Two recently developed A 150 plastic-equivalent gas mixtures have been tested for suitability in proportional counter applications. Methane- and propane-based "tissue-equivalent" gases were also included for comparison purposes. Event-size weighted dose distributions were measured in a 14.8-MeV neutron beam. Resolutio...

journal_title：Medical physics

authors： DeLuca PM Jr,Schell MC,Pearson DW,Higgins PD,Attix FH

更新日期：1984-07-01 00:00:00

abstract：:Age-related macular degeneration (AMD) is a leading cause for vision loss for people over the age of 65 in the United States and a major health problem worldwide. Research for new treatments of the wet form of the disease using kilovoltage stereotactic radiosurgery is currently underway at Oraya Therapeutics, Inc. In ...

journal_title：Medical physics

authors： Hanlon J,Lee C,Chell E,Gertner M,Hansen S,Howell RW,Bolch WE

更新日期：2009-08-01 00:00:00

abstract：PURPOSE:The liver segments divided by Couinaud classification method are used to understand the functional anatomy of liver, which is significant in hepatic resection surgery. In Couinaud classification method, each third-order branch of the portal vein (PV) defines the supplied territory of a corresponding liver segme...

journal_title：Medical physics

authors： Wu C,Fu T,Gao Y,Liu Y,Fan J,Ai D,Song H,Yang J

更新日期：2021-02-02 00:00:00

abstract：PURPOSE:The purpose of the paper was to use a virtual phantom to identify a set of radiomic features from T1-weighted and T2-weighted magnetic resonance imaging (MRI) of the brain which is stable to variations in image acquisition parameters and to evaluate the effect of image preprocessing on radiomic features stabili...

journal_title：Medical physics

authors： Bologna M,Corino V,Mainardi L

更新日期：2019-11-01 00:00:00

abstract：:In this report we evaluate an image registration technique that can improve the information content of intraoperative image data by deformable matching of preoperative images. In this study, pretreatment 1.5 tesla (T) magnetic resonance (MR) images of the prostate are registered with 0.5 T intraoperative images. The m...

journal_title：Medical physics

authors： Bharatha A,Hirose M,Hata N,Warfield SK,Ferrant M,Zou KH,Suarez-Santana E,Ruiz-Alzola J,D'Amico A,Cormack RA,Kikinis R,Jolesz FA,Tempany CM

更新日期：2001-12-01 00:00:00

abstract：:The purpose of this work is to investigate algorithms for the delivery of intensity-modulated fields using independent collimators (IC). Two heuristic algorithms are proposed to calculate jaw-setting sequences for arbitrary 2D intensity distributions. The first algorithm is based on searching the whole intensity matri...

journal_title：Medical physics

authors： Dai JR,Hu YM

更新日期：1999-12-01 00:00:00

abstract：:Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are pre...

journal_title：Medical physics

authors： Zilio VO,Joneja OP,Popowski Y,Rosenfeld A,Chawla R

更新日期：2006-06-01 00:00:00

abstract：:An automated data-acquisition and analysis system has been developed for dosimetry measurements on the pion therapy beam at the Clinton P. Anderson Meson Physics Facility Biomedical Channel in Los Alamos using a PDP-11/45 computer and CAMAC interface. Initialization, test, and monitor programs allow the user to set th...

journal_title：Medical physics

authors： Rosen I,Smith A,Lane R,Kelsey C,Lake D,Hogstrom K,Somers J,Helland J,Kittell R,Amols H,Bradbury J,Richman C

更新日期：1978-03-01 00:00:00

abstract：:Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common--they can give a significant radiation dose to the patient....

journal_title：Medical physics

authors： Murphy MJ,Balter J,Balter S,BenComo JA Jr,Das IJ,Jiang SB,Ma CM,Olivera GH,Rodebaugh RF,Ruchala KJ,Shirato H,Yin FF

更新日期：2007-10-01 00:00:00

abstract：PURPOSE:The ionizing radiation imparted to patients during computed tomography exams is raising concerns. This paper studies the performance of a scheme called dose reduction using prior image constrained compressed sensing (DR-PICCS). The purpose of this study is to characterize the effects of a statistical model of x...

journal_title：Medical physics

authors： Lauzier PT,Chen GH

更新日期：2013-02-01 00:00:00

abstract：PURPOSE:In radiotherapy, it is important to predict the response of tumors to irradiation prior to the treatment. This is especially important for hypoxic tumors, which are known to be highly radioresistant. Mathematical modeling based on the dose distribution, biological parameters, and medical images may help to impr...

journal_title：Medical physics

authors： Espinoza I,Peschke P,Karger CP

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:A critical step in adaptive radiotherapy (ART) workflow is deformably registering the simulation CT with the daily or weekly volumetric imaging. Quantifying the deformable image registration accuracy under these circumstances is a complex task due to the lack of known ground-truth landmark correspondences betwe...

journal_title：Medical physics

authors： Neylon J,Min Y,Low DA,Santhanam A

更新日期：2017-08-01 00:00:00

abstract：:An anthropomorphic 1H MRS head phantom has been developed which mimics the in vivo structure, metabolite concentrations, and relaxation times (for both water and metabolites) of human brain tissue. Different brain regions and two tumor types, fluid-containing ventricles, and air-filled sinus, and subcutaneous fat are ...

journal_title：Medical physics

authors： Rice JR,Milbrandt RH,Madsen EL,Frank GR,Boote EJ,Blechinger JC

更新日期：1998-07-01 00:00:00

abstract：PURPOSE:To assess the image quality, scatter, and leakage radiation of an integrated magnetic resonance linear accelerator (MR-LINAC or MRL) system. METHODS:A large American College of Radiology (ACR) magnetic resonance imaging (MRI) accreditation phantom was used to evaluate the MRI capabilities of the integrated MRL...

journal_title：Medical physics

authors： Wang J,Yung J,Kadbi M,Hwang K,Ding Y,Ibbott GS

更新日期：2018-03-01 00:00:00