Technical note: patient-specific quality assurance methods for TomoDirect(TM) whole breast treatment delivery.

abstract：PURPOSE:Accurate segmentation of lungs with severe interstitial lung disease (ILD) in thoracic computed tomography (CT) is an important and difficult task in the development of computer-aided diagnosis (CAD) systems. Therefore, we developed in this study a texture analysis-based method for accurate segmentation of lung...

journal_title：Medical physics

authors： Wang J,Li F,Li Q

更新日期：2009-10-01 00:00:00

abstract：PURPOSE:Our aim was to compare different magnet arrangements for magnetic cell delivery to human lower leg arteries and investigate the theoretical targeting efficiency under realistic flow conditions as a possible treatment after angioplasty. Additionally the potential of scaling down or translating the magnetic actua...

journal_title：Medical physics

authors： Riegler J,Lau KD,Garcia-Prieto A,Price AN,Richards T,Pankhurst QA,Lythgoe MF

更新日期：2011-07-01 00:00:00

abstract：PURPOSE:The small number of samples available for training and testing is often the limiting factor in finding the most effective features and designing an optimal computer-aided diagnosis (CAD) system. Training on a limited set of samples introduces bias and variance in the performance of a CAD system relative to that...

journal_title：Medical physics

authors： Way TW,Sahiner B,Hadjiiski LM,Chan HP

更新日期：2010-02-01 00:00:00

abstract：:A nondestructive and noninvasive method for numeric characterization (quantification) of the structural composition of human bone tissue has been developed and tested. In order to quantify and to compare the structural composition of bones from 2D computed tomography (CT) images acquired at different skeletal location...

journal_title：Medical physics

authors： Saparin P,Thomsen JS,Kurths J,Beller G,Gowin W

更新日期：2006-10-01 00:00:00

abstract：:Noise, partial volume (PV) effect, and image-intensity inhomogeneity render a challenging task for segmentation of brain magnetic resonance (MR) images. Most of the current MR image segmentation methods focus on only one or two of the above-mentioned effects. The objective of this paper is to propose a unified framewo...

journal_title：Medical physics

authors： Li X,Li L,Lu H,Liang Z

更新日期：2005-07-01 00:00:00

abstract：:The method of magnetic resonance imaging (MRI) was an extension of nuclear magnetic resonance (NMR) spectroscopy that was enabled by computational systems capable of performing the Fast Fourier Transform. Initially, a diverse group of methods were proposed for producing images with NMR, with the multi-slice spin-warp ...

journal_title：Medical physics

authors： Clarke G

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:The Nakagami statistical model and Nakagami shape parameter m have been widely used in linear tissue characterization and preliminarily characterized the envelope distributions of nonlinear encapsulated microbubbles (EMBs). However, the Nakagami distribution of nonlinear scattering EMBs lacked a systematical in...

journal_title：Medical physics

authors： Wang D,Sang Y,Zhang X,Hu H,Lu S,Zhang Y,Fu C,Cloutier G,Wan M

更新日期：2019-12-01 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 present study was conducted to investigate salivary iodine kinetics and dosimetry during repeated courses of radioiodine ((131)I) therapy for differentiated thyroid cancer (DTC). Such data could provide a better understanding of the mechanisms of (131)I induced salivary toxicity and help to develop appropri...

journal_title：Medical physics

authors： Liu B,Huang R,Kuang A,Zhao Z,Zeng Y,Wang J,Tian R

更新日期：2011-10-01 00:00:00

abstract：PURPOSE:Urinary particles are particularly important parameters in clinical urinalysis, especially for the diagnosis of nephropathy. Therefore, it is highly important to precisely detect urinary particles in the clinical setting. However, artificial microscopy is subjective and time consuming, and various previous dete...

journal_title：Medical physics

authors： Li Q,Yu Z,Qi T,Zheng L,Qi S,He Z,Li S,Guan H

更新日期：2020-07-01 00:00:00

abstract：:The authors are investigating the concept of a direct-conversion flat-panel imager with avalanche gain for low-dose x-ray imaging. It consists of an amorphous selenium (a-Se) photoconductor partitioned into a thick drift region for x-ray-to-charge conversion and a relatively thin region called high-gain avalanche rush...

journal_title：Medical physics

authors： Wronski MM,Rowlands JA

更新日期：2008-12-01 00:00:00

abstract：:The purpose of the present study is to characterize electron contamination in photon beams in different clinical situations. Variations with field size, beam modifier (tray, shaping block) and source-surface distance (SSD) were studied. Percentage depth dose measurements with and without a purging magnet and replacing...

journal_title：Medical physics

authors： Lopez Medina A,Teijeiro A,Garcia J,Esperon J,Terron JA,Ruiz DP,Carrion MC

更新日期：2005-05-01 00:00:00

abstract：:Neutron energy spectra and spectra of dose deposition in tissue-equivalent material have been measured for neutron sources produced by 16-, 22-, 35-, and 45.5-MeV deuterons and 22.5-, 35-, 45-, and 65.5-MeV protons incident upon a thick beryllium target. Neutron spectra were measured using time-of-flight techniques an...

journal_title：Medical physics

authors： Heintz PH,Johnsen SW,Peek NF

更新日期：1977-05-01 00:00:00

abstract：:In this work, the authors have evaluated ten different ionization chambers for the relative dosimetry of kilovoltage x-ray beams in the energy range of 50-280 kVp. Percentage depth doses in water and relative detector response (in Solid Water and in air) were measured for each of the x-ray beams studied using a number...

journal_title：Medical physics

authors： Hill R,Mo Z,Haque M,Baldock C

更新日期：2009-09-01 00:00:00

abstract：PURPOSE:Automated detection of solitary pulmonary nodules using positron emission tomography (PET) and computed tomography (CT) images shows good sensitivity; however, it is difficult to detect nodules in contact with normal organs, and additional efforts are needed so that the number of false positives (FPs) can be fu...

journal_title：Medical physics

authors： Teramoto A,Fujita H,Yamamuro O,Tamaki T

更新日期：2016-06-01 00:00:00

abstract：:The observation of scattered radiations of larger wavelength than the primary had been repeatedly rejected or explained away by many researchers, including Compton. After years of vacillations, he recognized the effect named after him and was the first to develop a quantal equation predicting the wavelength of scatter...

journal_title：Medical physics

authors： del Regato JA

更新日期：1981-11-01 00:00:00

abstract：PURPOSE:The authors introduce a novel method for defining standardized uptake values (SUVs) in PET∕CT based on routinely collected CT data. The goal of the study is to reduce, if possible, the variability of SUV in a heterogeneous population. Two well established methods for defining SUV are based on body weight (BW) a...

journal_title：Medical physics

authors： Hamill JJ,Sunderland JJ,LeBlanc AK,Kojima CJ,Wall J,Martin EB

更新日期：2013-09-01 00:00:00

abstract：:A direct data link between a CT scanner and a radiation treatment planning system has been developed. The link transmits the data serially over a coaxial cable using the pseudo-paper-tape punch and reader (serial PIO) interfaces. The data transmission rate with error-check is approximately 25,000 8-bit bytes/s. This t...

journal_title：Medical physics

authors： Abel RN,Buhler LA,Chu WT,Slater JM,Neilsen IR,Zimmerman DC

更新日期：1979-09-01 00:00:00

abstract：:The dosimetry for radiocolloid therapy of cystic craniopharyngiomas is investigated. Analytical calculations based on the Loevinger and the Berger formulas for electrons and photons, respectively, are compared with Monte Carlo simulations. The role of the material of which the colloid introduced inside the craniophary...

journal_title：Medical physics

authors： Rojas EL,Al-Dweri FM,Lallena AM,Bodineau C,Galán P

更新日期：2003-09-01 00:00:00

abstract：PURPOSE:For stereotactic radiosurgery (SRS), accurate evaluation of dose-volume metrics for small structures is necessary. The purpose of this study was to compare the DVH metric capabilities of five commercially available SRS DVH analysis tools (Eclipse, Elements, Raystation, MIM, and Velocity). METHODS:DICOM RTdose ...

journal_title：Medical physics

authors： Stanley DN,Covington E,Liu H,Alexandrian A,Cardan R,Bridges D,Thomas EM,Fiveash JB,Popple R

更新日期：2020-12-09 00:00:00

abstract：:A technique was developed to reduce the size and magnitude of the hot and cold spots in the abutting regions of photon and electron fields. The photon and electron fields were set up such that the photon field extended approximately 2 cm into the electron field in the abutting region. The region of the photon beam tha...

journal_title：Medical physics

authors： Li JG,Xing L,Boyer AL,Hamilton RJ,Spelbring DR,Turian JV

更新日期：1999-11-01 00:00:00

abstract：:The effective energy of the x-ray beam from linear accelerators changes as a function of the position in the beam due to nonuniform filtration by the flattening filter. In this work, the transmittance through a water column was measured in good geometry and the beam quality characterized in units of HVL in water. Meas...

journal_title：Medical physics

authors： Hanson WF,Berkley LW,Peterson M

更新日期：1980-03-01 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：:Angioplasty balloons inflated with a solution of the beta-emitter Re-188 have been used for intravascular brachytherapy to prevent restenosis. Coronary stents are in extensive clinical use for the treatment of de novo atherosclerotic stenoses. In this study, the effect of an interposed stent on the dose distribution h...

journal_title：Medical physics

authors： Wuu CS,Schiff P,Maryanski MJ,Liu T,Borzillary S,Weinberger J

更新日期：2003-02-01 00:00:00

abstract：PURPOSE:Formation of new blood vessels (angiogenesis) in response to hypoxia is a fundamental event in the process of tumor growth and metastatic dissemination. However, abnormalities in tumor neovasculature often induce increased interstitial pressure (IP) and further reduce oxygenation (pO2) of tumor cells. In radiot...

journal_title：Medical physics

authors： Lagerlöf JH,Kindblom J,Bernhardt P

更新日期：2011-08-01 00:00:00

abstract：PURPOSE:High-dose-rate brachytherapy (HDR-BT) is a treatment option for malignant skin diseases compared to external beam radiation therapy, HDR-BT provides improved target coverage, better organ sparing, and has comparable treatment times. This is especially true for large clinical targets with complex topologies. To ...

journal_title：Medical physics

authors： Guthier CV,Devlin PM,Harris TC,O'Farrell DA,Cormack RA,Buzurovic I

更新日期：2020-03-01 00:00:00

abstract：:A method for optimizing MR imaging pulse sequence parameters in a statistical framework is presented. Parameters are defined to be optimal when the resulting scalar images yield optimal image segmentations using Bayesian pixel classification. Thus, Bayes risk is used as the objective function to minimize. Approximatio...

journal_title：Medical physics

authors： Prince JL,Pham D,Tan O

更新日期：1995-10-01 00:00:00

abstract：PURPOSE:The efficiency of radioembolization procedures could be greatly enhanced if results of the 99m Tc-MAA pretreatment procedure were immediately available in the interventional suite, enabling 1-day procedures as a result of direct estimation of the hepatic radiation dose and lung shunt fraction. This would, howev...

journal_title：Medical physics

authors： van der Velden S,Dietze MMA,Viergever MA,de Jong HWAM

更新日期：2019-01-01 00:00:00

abstract：:Lag and residual contrast have been quantified in an amorphous selenium (a-Se) active-matrix flat-panel imager (AMFPI) as a function of frame time, kilovoltage (kV) and megavoltage (MV) x-ray photon energies and amount of radiation incident on the detector. The AMFPI contains a 200 microm thick a-Se layer deposited on...

journal_title：Medical physics

authors： Schroeder C,Stanescu T,Rathee S,Fallone BG

更新日期：2004-05-01 00:00:00

abstract：:The feasibility of using film dosimetry data as the input data for patient treatment planning was evaluated. The central-axis depth dose and the off-axis ratios obtained from film measurements in a solid phantom were compared with those of ion-chamber measurements in water. Two techniques were used to generate isodose...

journal_title：Medical physics

authors： Shiu AS,Otte VA,Hogstrom KR

更新日期：1989-11-01 00:00:00