SU-E-T-203: Development of a QA Software Tool for Automatic Verification of Plan Data Transfer and Delivery.

abstract：:The physical imaging performance of ST-V, ST-VA, and ST-VN computed radiography image plates, read with a Philips AC3 acquisition system, was investigated at 70 kVp with 0.5 mm of copper beam filtration for four different entrance air kerma values: 0.5, 2.6, 26, and 260 micro Gy. Measurements included characteristic r...

journal_title：Medical physics

authors： Kengyelics SM,Davies AG,Cowen AR

更新日期：1998-11-01 00:00:00

abstract：:A simple approach was developed that calculates the output factors and tissue maximum ratio of an asymmetric field at any point within the open field, and specifically both at the central axis (when the jaws do not shadow it) and at the effective center of the open field, using the existing tables for symmetric fields...

journal_title：Medical physics

authors： Rosenberg I,Chu JC,Saxena V

更新日期：1995-01-01 00:00:00

abstract：:Spread of invasive carcinoma throughout breast tissue is believed to occur at supramolecular levels, beyond the range of standard histopathology identification. Small angle x-ray scattering (SAXS) is capable of characterizing the structural properties of collagen and tissue found in the breast at the scale of tens to ...

journal_title：Medical physics

authors： Sidhu S,Siu KK,Falzon G,Hart SA,Foxe JG,Lewis RA

更新日期：2009-07-01 00:00:00

abstract：:A computer program was implemented to predict mammography x-ray beam parameters in the range 20-40 kV for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations. The computation method used to simulate mammography x-ray spectra is based on the Boone et al. model. The beam quality parameters such as the half-value la...

journal_title：Medical physics

authors： Kharrati H,Zarrad B

更新日期：2003-10-01 00:00:00

abstract：:A calculation is described that enables the rapid assessment of dose rate at various points of interest within the eye (lens, optic nerve, etc.) for the treatment of choroidal melanoma by plaque therapy. 125I seeds are used as the radiation source. The location of the plaque and its associated seeds relative to the ey...

journal_title：Medical physics

authors： Kepka AG,Johnson PM,Kline RW

更新日期：1988-05-01 00:00:00

abstract：:Computer algorithms for rotational therapy beams, in most cases, perform dose calculations by summing stored fixed beam data at finite angular steps. Such an algorithm, based on the Bentley beam model, was evaluated by comparing calculations with measured data for an 18-MV x-ray beam. Measurements were made in a speci...

journal_title：Medical physics

authors： Kurup RG,Hogstrom KR,Hwang CC

更新日期：1987-11-01 00:00:00

abstract：PURPOSE:Robust registration of prone and supine colonie surfaces acquired during CT colonography may lead to faster and more accurate detection of colorectal cancer and polyps. Any directional bias when registering one surface to the other could precipitate incorrect anatomical correspondence and engender reader error....

journal_title：Medical physics

authors： Roth H,McClelland J,Modat M,Hampshire T,Boone D,Hu M,Ourselin S,Halligan S,Hawkes D

更新日期：2012-06-01 00:00:00

abstract：:New radiation therapy techniques such as IMRT present significant efficiency due to their highly conformal dose distributions. A consequence of the complexity of their dose distributions (high gradients, small irradiation fields, low dose distribution, ...) is the requirement for better precision quality assurance tha...

journal_title：Medical physics

authors： Frelin AM,Fontbonne JM,Ban G,Colin J,Labalme M,Batalla A,Vela A,Boher P,Braud M,Leroux T

更新日期：2008-05-01 00:00:00

abstract：PURPOSE:For the purpose of size-specific dose estimation, information regarding patient attenuation is required. The purpose of this work is to describe a method for measuring patient attenuation and expressing the results in terms of a water cylinder, with cross sectional area A(w), which would absorb the same average...

journal_title：Medical physics

authors： Wang J,Duan X,Christner JA,Leng S,Yu L,McCollough CH

更新日期：2012-11-01 00:00:00

abstract：PURPOSE:Quantitative cone-beam CT (CBCT) imaging is on increasing demand for high-performance image guided radiation therapy (IGRT). However, the current CBCT has poor image qualities mainly due to scatter contamination. Its current clinical application is therefore limited to patient setup based on only bony structure...

journal_title：Medical physics

authors： Niu T,Al-Basheer A,Zhu L

更新日期：2012-04-01 00:00:00

abstract：:The purpose of this study is to develop a 4D inverse planning strategy capable of controlling the appearance of the implanted fiducial(s) in segmented IMRT fields for cine MV or combined MV/kV image-guided IMRT. This work is focused on enhancing the visibility of the implanted fiducial(s) in 4D IMRT inverse planning, ...

journal_title：Medical physics

authors： Ma Y,Lee L,Keshet O,Keall P,Xing L

更新日期：2009-06-01 00:00:00

abstract：:High false-positive (FP) rate remains to be one of the major problems to be solved in CAD study because too many false-positively cued signals will potentially degrade the performance of detecting true-positive regions and increase the call-back rate in CAD environment. In this paper, we proposed a novel classificatio...

journal_title：Medical physics

authors： Li L,Zheng Y,Zhang L,Clark RA

更新日期：2001-02-01 00:00:00

abstract：PURPOSE:Cone beam computed tomography (CBCT) image quality suffers from contamination from scattered photons in the projection images. Monte Carlo simulations are a powerful tool to investigate the properties of scattered photons.egs_cbct, a recent EGSnrc user code, provides the ability of performing fast scatter calcu...

journal_title：Medical physics

authors： Thing RS,Mainegra-Hing E

更新日期：2014-07-01 00:00:00

abstract：PURPOSE:A practical detector structure is proposed to achieve stable avalanche multiplication gain in direct-conversion amorphous selenium radiation detectors. METHODS:The detector structure is referred to as a field-shaping multi-well avalanche detector. Stable avalanche multiplication gain is achieved by eliminating...

journal_title：Medical physics

authors： Goldan AH,Zhao W

更新日期：2013-01-01 00:00:00

abstract：:Two side-by-side energy windows are sometimes employed in quantitative single photon emission computed tomography (SPECT) studies. The count-rate losses at high activities for a GE400AT camera were measured in such a dual-window-acquisition mode by imaging a decaying source composed of a hot sphere within a warm cylin...

journal_title：Medical physics

authors： Zasadny KR,Koral KF,Swailem FM

更新日期：1993-07-01 00:00:00

abstract：PURPOSE:Total and regional body composition are important indicators of health and mortality risk, but their measurement is usually restricted to controlled environments in clinical settings with expensive and specialized equipment. A method that approaches the accuracy of the current gold standard method, dual-energy ...

journal_title：Medical physics

authors： Tian IY,Ng BK,Wong MC,Kennedy S,Hwaung P,Kelly N,Liu E,Garber AK,Curless B,Heymsfield SB,Shepherd JA

更新日期：2020-12-01 00:00:00

abstract：:The MCNP Monte Carlo radiation transport code was modified for diagnostic medical physics applications. In particular, the modified code was thoroughly benchmarked for the production of polychromatic tungsten x-ray spectra in the 30-150 kV range. Validating the modified code for coupled electron-photon transport with ...

journal_title：Medical physics

authors： Mercier JR,Kopp DT,McDavid WD,Dove SB,Lancaster JL,Tucker DM

更新日期：2000-12-01 00:00:00

abstract：:Cardiac arrhythmias are a major health burden, associated with reduced quality of life and substantial morbidity and mortality. Current therapy includes moderately effective medication and catheter-based ablation of arrhythmogenic substrates in the heart. Catheter interventions frequently have to be repeated due to re...

journal_title：Medical physics

authors： Graeff C,Bert C

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:Positron emission tomography (PET) is considered the gold standard for measuring myocardial blood flow in vivo but it is known that respiratory motion can lead to misalignment of the PET and computed tomography (CT) data sets and introduce artifacts in the CT-based attenuation correction (AC) of images. In addi...

journal_title：Medical physics

authors： Pourmoghaddas A,Klein R,deKemp RA,Wells RG

更新日期：2013-02-01 00:00:00

abstract：:An artificial neural network using input data derived from attenuation measurements was trained to generate spectral profiles (relative number of photons versus energy). Once the relative spectral distribution is reconstructed, absolute spectra (number of photons per unit exposure spectral distribution is reconstructe...

journal_title：Medical physics

authors： Boone JM

更新日期：1990-07-01 00:00:00

abstract：PURPOSE:The authors describe the integration of optical imaging with a targeted small animal irradiator device, focusing on design, instrumentation, 2D to 3D image registration, 2D targeting, and the accuracy of recovering and mapping the optical signal to a 3D surface generated from the cone-beam computed tomography (...

journal_title：Medical physics

authors： Weersink RA,Ansell S,Wang A,Wilson G,Shah D,Lindsay PE,Jaffray DA

更新日期：2014-10-01 00:00:00

abstract：PURPOSE:Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach c...

journal_title：Medical physics

authors： Heine JJ,Cao K,Beam C

更新日期：2009-12-01 00:00:00

abstract：PURPOSE:Transrectal ultrasound (TRUS)-guided needle biopsy is the current gold standard for prostate cancer diagnosis. However, up to 40% of prostate cancer lesions appears isoechoic on TRUS. Hence, TRUS-guided biopsy has a high false negative rate for prostate cancer diagnosis. Magnetic resonance imaging (MRI) is bett...

journal_title：Medical physics

authors： Sparks R,Bloch BN,Feleppa E,Barratt D,Moses D,Ponsky L,Madabhushi A

更新日期：2015-03-01 00:00:00

abstract：PURPOSE:We propose a new method for efficient particle transportation in voxelized geometry for Monte Carlo simulations. We describe its use for calculating dose distribution in CT images for radiation therapy. MATERIAL AND METHODS:The proposed approach, based on an implicit volume representation named segmented volum...

journal_title：Medical physics

authors： Sarrut D,Guigues L

更新日期：2008-04-01 00:00:00

abstract：:Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides 137Cs, 125I, 192Ir, 103Pd, and 169Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of pha...

journal_title：Medical physics

authors： Melhus CS,Rivard MJ

更新日期：2006-06-01 00:00:00

abstract：PURPOSE:Automated segmentation could improve the efficiency of modeling-based pelvic organ prolapse (POP) evaluations. However, segmentation performance is limited by the blurry soft tissue boundaries. In this study, we aimed to present a hybrid solution for uterus, rectum, bladder, and levator ani muscle segmentation ...

journal_title：Medical physics

authors： Feng F,Ashton-Miller JA,DeLancey JOL,Luo J

更新日期：2020-09-01 00:00:00

abstract：:Increasing output resolution is assumed to improve noise characteristics of a CCD digitizer. In this work, however, we have found that as the quantization step becomes lower than the analog noise (present in the signal before its conversion to digital) the noise reduction becomes significantly lower than expected. Tha...

journal_title：Medical physics

authors： González A,Martínez JA,Tobarra B

更新日期：2004-03-01 00:00:00

abstract：PURPOSE:Transcranial focused ultrasound is an emerging therapeutic modality that can be used to perform noninvasive neurosurgical procedures. The current clinical transcranial phased array operates at 650 kHz, however the development of a higher frequency array would enable more precision, while reducing the risk of st...

journal_title：Medical physics

authors： Pajek D,Hynynen K

更新日期：2013-12-01 00:00:00

abstract：PURPOSE:TransitQA is an innovative method for Tomotherapy transit dosimetry using the on-board detector (OBD). Our previously published model for Tomotherapy treatment plan verification (AirQA) has been enhanced to take into account patient and couch transmission. AirQA estimates the OBD signal during irradiation with ...

journal_title：Medical physics

authors： Pisaturo O,Miéville F,Tercier PA,Allal AS

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:To compare and evaluate intensity-based registration methods for computation of serial x-ray mammogram correspondence. METHODS:X-ray mammograms were simulated from MRIs of 20 women using finite element methods for modeling breast compressions and employing a MRI/x-ray appearance change model. The parameter con...

journal_title：Medical physics

authors： Pinto Pereira SM,Hipwell JH,McCormack VA,Tanner C,Moss SM,Wilkinson LS,Khoo LA,Pagliari C,Skippage PL,Kliger CJ,Hawkes DJ,Silva IM

更新日期：2010-09-01 00:00:00