Abstract：
:Radiation therapy treatment modalities continue to develop and have become increasingly complex. With this, dose verification and quality assurance (QA) is of great importance to ensure that a prescribed dose is accurately and precisely delivered to a patient. Radiochromic film dosimetry has been adopted as a convenient option for QA, because it is relatively energy independent, is near tissue equivalent, and has high spatial resolution. Unfortunately, it is not always easy to use. In this study, preliminary work towards developing a novel method of imaging radiochromic film is presented. The setup consists of a camera mounted vertically above a lightbox containing red LEDs, interfaced with computer image acquisition software. Imaging results from this system will be compared with imaging performed using an Epson Expression 10000XL scanner (a device in common clinical use). The lightbox imaging technique with camera readout is much faster relative to a flatbed scanner. The film measurements made using the camera are independent of film orientation, and show reduced artifacts, so that there are fewer corrections required compared to the use of flatbed scanners. Optical scatter also appears to be less of an issue with this design than with the flat bed scanner. While further work needs to be done to optimize the lightbox imaging system, the lightbox system shows great promise for a rapid, simple, and orientation independent setup, improving on existing film scanning systems.
journal_name
Med Physjournal_title
Medical physicsauthors
Alexander K,Percy E,Olding T,Schreiner LJ,Salomons Gdoi
10.1118/1.4740126subject
Has Abstractpub_date
2012-07-01 00:00:00pages
4627issue
7Part3eissn
0094-2405issn
2473-4209journal_volume
39pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:An analytic representation proposed for the relative intensity distribution of the extra-focal source in a two-component x-ray source model serves as the basis for calculation. From this representation, a closed-form expression for head scatter factors defined on the central beam axis is derived by integrating over th...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597494
更新日期：1995-12-01 00:00:00
abstract：:Empirical functions that describe primary beam profiles for radiotherapy treatment planning systems generally account for finite source size only on beams unmodified by blocks, wedges, or compensating filters. To incorporate the effects of extended sources on such modified beams and to treat the effect of an extended ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596222
更新日期：1988-09-01 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
pub_type： 杂志文章
doi：10.1002/mp.14745
更新日期：2021-02-02 00:00:00
abstract：PURPOSE:The purpose of this work was to assess the inherent image quality characteristics of a new multidetector computed tomography system in terms of noise, resolution, and detectability index as a function of image acquisition and reconstruction for a range of clinically relevant settings. METHODS:A multisized imag...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4923172
更新日期：2015-08-01 00:00:00
abstract：:Attention is given to means of sensing ultrasonic energy distributions over an area. Under the restraints appropiate to real-time imaging of deep body organs, piezoelectric arrays offer the most promising method. Adaptation of integrated circuit techniques to array assembly permits very large arrays of small elements ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594247
更新日期：1976-09-01 00:00:00
abstract：:Tumor cells can be killed by heating to 42.5 degrees C. It is convenient to localize heating by passing electric current at 500 kHz through tissue between a pair of electrodes. It is desirable to determine, for a given electrode-tissue configuration, what the resulting field and, therefore, current distribution will b...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594235
更新日期：1976-07-01 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
pub_type： 杂志文章
doi：10.1002/mp.14492
更新日期：2020-12-01 00:00:00
abstract：PURPOSE:Optically stimulated luminescence (OSL) dosimetry has been recently introduced in radiation therapy as a potential alternative to the thermoluminescent dosimeter (TLD) system. The aim of this study was to investigate the feasibility of using OSL point dosimeters in the energy range used in diagnostic imaging. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3602456
更新日期：2011-07-01 00:00:00
abstract：PURPOSE:Adding magnetic resonance (MR)-derived information to standard transrectal ultrasound (TRUS) images for guiding prostate biopsy is of substantial clinical interest. A tumor visible on MR images can be projected on ultrasound (US) by using MR-US registration. A common approach is to use surface-based registratio...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4917481
更新日期：2015-05-01 00:00:00
abstract：PURPOSE:CT reconstruction algorithms implemented on the GPU are highly sensitive to their implementation details and the hardware they run on. Fine-tuning an implementation for optimal performance can be a time consuming task and require many updates when the hardware changes. There are some techniques that do automati...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4773045
更新日期：2013-03-01 00:00:00
abstract：PURPOSE:The purpose of this study was to assess the accuracy of a Monte Carlo simulation-based method for estimating radiation dose from multidetector computed tomography (MDCT) by comparing simulated doses in ten patients to in-vivo dose measurements. METHODS:MD Anderson Cancer Center Institutional Review Board appro...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4906178
更新日期：2015-02-01 00:00:00
abstract：PURPOSE:This work is to evaluate the effects of Compton current generation in three small-volume ionization chambers on measured beam characteristics for electron fields. METHODS:Beam scans were performed using Exradin A16, A26, and PTW 31014 microchambers. Scans with varying chamber components shielded were performed...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4929555
更新日期：2015-10-01 00:00:00
abstract：:The anti-scatter grid has been widely used to reject scatter and increase the perceptibility of a low-contrast object in chest radiography; however, it also attenuated the primary x-rays, resulting in a substantial loss of information and an increased relative noise level in heavily attenuated regions. A more dose eff...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2739805
更新日期：2007-07-01 00:00:00
abstract：PURPOSE:Proton computed tomography (pCT) will enable accurate prediction of proton and ion range in a patient while providing the benefit of lower radiation exposure than in x-ray CT. The accuracy of the range prediction is essential for treatment planning in proton or ion therapy and depends upon the detector used to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4939255
更新日期：2016-02-01 00:00:00
abstract：:Traditionally, short scan helical FDK algorithms have been implemented based on horizontal transaxial slices. However, not every point on the horizontal transaxial slice satisfies Tuy's condition for the corresponding (pi+fan angle) segment of helix, which means that some points on the horizontal slices are incomplete...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1916077
更新日期：2005-06-01 00:00:00
abstract：PURPOSE:Arterial distensibility is a marker that can measure vessel wall functional and structural changes resulting from atherosclerosis with applications including estimation of mechanical properties of the wall. We sought to assess the feasibility of using magnetic resonance imaging (MRI) to include wall distensibil...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4754302
更新日期：2012-10-01 00:00:00
abstract：PURPOSE:To provide results of water calorimetry and ion chamber measurements in high-energy electron beams carried out at the National Research Council Canada (NRC). There are three main aspects to this work: (a) investigation of the behavior of ionization chambers in electron beams of different energies with focus on ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12463
更新日期：2017-10-01 00:00:00
abstract：:As different types of radionuclides (e.g., 131Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2905356
更新日期：2008-06-01 00:00:00
abstract：PURPOSE:The lateral edge of a proton therapy beam is commonly used to achieve conformality to the treatment volume where critical structures reside close to the target. However, when treating shallow depths, the lateral edge of a pencil beam scanning (PBS) system may be broader than that of a double scattered (DS) syst...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4941957
更新日期：2016-03-01 00:00:00
abstract：:In order to understand the role of water desorption, i.e., the opposite of water adsorption, in optical clearing of biological tissue created by the application of hyperosmotic agents, dynamics of water loss in fresh porcine muscle tissue administrated with glycerol or ethylene glycol was investigated with the near-in...
journal_title：Medical physics
pub_type：
doi：10.1118/1.1576228
更新日期：2003-06-01 00:00:00
abstract：PURPOSE:Deformable image registration (DIR) is often validated based on a distance-to-agreement (DTA) criterion of automatically propagated anatomical landmarks that were manually identified. Due to human observer variability, however, the performance of the registration method is diluted. The purpose of this study was...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4760990
更新日期：2012-11-01 00:00:00
abstract：PURPOSE:To develop a real-time markerless 3D tumor tracking using kilovoltage (kV) cone-beam CT (CBCT) projection images during volumetric modulated arc therapy (VMAT) treatment of lung tumors. METHODS:The authors have developed a method to identify the position of lung tumors during VMAT treatment, where the current ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4821545
更新日期：2013-10-01 00:00:00
abstract：:The minimum margins required to compensate for random geometric uncertainties in the delivery of radiotherapy treatment were determined for a spherical Clinical Target Volume, using an analytic model for the cumulative dose. Margins were calculated such that the minimum dose in the target would be no less than 95% of ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1809991
更新日期：2004-11-01 00:00:00
abstract：:For an effective radiotherapy the exact tumor location must be determined. The localization has to take into account patient's setup position as well as internal organ motion. Among the different localization methods, the use of a computer tomography (CT) scanner in the therapy room has been proposed recently. Achievi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2103447
更新日期：2005-11-01 00:00:00
abstract：PURPOSE:To measure the calibration curves of EBT3 dosimetry films in photon and proton beams and to quantify the related uncertainties from one beam type to another. METHODS:EBT3 Gafchromic films have similar properties than EBT2 with a symmetric construction and a matte polyester substrate to prevent Newton's ring ar...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735176
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Air-communicating well ionization chambers are commonly used to assess air kerma strength of sources used in brachytherapy. The signal produced is supposed to be proportional to the air density within the chamber and, therefore, a density-independent air kerma strength is obtained when the measurement is correc...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4831757
更新日期：2013-12-01 00:00:00
abstract：PURPOSE:To develop a computer-driven and thus less user-dependent method, allowing for a simple and straightforward generation of a Monte Carlo (MC) beam model of a scanned proton and carbon ion beam delivery system. METHODS:In a first step, experimental measurements were performed for proton and carbon ion energies i...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14647
更新日期：2020-12-07 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
pub_type： 杂志文章
doi：10.1002/mp.13128
更新日期：2018-10-01 00:00:00
abstract：:A Monte Carlo study of dosimetry for eye plaque brachytherapy is performed. BrachyDose, an EGSnrc user code which makes use of Yegin's multi-geometry package, is used to fully model I125 (model 6711) and Pd103 (model 200) brachytherapy seeds and the standardized plaques of the Collaborative Ocular Melanoma Study (COMS...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3002412
更新日期：2008-12-01 00:00:00
abstract：:Photon point dose kernels and absorbed fractions were generated in water for the full photon emission spectrum of each radionuclide of interest in nuclear medicine, by simulating the transport of particles using Monte Carlo. The kernels were then fitted to a mathematical expression. Absorbed fractions for point source...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597670
更新日期：1996-05-01 00:00:00
