Validation of GPU-accelerated superposition-convolution dose computations for the Small Animal Radiation Research Platform.

abstract：PURPOSE:In the nuclear medicine department, the activity of radiopharmaceuticals is measured using dose calibrators (DCs) prior to patient injection. The DC consists of an ionization chamber that measures current generated by ionizing radiation (emitted from the radiotracer). In order to obtain an activity reading, the...

journal_title：Medical physics

authors： Esquinas PL,Tanguay J,Gonzalez M,Vuckovic M,Rodríguez-Rodríguez C,Häfeli UO,Celler A

更新日期：2016-12-01 00:00:00

abstract：PURPOSE:Low-dose CT has attracted increasing attention due to growing concerns about radiation exposure in medical scans. However, the frugal use of x-ray radiation inevitably reduces the quality of the CT images, introducing artifacts such as noise and streaks which make the reconstructed images difficult to read in c...

journal_title：Medical physics

authors： Xu W,Mueller K

更新日期：2012-08-01 00:00:00

abstract：:An adaptive linear element (Adaline) was developed to estimate the two-dimensional scatter exposure distribution in digital portable chest radiographs (DPCXR). DPCXRs and quantitative scatter exposure measurements at 64 locations throughout the chest were acquired for ten radiographically normal patients. The Adaline ...

journal_title：Medical physics

authors： Lo JY,Floyd CE Jr,Baker JA,Ravin CE

更新日期：1993-07-01 00:00:00

abstract：PURPOSE:Stationary computed tomography (s-CT) conceptually offers several advantages over existing rotating gantry-based CT. Over the last 40 yr, s-CT has been investigated using different technological approaches. We are developing a s-CT system specifically for head/brain imaging using carbon nanotube (CNT)-based fie...

journal_title：Medical physics

authors： Spronk D,Luo Y,Inscoe CR,Lee YZ,Lu J,Zhou O

更新日期：2020-12-31 00:00:00

abstract：:We describe a unique method that allows the comparison of spatially registered ultrasound (SRUS) images and computed tomography-derived contours (CTDCs) that were acquired with a minimal time lapse. As such, we have a tool that will provide validation of the spatial accuracy of the US system and that will allow compar...

journal_title：Medical physics

authors： Molloy JA,Srivastava S,Schneider BF

更新日期：2004-03-01 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:As hypoxic cells are more resistant to photon radiation, it is desirable to obtain information about the oxygen distribution in tumors prior to the radiation treatment. Noninvasive techniques are currently not able to provide reliable oxygenation maps with sufficient spatial resolution; therefore mathematical m...

journal_title：Medical physics

authors： Espinoza I,Peschke P,Karger CP

更新日期：2013-08-01 00:00:00

abstract：PURPOSE:The main objective of this work was to design a comprehensive dosimetry package that would keep all aspects of internal dose calculation within the framework of a single software environment and that would be applicable for a variety of dose calculation approaches. METHODS:Our MATLAB-based graphical user inter...

journal_title：Medical physics

authors： Grimes J,Uribe C,Celler A

更新日期：2013-07-01 00:00:00

abstract：BACKGROUND:X-ray dark-field radiography could enhance mammography by providing more information on imaged tissue and microcalcifications. The dark field signal is a measure of small angle scattering and can thus provide additional information on the imaged materials. This information can be useful for material distinct...

journal_title：Medical physics

authors： Rauch T,Rieger J,Pelzer G,Horn F,Erber R,Wunderle M,Emons J,Nabieva N,Fuhrich N,Michel T,Hartmann A,Fasching PA,Anton G

更新日期：2020-04-01 00:00:00

abstract：PURPOSE:Deformable registration generally relies on the assumption that the sought spatial transformation is smooth. Yet, breathing motion involves sliding of the lung with respect to the chest wall, causing a discontinuity in the motion field, and the smoothness assumption can lead to poor matching accuracy. In respon...

journal_title：Medical physics

authors： Vandemeulebroucke J,Bernard O,Rit S,Kybic J,Clarysse P,Sarrut D

更新日期：2012-02-01 00:00:00

abstract：PURPOSE:There is evidence that computed tomography (CT) and positron emission tomography (PET) imaging metrics are prognostic and predictive in nonsmall cell lung cancer (NSCLC) treatment outcomes. However, few studies have explored the use of standardized uptake value (SUV)-based image features of nodal regions as pre...

journal_title：Medical physics

authors： Li H,Becker N,Raman S,Chan TC,Bissonnette JP

更新日期：2015-08-01 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:For cone-beam computed tomography (CBCT) systems, we propose a sphere phantom based method to estimate the full three-dimensional (3D) modulation transfer function (MTF). METHODS:The FDK reconstruction of CBCT system in a local region was modeled by a triple convolution operator. Afterward, we calculated the d...

journal_title：Medical physics

authors： Lee C,Song HD,Baek J

更新日期：2020-07-01 00:00:00

abstract：:Different methods exist to determine the air kerma calibration factor of an ionization chamber for the spectrum of a 192Ir high-dose-rate (HDR) or pulsed-dose-rate (PDR) source. An analysis of two methods to obtain such a calibration factor was performed: (i) the method recommended by [Goetsch et al., Med. Phys. 18, 4...

journal_title：Medical physics

authors： van Dijk E,Kolkman-Deurloo IK,Damen PM

更新日期：2004-10-01 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

authors： Witte MG,van der Geer J,Schneider C,Lebesque JV,van Herk M

更新日期：2004-11-01 00:00:00

abstract：:This investigation contains the results of exposure measurements on two types of clinical I-125 seeds: a model 6702 no-marker seed, and a model 6711 silver wire seed. Measurements were made locally with a parallel-plate mammography chamber, traceable to the National Bureau of Standards (NBS) calibration. The same seed...

journal_title：Medical physics

authors： Kubo H

更新日期：1985-03-01 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：:A formulation of the single energy photon transport problem is cast in the form of a series of convolutions over the primary fluence distribution with invariant kernels. A method is developed for compensating for the variant intervoxel attenuation in the scattered dose distribution by means of an invariant correction ...

journal_title：Medical physics

authors： Boyer AL,Mok EC

更新日期：1986-07-01 00:00:00

abstract：PURPOSE:In CT-guided liver tumor ablation interventions, registration of a preoperative contrast-enhanced CT image to the intraoperative CT image is hypothesized to improve guidance. This is a highly challenging registration task due to differences in patient poses and large deformations, and therefore high registratio...

journal_title：Medical physics

authors： Gunay G,Luu MH,Moelker A,van Walsum T,Klein S

更新日期：2017-07-01 00:00:00

abstract：PURPOSE:Modern clinical accelerators are capable of producing ion beams from protons up to neon. This work compares the depth dose distribution and corresponding dose averaged linear energy transfer (LET) distribution, which is related to the biological effectiveness, for different ion beams (¹H, ⁴He, ⁶Li, ⁸Be, ¹⁰B, ¹²...

journal_title：Medical physics

authors： Kantemiris I,Karaiskos P,Papagiannis P,Angelopoulos A

更新日期：2011-12-01 00:00:00

abstract：PURPOSE:In this work the performance of a compact multiresolution and multicontrast x-ray phase system based on edge illumination is investigated. It has been designed for small animal imaging and with a limited footprint for ease of deployment in laboratories. METHODS:The presented edge illumination system is based o...

journal_title：Medical physics

authors： Massimi L,Meganck JA,Towns R,Olivo A,Endrizzi M

更新日期：2020-10-27 00:00:00

abstract：PURPOSE:Motion is a major confound of image quality in MRI. A method of retrospectively correcting the effects of rotations and translations on the acquired k-space data is presented. METHODS:In two phantom experiments of well-controlled translation and rotation, two MRI-compatible infrared cameras recorded motion dat...

journal_title：Medical physics

authors： Marxen M,Marmurek J,Baker N,Graham SJ

更新日期：2009-12-01 00:00:00

abstract：PURPOSE:Radiation Therapy (RT) induced pulmonary function change may depend on the location, underlying function of that lung prior to radiations, radiation dose/fractionation and other factors. We propose to evaluate the radiation induced pulmonary function change using static breath-hold MRI scans with vascular infor...

journal_title：Medical physics

authors： Ding K,Cao K,Du K,Chen Q,Ennis D,Christensen G,Reinhardt J,Libby B,Benedict S,Sheng K

更新日期：2012-06-01 00:00:00

abstract：:We are investigating computerized methods to ultimately characterize bone trabecular pattern from clinical skeletal radiographs. In this paper, we present a "phantom" for potential use in the development and evaluation of computerized methods for characterizing radiographic trabecular patterns and ultimately bone stre...

journal_title：Medical physics

authors： Chinander MR,Giger ML,Martell JM,Jiang C,Favus MJ

更新日期：1999-11-01 00:00:00

abstract：:Statistical image reconstruction (SIR) methods have shown potential to substantially improve the image quality of low-dose x-ray computed tomography (CT) as compared to the conventional filtered back-projection (FBP) method. According to the maximum a posteriori (MAP) estimation, the SIR methods are typically formulat...

journal_title：Medical physics

authors： Zhang H,Wang J,Zeng D,Tao X,Ma J

更新日期：2018-10-01 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：:This article provides a quantitative evaluation of Varian Medical Systems' beam matching procedure. A one-dimensional y analysis is employed to investigate the level of agreement of matched beams. A customized concept of one-dimensional gamma evaluation was designed. Our algorithm first performs a "local" fit of the r...

journal_title：Medical physics

authors： Hrbacek J,Depuydt T,Nulens A,Swinnen A,Van den Heuvel F

更新日期：2007-07-01 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：:In this investigation, five experimental data sets are used to evaluate the ability of the EGSnrc Monte Carlo code to calculate the change in chamber response associated with changes in wall material and cavity dimension at 60Co energies. Calculations of the ratios of response per unit mass of air as a function of cav...

journal_title：Medical physics

authors： La Russa DJ,Rogers DW

更新日期：2008-12-01 00:00:00

abstract：PURPOSE:To provide a fast computational method, based on the proximal graph solver (POGS) - A convex optimization solver using the alternating direction method of multipliers (ADMM), for calculating an optimal treatment plan in rotating shield brachytherapy (RSBT). RSBT treatment planning has more degrees of freedom th...

journal_title：Medical physics

authors： Cho M,Wu X,Dadkhah H,Yi J,Flynn RT,Kim Y,Xu W

更新日期：2017-10-01 00:00:00