On the suitability of ultrathin detectors for absorbed dose assessment in the presence of high-density heterogeneities.

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：:An important aspect of heavy charged particle radiotherapy is its ability to localize dose to the target volume. Current techniques generally employ beam delivery schemes which use range modulated beams in which the Bragg peak is spread out over a range of depths. The range modulation is constant over the entire beam ...

journal_title：Medical physics

authors： Goitein M,Chen GT

更新日期：1983-11-01 00:00:00

abstract：PURPOSE:Signal encoding in magnetic particle imaging (MPI) is achieved by moving a field-free point (FFP) through the region of interest. One way to increase the sensitivity of the method is to scan the region of interest with a field-free line (FFL) instead of the FFP. Recently, the first feasible FFL coil setup was i...

journal_title：Medical physics

authors： Knopp T,Erbe M,Biederer S,Sattel TF,Buzug TM

更新日期：2010-07-01 00:00:00

abstract：:Direct comparisons of the National Institute of Standards and Technology's (NIST) Ritz 20 kV to 100 kV standard free-air ionization chamber and a portable variable-length free-air ionization chamber designed by the University of Wisconsin-Madison Accredited Dosimetry Calibration Laboratory (UW-ADCL) were made on NISTs...

journal_title：Medical physics

authors： Coletti JG,Pearson DW,DeWerd LA,O'Brien CM,Lamperti PJ

更新日期：1997-08-01 00:00:00

abstract：PURPOSE:The aim of this study was to develop a dose calculation method which is applicable to the interseed attenuation and the geometry lacking the equilibrium radiation scatter conditions in brachytherapy. METHODS:The dose obtained from measurement with a radiophotoluminescent glass rod dosimeter (GRD) was compared ...

journal_title：Medical physics

authors： Tanaka K,Tateoka K,Asanuma O,Kamo K,Bengua G,Sato K,Ueda T,Takeda H,Takagi M,Hareyama M,Takada J

更新日期：2011-06-01 00:00:00

abstract：:Highly focused dose distributions for radiosurgery applications are successfully achieved using either multiple static high-energy particle beams or multiple-arc circular x-ray beams from a linac. It has been suggested that conformal x-ray techniques using dynamically shaped beams with a moving radiation source would ...

journal_title：Medical physics

authors： Serago CF,Thornton AF,Urie MM,Chapman P,Verhey L,Rosenthal SJ,Gall KP,Niemierko A

更新日期：1995-12-01 00:00:00

abstract：:In this paper, a unified framework of iterative algebraic reconstruction for emission computed tomography (ECT) and its application to positron emission tomography (PET) is presented. The unified framework is based on an algebraic image restoration model and contains conventional iterative algebraic reconstruction alg...

journal_title：Medical physics

authors： Xu XL,Liow JS,Strother SC

更新日期：1993-11-01 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：:One of the key components in modern LINAC room shielding design is the amount of 90 degrees head leakage radiation levels. With the general clinical acceptance of intensity-modulated radiation therapy (IMRT) technique, accurate knowledge of this quantity has become even more important. Measurement of 90 degrees head l...

journal_title：Medical physics

authors： Li Z,Mutic S,Low D

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:To study the impact of target geometrical and linac operational parameters, such as target material and thickness, electron beam size, repetition rate, and mean current on the ability of the radiotherapy treatment head to deliver high-dose-rate x-ray irradiation in the context of novel linear accelerators capab...

journal_title：Medical physics

authors： Wang J,Trovati S,Borchard PM,Loo BW Jr,Maxim PG,Fahrig R

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:Calculations of deoxyribonucleic acid (DNA) damages involve many parameters in the computation process. As these parameters are often subject to uncertainties, it is of central importance to comprehensively quantify their impacts on DNA single-strand break (SSB) and double-strand break (DSB) yields. This has be...

journal_title：Medical physics

authors： Lai Y,Tsai MY,Tian Z,Qin N,Yan C,Hung SH,Chi Y,Jia X

更新日期：2020-04-01 00:00:00

abstract：:A test device which can indirectly measure the performance of an automatic exposure control system and which offers the potential to reduce the time and film requirements for such tests has been evaluated. Evaluation results demonstrate that the device can successfully predict image optical density to within +/- 0.10 ...

journal_title：Medical physics

authors： Rossi RP

更新日期：1994-01-01 00:00:00

abstract：:Nuclear Magnetic Resonance (NMR) permits the noninvasive measurement of blood flow signals unimpaired by clothes, bandages, casts, etc. The cylindrical crossed-coil NMR blood flowmeter was used to measure blood flow through a cross-section of the human forearm. Two calibration procedures are described: one for pulsati...

journal_title：Medical physics

authors： Salles-Cunha SX,Halbach RE,Battocletti JH,Sances A Jr

更新日期：1981-07-01 00:00:00

abstract：PURPOSE:Recent recommendations of the International Commission on Radiological Protection state that the use of effective dose (E) for assessing patient exposure has severe limitations, though it can be kept for dose comparisons. In cardiology procedures, the equivalent dose (H(T)) is one of the most appropriate dose q...

journal_title：Medical physics

authors： Compagnone G,Ortolani P,Domenichelli S,Ovi V,Califano G,Dall'Ara G,Marzocchi A

更新日期：2011-04-01 00:00:00

abstract：:Techniques have been developed for reducing motion blurring artifacts by using respiratory gated computed tomography (CT) in sinogram space and quantitatively evaluating the artifact reduction. A synthetic sinogram was built from multiple scans intercepting a respiratory gating window. A gated CT image was then recons...

journal_title：Medical physics

authors： Lu W,Parikh PJ,Hubenschmidt JP,Politte DG,Whiting BR,Bradley JD,Mutic S,Low DA

更新日期：2005-11-01 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：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

authors： Bashkirov VA,Schulte RW,Hurley RF,Johnson RP,Sadrozinski HF,Zatserklyaniy A,Plautz T,Giacometti V

更新日期：2016-02-01 00:00:00

abstract：PURPOSE:To investigate whether functionally-weighted dose-volume histogram (DVH) parameters are more predictive of radiation-induced pneumonitis (RP) than standard parameters such as V20 and mean lung dose (MLD). MATERIALS AND METHODS:A retrospective chart review identified 26 patients who received curative-intent rad...

journal_title：Medical physics

authors： Hoover D,Reid RH,Rodrigues G,Wong E,Stitt L,Yaremko BP

更新日期：2012-07-01 00:00:00

abstract：:A computationally efficient pseudodynamical filtering setup is established for elasticity imaging (i.e., reconstruction of shear modulus distribution) in soft-tissue organs given statically recorded and partially measured displacement data. Unlike a regularized quasi-Newton method (QNM) that needs inversion of ill-con...

journal_title：Medical physics

authors： Banerjee B,Roy D,Vasu RM

更新日期：2009-08-01 00:00:00

abstract：PURPOSE:To evaluate the accuracy of skin dose determination for composite multibeam 3D conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT) treatments using optically stimulated luminescent dosimeters (OSLDs) and Eclipse treatment planning system. METHODS:Surface doses measured by OSLDs...

journal_title：Medical physics

authors： Zhuang AH,Olch AJ

更新日期：2014-08-01 00:00:00

abstract：PURPOSE:Particle therapy is becoming increasingly available world-wide for precise tumor targeting, its favorable depth dose deposition, and increased biological damage to tumor tissue compared to conventional photon therapy. As demand increases for improved robustness and conformality, next-generation secondary dose c...

journal_title：Medical physics

authors： Kopp B,Fuglsang Jensen M,Mein S,Hoffmann L,Nyström H,Falk M,Haberer T,Abdollahi A,Debus J,Mairani A

更新日期：2020-10-01 00:00:00

abstract：:Weighting of given doses from parallel opposed fields is a widespread practice in radiation therapy of cancer in the tonsillar region. In order to determine when weighting is useful, dose distributions on the central axis were calculated for various energies (60Co, 4-, 8-, 15-, and MVp photons), weighting factors, and...

journal_title：Medical physics

authors： Wollin M,Gilbert HA,Kagan AR

更新日期：1976-03-01 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:To introduce a pair of accelerated non-Cartesian acquisition principles that when combined, exploit the periodicity of k-space acquisition, and thereby enable acquisition of high-temporal cine Cardiac Magnetic Resonance (CMR). METHODS:The mathematical formulation of a noniterative, undersampled non-Cartesian c...

journal_title：Medical physics

authors： Kawaji K,Patel MB,Cantrell CG,Tanaka A,Marino M,Tamura S,Wang H,Wang Y,Carroll TJ,Ota T,Patel AR

更新日期：2017-07-01 00:00:00

abstract：PURPOSE:Micro-CT is widely used for small animal imaging in preclinical studies of cardiopulmonary disease, but further development is needed to improve spatial resolution, temporal resolution, and material contrast. We present a technique for visualizing the changing distribution of iodine in the cardiac cycle with du...

journal_title：Medical physics

authors： Johnston SM,Johnson GA,Badea CT

更新日期：2012-08-01 00:00:00

abstract：PURPOSE:The aim of in vivo skin dosimetry was to measure the absorbed dose to the skin during radiotherapy, when treatment planning calculations cannot be relied on. It is of particularly importance in hypo-fractionated stereotactic modalities, where excessive dose can lead to severe skin toxicity. Currently, commercia...

journal_title：Medical physics

authors： Vicoroski N,Espinoza A,Duncan M,Oborn BM,Carolan M,Metcalfe P,Menichelli D,Perevertaylo VL,Lerch MLF,Rosenfeld AB,Petasecca M

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:The possible clinical applications which can be performed using a newly developed detector depend on the detector's characteristic performance in a number of metrics including the dynamic range, resolution, uniformity, and stability. The authors have evaluated a prototype energy resolved fast photon counting x-...

journal_title：Medical physics

authors： Cho HM,Barber WC,Ding H,Iwanczyk JS,Molloi S

更新日期：2014-09-01 00:00:00

abstract：:To more accurately and precisely delineate a tumor in a 3D PET image, we proposed a novel, semi-automatic, two-stage method by utilizing an adaptive region-growing algorithm and a dual-front active contour model. First, a rough region of interest (ROI) is manually drawn by a radiation oncologist that encloses a tumor....

journal_title：Medical physics

authors： Li H,Thorstad WL,Biehl KJ,Laforest R,Su Y,Shoghi KI,Donnelly ED,Low DA,Lu W

更新日期：2008-08-01 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：:A method is presented for calculation of transmission functions for high energy photon beams through patients. These functions are being used in our clinic for prediction of portal dose images (PDIs) which are compared with PDIs measured with an electronic portal imaging device (EPID). The calculations are based on th...

journal_title：Medical physics

authors： Pasma KL,Heijmen BJ,Kroonwijk M,Visser AG

更新日期：1998-06-01 00:00:00