The response of cells in culture to fractionated radiation: a theoretical approach.

abstract：:This study presents a theoretical approach to the dosimetry for small and non-equilibrium radiation fields. We applied the newly developed VMCBC algorithm to the dosimetry for megavoltage photon beams using Monte Carlo techniques. The approach assumes that a Monte Carlo simulated beam can be calibrated per incident pa...

journal_title：Physics in medicine and biology

authors： Ding GX,Duggan DM,Coffey CW

更新日期：2008-07-07 00:00:00

abstract：:We developed and validated a Monte-Carlo-based application (RAYDOSE) to generate patient-specific 3D dose maps on the basis of pre-treatment imaging studies. A CT DICOM image is used to model patient geometry, while repeated PET scans are employed to assess radionuclide kinetics and distribution at the voxel level. In...

journal_title：Physics in medicine and biology

authors： Marcatili S,Pettinato C,Daniels S,Lewis G,Edwards P,Fanti S,Spezi E

更新日期：2013-04-21 00:00:00

abstract：:Intensity modulated proton radiotherapy (IMPT) can reduce the dose to critical structures by optimizing the distribution and intensity of individual pencil beams. The IMPT can be delivered by dynamically scanning a pencil beam with variable intensity and energy across the tumor target volume. The lateral penumbra of a...

journal_title：Physics in medicine and biology

authors： Safai S,Bortfeld T,Engelsman M

更新日期：2008-03-21 00:00:00

abstract：:This work presents an improvement of the VIPARnd ('nd' stands for 'normoxic, double', or VIP) polymer gel dosimeter. The gel composition was altered by increasing the concentration of the monomeric components, N-vinylpyrrolidone (NVP) and N,N'-methylenebisacrylamide (MBA), in co-solvent solutions. The optimal composit...

journal_title：Physics in medicine and biology

authors： Kozicki M,Jaszczak M,Maras P,Dudek M,Cłapa M

更新日期：2017-02-07 00:00:00

abstract：:Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans ...

journal_title：Physics in medicine and biology

authors： Zhang R,Howell RM,Giebeler A,Taddei PJ,Mahajan A,Newhauser WD

更新日期：2013-02-21 00:00:00

abstract：:An in vivo method for the determination of Cd levels in human kidney and liver has been developed. The method allows detection of absolute quantities of Cd in the left kidney and Cd concentration in the liver. The limit of detection of cadmium is 2.5 mg for the left kidney and 1.8 microgram/g (wet weight) for the live...

journal_title：Physics in medicine and biology

authors： Vartsky D,Ellis KJ,Chen NS,Cohn SH

更新日期：1977-11-01 00:00:00

abstract：:The layer-stacking method can provide three-dimensional conformal dose distributions to the target based on a passive scattering method using mini-spread-out Bragg peak (SOBP). The purpose of this work is to demonstrate the effectiveness of a new weight optimization algorithm that can enhance the robustness of dose di...

journal_title：Physics in medicine and biology

authors： Sakamoto Y,Maeda Y,Yamada Y,Ikeda M,Tameshige Y,Sasaki M,Shibata S,Yamamoto K

更新日期：2020-09-28 00:00:00

abstract：:In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. ...

journal_title：Physics in medicine and biology

authors： Miyamoto N,Ishikawa M,Bengua G,Sutherland K,Suzuki R,Kimura S,Shimizu S,Onimaru R,Shirato H

更新日期：2011-08-07 00:00:00

abstract：:A post-processing noise suppression technique for biomedical MRI images is presented. The described procedure recovers both sharp edges and smooth surfaces from a given noisy MRI image; it does not blur the edges and does not introduce spikes or other artefacts. The fine details of the image are also preserved. The pr...

journal_title：Physics in medicine and biology

authors： Placidi G,Alecci M,Sotgiu A

更新日期：2003-07-07 00:00:00

abstract：:The peak CT number (CT) and full width at half maximum (FWHM) were obtained from the image profiles of aluminium of thickness ranging from 0.1-9.5 mm. The scans were performed at different fields of view (FOVs) and with different reconstruction algorithms ('bone' and 'standard'). Above 3 mm, CT and FWHM provide measur...

journal_title：Physics in medicine and biology

authors： Newman DL,Dougherty G,al Obaid A,al Hajrasy H

更新日期：1998-03-01 00:00:00

abstract：:Ultrasound Doppler (UD) velocity measurements are commonly used to quantify blood flow velocities in vivo. The aim of our work was to investigate the accuracy of in vivo spectral Doppler measurements of velocity waveforms. Waveforms were derived from spectral Doppler signals and corrected for intrinsic spectral broade...

journal_title：Physics in medicine and biology

authors： Jiang J,Strother C,Johnson K,Baker S,Consigny D,Wieben O,Zagzebski J

更新日期：2011-03-21 00:00:00

abstract：:An alternative to gamma (gamma) histograms for ROI-based quantitative comparisons of dose distributions using the gamma concept is proposed. The method provides minimum values of dose difference and distance-to-agreement such that a pre-set fraction of the region of interest passes the gamma test. Compared to standard...

journal_title：Physics in medicine and biology

authors： Dvorak P

更新日期：2009-06-21 00:00:00

abstract：:A comprehensive set of measurements and calculations has been conducted to investigate the accuracy of the Dose Planning Method (DPM) Monte Carlo code for electron beam dose calculations in heterogeneous media. Measurements were made using 10 MeV and 50 MeV minimally scattered, uncollimated electron beams from a racet...

journal_title：Physics in medicine and biology

authors： Chetty IJ,Moran JM,Nurushev TS,McShan DL,Fraass BA,Wilderman SJ,Bielajew AF

更新日期：2002-06-07 00:00:00

abstract：:Kinetic parameters are commonly estimated from dynamically acquired nuclear medicine data by first reconstructing a dynamic sequence of images and subsequently fitting the parameters to time-activity curves generated from regions of interest overlaid upon the image sequence. Biased estimates can result from images rec...

journal_title：Physics in medicine and biology

authors： Huesman RH,Reutter BW,Zeng GL,Gullberg GT

更新日期：1998-04-01 00:00:00

abstract：:The derivative at constant direction is frequently used in inversion of cone-beam data. Several algorithms for computing the derivative have been proposed in the literature. The best algorithm to date has been proposed recently by Noo et al (2007 Phys. Med. Biol. 52 5393-414). In this note we propose a new, simple and...

journal_title：Physics in medicine and biology

authors： Katsevich A

更新日期：2011-02-21 00:00:00

abstract：:In this work, we propose a framework for optimizing spectral CT imaging parameters and hardware design with regard to material classification tasks. Compared with conventional CT, many more parameters must be considered when designing spectral CT systems and protocols. These choices will impact material classification...

journal_title：Physics in medicine and biology

authors： Rigie DS,La Rivière PJ

更新日期：2016-06-21 00:00:00

abstract：:In this study, an induced electric field in a human body is evaluated for the magnetic field leaked from a wireless power transfer system for charging an electrical vehicle. The magnetic field from the wireless power transfer system is modelled computationally, and its effectiveness is confirmed by comparison with the...

journal_title：Physics in medicine and biology

authors： Laakso I,Hirata A

更新日期：2013-11-07 00:00:00

abstract：:Beam hardening is inevitable due to the polychromatic X-ray spectrum and energy-dependent attenuation coefficients of materials, leading to the underestimation of artifacts arising from projection data, especially on metal regions. State-of-the-art research on beam-hardening artifacts is based on a numerical method th...

journal_title：Physics in medicine and biology

authors： Hur J,Kim D,Shin YG,Lee H

更新日期：2021-01-26 00:00:00

abstract：:The potential of the variable-aperture collimator (VAC) in intensity-modulated radiation therapy (IMRT) has been evaluated by comparing its performance with that of the multi-leaf collimator (MLC). This comparison used a decomposition algorithm to find the series of collimator segments that would treat a given intensi...

journal_title：Physics in medicine and biology

authors： Anderson JW,Symonds-Tayler R,Hartmann G,Echner G,Lang C,Schlegel W,Webb S

更新日期：2006-04-07 00:00:00

abstract：:Two novel materials have been developed to simulate the dielectric properties of human muscle and fat at 1000 MHz. These materials, which are based on ethanediol set with gelatine, are easily made and have good mechanical properties. The complex permittivity, epsilon *, of each material was measured with an open-ended...

journal_title：Physics in medicine and biology

authors： Robinson MP,Richardson MJ,Green JL,Preece AW

更新日期：1991-12-01 00:00:00

abstract：:Models of the electrical properties of biological tissue have been the subject of many studies. These models have sought to explain aspects of the dielectric dispersion of tissue. This paper develops a mathematical model of the complex permittivity of tissue as a function of frequency f, in the range 10(4) < f < 10(7)...

journal_title：Physics in medicine and biology

authors： Smye SW,Evans CJ,Robinson MP,Sleeman BD

更新日期：2007-12-07 00:00:00

abstract：:Two experimental investigations of the electromagnetic method to measure body composition are presented. In the first experiment, the impedance of a single-loop transmitting antenna, located at the centre of a 150 m helical receiving coil, was observed to have a sharp minimum at 2.40 MHz. The impedance of the antenna ...

journal_title：Physics in medicine and biology

authors： Sutcliffe JF,Smye SW,Smith MA

更新日期：1995-04-01 00:00:00

abstract：:Automatic cell cycle analysis (DNA histograms) is usually performed with flow cytometry. In cases when only few cells are available, the DNA content has to be measured with a fluorescence microscope combined with sensitive camera systems (SIT, MCP, cooled CCDs) and a frame grabber for image analysis. The fluorescent c...

journal_title：Physics in medicine and biology

authors： Böcker W,Gantenberg HW,Müller WU,Streffer C

更新日期：1996-03-01 00:00:00

abstract：:Incorrect prediction of skin dose in external beam radiotherapy (EBR) can have normal tissue complication such as acute skin desquamation and skin necrosis. The absorbed dose of skin should be evaluated within basal layer, placed between the epidermis and dermis layers. However, current treatment planning systems (TPS...

journal_title：Physics in medicine and biology

authors： Cheon BW,Yoo DH,Shin WG,Choi HJ,Park HJ,Kim JI,Min CH

更新日期：2019-08-14 00:00:00

abstract：:The color Doppler ultrasound twinkling artifact, which highlights kidney stones with rapidly changing color, has the potential to improve stone detection; however, its inconsistent appearance has limited its clinical utility. Recently, it was proposed stable crevice bubbles on the kidney stone surface cause twinkling;...

journal_title：Physics in medicine and biology

authors： Simon JC,Sapozhnikov OA,Kreider W,Breshock M,Williams JC,Bailey MR

更新日期：2018-01-09 00:00:00

abstract：:Cone-beam computed tomography (CBCT) has rapidly become a clinically useful imaging modality for image-guided radiation therapy. Unfortunately, CBCT images of the thorax are susceptible to artefacts due to scattered photons, beam hardening, lag in data acquisition, and respiratory motion during a slow scan. These limi...

journal_title：Physics in medicine and biology

authors： Disher B,Hajdok G,Wang A,Craig J,Gaede S,Battista JJ

更新日期：2013-06-21 00:00:00

abstract：:Four-dimensional volumetric modulated arc therapy (4D VMAT) is a treatment strategy for lung cancers that aims to exploit relative target and tissue motion to improve organ at risk (OAR) sparing. The algorithm incorporates the entire patient respiratory cycle using 4D CT data into the optimization process. Resulting t...

journal_title：Physics in medicine and biology

authors： Chin E,Loewen SK,Nichol A,Otto K

更新日期：2013-02-21 00:00:00

abstract：:Lung tumors treated in breath-hold are subject to inter- and intra-breath-hold variations, which makes tumor position monitoring during each breath-hold important. A markerless technique is desirable, but limited tumor visibility on kV images makes this challenging. We evaluated if template matching  +  triangulation ...

journal_title：Physics in medicine and biology

authors： Hazelaar C,Dahele M,Mostafavi H,van der Weide L,Slotman B,Verbakel W

更新日期：2018-05-29 00:00:00

abstract：:A modified sector-integration method is presented that can predict the output factors of irregular shaped electron fields even in the case of extended source to surface distance (SSD). The model takes as input measured output factors for circular inserts of various radii. These circular fields were measured at SSDs of...

journal_title：Physics in medicine and biology

authors： Choi DR,Wolters J,Mason D,Baillie A

更新日期：2000-11-01 00:00:00

abstract：:The interactions between energetic ions and biological and/or organic target materials have recently attracted theoretical and experimental attention, due to their implications for detector and device technologies, and for therapeutic applications. Most of the attention has focused on detection of the primary ionizati...

journal_title：Physics in medicine and biology

authors： Falzone N,Myhra S,Chakalova R,Hill MA,Thomson J,Vallis KA

更新日期：2013-11-07 00:00:00