Beam configurations for 3D tomographic intensity modulated radiation therapy.

abstract：:A stable cryogel dosimeter was prepared using ferrous benzoic xylenol orange (FBX) in a transparent poly-(vinyl alcohol) (PVA) cryogel matrix. Dose response was evaluated for different numbers of freeze-thaw cycles (FTCs), different concentrations of PVA, and ratios of water/dimethyl sulfoxide. Linear relationships be...

journal_title：Physics in medicine and biology

authors： Eyadeh MM,Farrell TJ,Diamond KR

更新日期：2014-04-07 00:00:00

abstract：:In this paper, we present a segmentation and classification method for thyroid follicular neoplasms based on a combination of the prior-based level set method and deep convolutional neural network. The proposed method aims to discriminate thyroid follicular adenoma (TFA) and follicular thyroid carcinoma (FTC) in ultra...

journal_title：Physics in medicine and biology

authors： Yang B,Yan M,Yan Z,Zhu C,Xu D,Dong F

更新日期：2020-11-02 00:00:00

abstract：:Fast heat extraction is critically important to obtain the maximal benefit of cryogen spray cooling (CSC) during laser therapy of shallow skin lesions, such as port wine stain birthmarks. However, a film of liquid cryogen can build up on the skin surface, impairing heat transfer due to the relatively low thermal condu...

journal_title：Physics in medicine and biology

authors： Majaron B,Svaasand LO,Aguilar G,Nelson JS

更新日期：2002-09-21 00:00:00

abstract：:A number of radiation-therapy-related uses based on a commercially available spreadsheet program have been developed at our facility. The graphics and display capabilities inherent in these spreadsheet programs allow for concise visual results. The spreadsheets are used as an independent check for several types of rad...

journal_title：Physics in medicine and biology

authors： Balog JP,Sibata CH,Podgorsak MB,Shin KH

更新日期：1995-06-01 00:00:00

abstract：:The trend towards conformal, intensity modulated radiotherapy treatments has established the need for a true integrating dosimeter. In traditional radiotherapy, radiographic film dosimetry is commonly used. The accuracy and reproducibility of film optical density as an indicator of dose is influenced by several variab...

journal_title：Physics in medicine and biology

authors： Suchowerska N,Hoban P,Butson M,Davison A,Metcalfe P

更新日期：2001-05-01 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：:At present, only a correction factor for photon transmission, k(l), is systematically applied for the entrance diaphragm of free-air chamber standards for air kerma. In the present work, the Monte Carlo code PENELOPE is used to re-evaluate k(l) for the BIPM standards and new correction factors are calculated for photo...

journal_title：Physics in medicine and biology

authors： Burns DT,Kessler C

更新日期：2009-05-07 00:00:00

abstract：:Treatment planning based on probability distribution function (PDF) of patient geometries has been shown a potential off-line strategy to incorporate organ motion, but the application of such approach highly depends upon the reproducibility of the PDF. In this paper, we investigated the dependences of the PDF reproduc...

journal_title：Physics in medicine and biology

authors： Cai J,Read PW,Altes TA,Molloy JA,Brookeman JR,Sheng K

更新日期：2007-01-21 00:00:00

abstract：:This is a proof of principle study on an algorithm for optimizing external beam radiotherapy in terms of both photon beamlet energy and fluence. This simultaneous beamlet energy and fluence optimization is denoted modulated photon radiotherapy (XMRT). XMRT is compared with single-energy intensity modulated radiotherap...

journal_title：Physics in medicine and biology

authors： McGeachy P,Villarreal-Barajas JE,Zinchenko Y,Khan R

更新日期：2016-02-21 00:00:00

abstract：:The optical properties (absorption and scattering coefficients and the scattering anisotropy factor) were measured in vitro for cartilage, liver, lung, muscle, myocardium, skin, and tumour (colon adenocarcinoma CC 531) at 630, 632.8, 790, 850 and 1064 nm. Rabbits, rats, piglets, goats, and dogs were used to obtain the...

journal_title：Physics in medicine and biology

authors： Beek JF,Blokland P,Posthumus P,Aalders M,Pickering JW,Sterenborg HJ,van Gemert MJ

更新日期：1997-11-01 00:00:00

abstract：:In stereotactic radiosurgery, a seven-irradiation film was used to define any discrepancy between the beam and target centres. A mathematical model based on the linac alignment and target set-up was developed to diagnose the discrepancies of the seven-irradiation film between the beam and simulation target centres. Fr...

journal_title：Physics in medicine and biology

authors： Tsai JS

更新日期：1996-09-01 00:00:00

abstract：:The treatment planning process for patients with head and neck (H&N) cancer is regarded as one of the most complicated due to large target volume, multiple prescription dose levels, and many radiation-sensitive critical structures near the target. Treatment planning for this site requires a high level of human experti...

journal_title：Physics in medicine and biology

authors： Nguyen D,Jia X,Sher D,Lin MH,Iqbal Z,Liu H,Jiang S

更新日期：2019-03-18 00:00:00

abstract：:Peripheral neural stimulation is a major problem in current gradient coil designs. Induced current problems in patients relate directly to gradient strength and modulation frequency. Present designs of gradient coil tend to limit ultra-high-speed imaging methods such as echo-planar imaging (EPI) and echo-volumar imagi...

journal_title：Physics in medicine and biology

authors： Mansfield P,Haywood B

更新日期：2008-04-07 00:00:00

abstract：:Image reconstruction of ultrasound computed tomography based on the wave equation is able to show much more structural details than simpler ray-based image reconstruction methods. However, to invert the wave-based forward model is computationally demanding. To address this problem, we develop an efficient fully learne...

journal_title：Physics in medicine and biology

authors： Zhao W,Wang H,Gemmeke H,van Dongen KWA,Hopp T,Hesser J

更新日期：2020-11-27 00:00:00

abstract：:Large blood vessels can produce steep temperature gradients in heated tissues leading to inadequate tissue temperatures during hyperthermia. This paper utilizes a finite difference scheme to solve the basic equations of heat transfer and fluid flow to model blood vessel cooling. Unlike previous formulations, heat tran...

journal_title：Physics in medicine and biology

authors： Kolios MC,Sherar MD,Hunt JW

更新日期：1995-04-01 00:00:00

abstract：:Diffusion weighted magnetic resonance imaging offers a non-invasive tool to explore the three-dimensional structure of brain white matter in clinical practice. Anisotropic diffusion hardware phantoms are useful for the quantitative validation of this technique. This study provides guidelines on how to manufacture anis...

journal_title：Physics in medicine and biology

authors： Fieremans E,De Deene Y,Delputte S,Ozdemir MS,Achten E,Lemahieu I

更新日期：2008-10-07 00:00:00

abstract：:A mathematical transcription of the intrinsic circuit of the CA1 region of the rat dorsal hippocampus was made and the model parameters adjusted according to experimental data from intracellular recordings and single channel kinetics. This model was able to simulate well the profile of the field potentials recorded ex...

journal_title：Physics in medicine and biology

authors： Almeida AC,Fernandes de Lima VM,Infantosi AF

更新日期：1998-09-01 00:00:00

abstract：:In dynamic renal scintigraphy, the main interest is the radiopharmaceutical redistribution as a function of time. Quality control (QC) of renal procedures often relies on phantom experiments to compare image-based results with the measurement setup. A phantom with a realistic anatomy and time-varying activity distribu...

journal_title：Physics in medicine and biology

authors： Brolin G,Gleisner KS,Ljungberg M

更新日期：2013-05-21 00:00:00

abstract：:The treatment delivery time of intensity-modulated radiation therapy (IMRT) with a multileaf collimator (MLC) is generally longer than that of conventional radiotherapy. In theory, removing the flattening filter from the treatment head may reduce the beam-on time by enhancing the output dose rate, and then reduce the ...

journal_title：Physics in medicine and biology

authors： Fu W,Dai J,Hu Y,Han D,Song Y

更新日期：2004-04-21 00:00:00

abstract：:Computer aided detection (CADe) for breast lesion can provide an important reference for radiologists in breast cancer screening. Architectural distortion (AD) is a type of breast lesion that is difficult to detect. A majority of CADe methods focus on detecting the radial pattern, which is a main characteristic of typ...

journal_title：Physics in medicine and biology

authors： Li Y,He Z,Lu Y,Ma X,Guo Y,Xie Z,Xu Z,Chen W,Chen H

更新日期：2020-06-02 00:00:00

abstract：:The aim of this study is to determine the impact of longitudinal micro-CT imaging on the growth of B16F1 tumours in C57BL/6 mice. Sixty mice received 2 × 10(5) B16F1 cells subcutaneously in the hind flank and were divided into control (no scan), 'low-dose' (80 kVp, 70 mA, 8 s, 0.07 Gy), 'medium-dose' (80 kVp, 50 mA, 3...

journal_title：Physics in medicine and biology

authors： Foster WK,Ford NL

更新日期：2011-01-21 00:00:00

abstract：:The purpose of this study is to calculate Pareto surfaces in multi-criteria radiation treatment planning and to analyse the dependency of the Pareto surfaces on the objective functions used for the volumes of interest. We develop a linear approach that allows us to calculate truly Pareto optimal treatment plans, and w...

journal_title：Physics in medicine and biology

authors： Craft D,Halabi T,Bortfeld T

更新日期：2005-12-21 00:00:00

abstract：:A number of heating sources are available for minimally invasive thermal therapy of tumours. The purpose of this work was to compare, theoretically, the heating characteristics of interstitial microwave, laser and ultrasound sources in three tissue sites: breast, brain and liver. Using a numerical method, the heating ...

journal_title：Physics in medicine and biology

authors： Skinner MG,Iizuka MN,Kolios MC,Sherar MD

更新日期：1998-12-01 00:00:00

abstract：:Dynamic radiation therapy techniques require that the treatment head setup varies in time and space during dose delivery. Examples are leaf motion in intensity modulated x-ray therapy, modulator wheel rotation in conventional proton therapy and variable magnet settings in proton beam scanning. Consequently, for Monte ...

journal_title：Physics in medicine and biology

authors： Paganetti H

更新日期：2004-03-21 00:00:00

abstract：:Quantitative assessment of mammographic asymmetry has been investigated for breast cancer risk prediction. A new asymmetry feature extraction method was proposed in this study to enhance the risk prediction accuracy of near-term breast cancer. Breast areas in each pair of bilateral mammographic images were divided int...

journal_title：Physics in medicine and biology

authors： Yan S,Zhang L,Song C

更新日期：2018-10-17 00:00:00

abstract：:Spinal screw placement is a challenging task due to small bone corridors and high risk of neurological or vascular complications, benefiting from precision guidance/navigation and quality assurance (QA). Implicit to both guidance and QA is the definition of a surgical plan-i.e. the desired trajectories and device sele...

journal_title：Physics in medicine and biology

authors： Goerres J,Uneri A,De Silva T,Ketcha M,Reaungamornrat S,Jacobson M,Vogt S,Kleinszig G,Osgood G,Wolinsky JP,Siewerdsen JH

更新日期：2017-04-07 00:00:00

abstract：:The 50-year tenure of Physics in Medicine and Biology has coincided with some of the most important developments in radiological science, including the introduction of artificial radioactivity, computers and 3D imaging into medicine. These events have profoundly influenced the development of brachytherapy. Although it...

journal_title：Physics in medicine and biology

authors： Williamson JF

更新日期：2006-07-07 00:00:00

abstract：:This work compared the impact of x-ray tube performance and automatic dose rate control (ADRC) parameter selection on system imaging efficiency of two Siemens angiography systems: a Siemens Megalix x-ray tube installed on an Artis Zee system (denoted 'MEGALIX') and a newer generation Gigalix x-ray tube installed on an...

journal_title：Physics in medicine and biology

authors： Dehairs M,Bosmans H,Marshall NW

更新日期：2020-11-24 00:00:00

abstract：:An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauteri...

journal_title：Physics in medicine and biology

authors： Umur A,van Gemert MJ,van den Wijngaard JP,Ross MG,Nikkels PG

更新日期：2004-07-21 00:00:00

abstract：:In robotic radiosurgery, it is necessary to compensate for systematic latencies arising from target tracking and mechanical constraints. This compensation is usually achieved by means of an algorithm which computes the future target position. In most scientific works on respiratory motion prediction, only one or two a...

journal_title：Physics in medicine and biology

authors： Ernst F,Dürichen R,Schlaefer A,Schweikard A

更新日期：2013-06-07 00:00:00