Assessment of the effects of pixel loss on image quality in direct digital radiography.

abstract：:Respiratory research with mice using micro-computed tomography (micro-CT) has been predominantly hindered by the limited resolution and signal-to-noise ratio (SNR) as a result of respiratory motion artefacts. In this study, we develop a novel technique for capturing the lung microstructure in vivo using micro-CT, thro...

journal_title：Physics in medicine and biology

authors： Namati E,Chon D,Thiesse J,Hoffman EA,de Ryk J,Ross A,McLennan G

更新日期：2006-12-07 00:00:00

abstract：:We couple standardized low-resolution electromagnetic tomography, an inverse solution for electroencephalography (EEG) and the common spatial pattern, which is here conceived as a data-driven beamformer, to classify the benchmark BCI (brain-computer interface) competition 2003, data set IV. The data set is from an exp...

journal_title：Physics in medicine and biology

authors： Congedo M,Lotte F,Lécuyer A

更新日期：2006-04-21 00:00:00

abstract：:Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry ...

journal_title：Physics in medicine and biology

authors： Afsharpour H,Landry G,D'Amours M,Enger S,Reniers B,Poon E,Carrier JF,Verhaegen F,Beaulieu L

更新日期：2012-06-07 00:00:00

abstract：:In proton therapy, the relative biological effectiveness (RBE) depends on various types of parameters such as linear energy transfer (LET). An analytical model for LET calculation exists (Wilkens' model), but secondary particles are not included in this model. In the present study, we propose a correction factor, L se...

journal_title：Physics in medicine and biology

authors： Marsolat F,De Marzi L,Pouzoulet F,Mazal A

更新日期：2016-01-21 00:00:00

abstract：:In BANG gel dosimetry, the spin-spin relaxation rate, R2 = I/T2, is related to the radiation dose that has been delivered to the gel phantom. R2 is calculated by fitting the pixel intensities of a set of differently T2-weighted base images. In gel dosimetry for radiotherapy, an accuracy of 5% in dose and 3 mm spatiall...

journal_title：Physics in medicine and biology

authors： De Deene Y,De Wagter C,De Neve W,Achten E

更新日期：2000-07-01 00:00:00

abstract：:This work modified the commonly used Monte Carlo tool package GATE by developing a new 'multiPatchPET' system so that GATE users can easily simulate PET systems with irregular geometries. The motivation was to design a brain PET scanner with high sensitivity. It is known that compact PET scanners with a large solid co...

journal_title：Physics in medicine and biology

authors： Chen G,Weng F,Hong X,Tao W,Zhao Z,Peng Q,Huang Q

更新日期：2018-09-06 00:00:00

abstract：:Dynamic 18F-FDG PET with tracer kinetic modeling has the potential to noninvasively evaluate human liver inflammation using the FDG blood-to-tissue transport rate K 1. Accurate kinetic modeling of dynamic liver PET data and K 1 quantification requires the knowledge of dual-blood input function from the hepatic artery ...

journal_title：Physics in medicine and biology

authors： Zuo Y,Sarkar S,Corwin MT,Olson K,Badawi RD,Wang G

更新日期：2019-09-05 00:00:00

abstract：:The purpose of this study is the analysis of the influence of anisotropic conductivity on magnetic fields and electric potentials by means of phantom measurements. An artificial rotating current dipole was placed in the middle of an anisotropic skein arrangement in a torso phantom filled with saline solution. The sign...

journal_title：Physics in medicine and biology

authors： Liehr M,Haueisen J

更新日期：2008-01-07 00:00:00

abstract：:The aim of this paper is to determine the dosimetric impact of trace elements in human tissues for low-energy photon sources used in brachytherapy. Monte Carlo dose calculations were used to investigate the dosimetric effect of trace elements present in normal or cancerous human tissues. The effect of individual trace...

journal_title：Physics in medicine and biology

authors： White SA,Landry G,van Gils F,Verhaegen F,Reniers B

更新日期：2012-06-07 00:00:00

abstract：:Successful radiotherapy treatment depends heavily upon the accuracy of patient geometry captured during treatment simulation using computed tomography (CT) scans. Radiotherapy patients are often scanned under free breathing, and respiratory motion can cause severe artifacts in CT scans, including shortening, elongatio...

journal_title：Physics in medicine and biology

authors： Lewis JH,Jiang SB

更新日期：2009-02-07 00:00:00

abstract：:Radiation therapy is an image-guided process whose success critically depends on the imaging modality used for treatment planning and the level of integration of the available imaging information. In this work, we establish a dose optimization framework for incorporating metabolic information from functional imaging m...

journal_title：Physics in medicine and biology

authors： Xing L,Cotrutz C,Hunjan S,Boyer AL,Adalsteinsson E,Spielman D

更新日期：2002-10-21 00:00:00

abstract：:A technique is presented to allow a breathing pattern to be obtained from any multi-slice CT, cone-beam or other series of sequential chest x-ray image sets. The technique requires no extra signals to be recorded and does not need specific external or internal oscillating structures to be visible in the field of view....

journal_title：Physics in medicine and biology

authors： Kavanagh A,Evans PM,Hansen VN,Webb S

更新日期：2009-08-21 00:00:00

abstract：:Dose calculations for radiation arc therapy are traditionally performed by approximating continuous delivery arcs with multiple static beams. For 3D conformal arc treatments, the shape and weight variation per degree is usually small enough to allow arcs to be approximated by static beams separated by 5 degrees -10 de...

journal_title：Physics in medicine and biology

authors： Tang G,Earl MA,Luan S,Wang C,Cao D,Yu CX,Naqvi SA

更新日期：2008-09-07 00:00:00

abstract：:The aim of the study is to determine PTV margin for inter-observer variability in the volumetric modulated arc therapy (VMAT) prostate radiotherapy with high-dose volumetric CT (HDVCT) and conventional helical CT (CCT) for planning. Secondly to investigate the impact of geometric (PTV expansion) and dosimetric (confor...

journal_title：Physics in medicine and biology

authors： Cho YB,Alasti H,Kong V,Catton C,Berlin A,Chung P,Bayley A,Jaffray D

更新日期：2019-03-14 00:00:00

abstract：:In digital breast tomosynthesis (DBT), image characteristics of projection views and reconstructed volume are different and both have the advantage of detecting breast masses, e.g. reconstructed volume mitigates a tissue overlap, while projection views have less reconstruction blur artifacts. In this paper, an improve...

journal_title：Physics in medicine and biology

authors： Kim DH,Kim ST,Ro YM

更新日期：2015-11-21 00:00:00

abstract：:All radiation therapy treatment planning relies on accurate dose calculation. Uncertainties in dosimetric prediction can significantly degrade an otherwise optimal plan. In this work, we introduce a robust optimization method which handles dosimetric errors and warrants for high-quality IMRT plans. Unlike other dose e...

journal_title：Physics in medicine and biology

authors： Nohadani O,Seco J,Martin BC,Bortfeld T

更新日期：2009-06-07 00:00:00

abstract：:We introduce a novel x-ray imaging approach that yields information about the local texture of structures smaller than the image pixel resolution inside an object. The approach is based on a recently developed x-ray dark-field imaging technique, using scattering from sub-micron structures in the sample. We show that t...

journal_title：Physics in medicine and biology

authors： Jensen TH,Bech M,Bunk O,Donath T,David C,Feidenhans'l R,Pfeiffer F

更新日期：2010-06-21 00:00:00

abstract：:Assessment of image quality for digital x-ray mammography systems used in European screening programs relies mainly on contrast-detail CDMAM phantom scoring and requires the acquisition and analysis of many images in order to reduce variability in threshold detectability. Part II of this study proposes an alternative ...

journal_title：Physics in medicine and biology

authors： Monnin P,Marshall NW,Bosmans H,Bochud FO,Verdun FR

更新日期：2011-07-21 00:00:00

abstract：:Two dosimetry protocols based on absorbed dose to water have recently been implemented: TG-51 and TRS-398. These protocols use different beam-quality indices: %dd(10)x and TPR20,10. The effect of electron contamination in measurements of %dd(10)x has been proposed as a disadvantage of the TG-51. For actual measurement...

journal_title：Physics in medicine and biology

authors： Lopez Medina A,Teijeiro A,Salvador F,Medal D,Vazquez J,Salgado M,Carrion MC

更新日期：2004-01-07 00:00:00

abstract：:The purpose of this paper for four-dimensional (4D) computed tomography (CT) is threefold. (1) A new spatiotemporal model is presented from the matrix perspective with the row dimension in space and the column dimension in time, namely the robust PCA (principal component analysis)-based 4D CT model. That is, instead o...

journal_title：Physics in medicine and biology

authors： Gao H,Cai JF,Shen Z,Zhao H

更新日期：2011-06-07 00:00:00

abstract：:We report the first experimental soft-tissue phase-contrast tomography results using a conventional x-ray tube source, with a millimeter-sized focal spot. The setup is based on a Talbot-Lau grating interferometer operated at a mean energy of 28 keV. We present three-dimensional ex vivo images of a chicken heart sample...

journal_title：Physics in medicine and biology

authors： Bech M,Jensen TH,Feidenhans'l R,Bunk O,David C,Pfeiffer F

更新日期：2009-05-07 00:00:00

abstract：:An overview of the theory of 4D image reconstruction for emission tomography is given along with a review of the current state of the art, covering both positron emission tomography and single photon emission computed tomography (SPECT). By viewing 4D image reconstruction as a matter of either linear or non-linear par...

journal_title：Physics in medicine and biology

authors： Reader AJ,Verhaeghe J

更新日期：2014-11-21 00:00:00

abstract：:A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is incorporated into a grow...

journal_title：Physics in medicine and biology

authors： Warman JM,de Haas MP,Luthjens LH

更新日期：2009-05-21 00:00:00

abstract：:In a previous paper the calibration of an isotropic light detector in clear media was described and validated. However, in most applications the detector is used to measure light distribution in turbid (scattering) media, that is, in tissues or tissue equivalent optical phantoms. Despite its small diameter (typically ...

journal_title：Physics in medicine and biology

authors： Marijnissen JP,Star WM

更新日期：2002-06-21 00:00:00

abstract：:Tumour histological grade has prognostic implications in breast cancer. Tumour features in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and T2-weighted (T2W) imaging can provide related and complementary information in the analysis of breast lesions to improve MRI-based histological status prediction...

journal_title：Physics in medicine and biology

authors： Fan M,Liu Z,Xie S,Xu M,Wang S,Gao X,Li L

更新日期：2019-10-23 00:00:00

abstract：:Accumulating evidence shows that hyperthermia improves head-and-neck cancer treatment. Over the last decade, we introduced a radiofrequency applicator, named HYPERcollar, which enables local heating also of deep locations in this region. Based on clinical experience, we redesigned the HYPERcollar for improved comfort,...

journal_title：Physics in medicine and biology

authors： Togni P,Rijnen Z,Numan WC,Verhaart RF,Bakker JF,van Rhoon GC,Paulides MM

更新日期：2013-09-07 00:00:00

abstract：:The purpose of this study was the evaluation of the impact of a variable relative biological effectiveness (RBE) compared to a constant RBE value of 1.1 in proton therapy prostate trials due to uncertainties in α/β ratio. Twenty patients receiving passive scattered proton therapy (PSPT) and fifteen patients receiving ...

journal_title：Physics in medicine and biology

authors： Marteinsdottir M,Paganetti H

更新日期：2019-06-05 00:00:00

abstract：:The High-Resolution Research Tomograph (HRRT) is a dedicated human brain positron emission tomography (PET) scanner. Recently, a 3D filtered backprojection (3D-FBP) reconstruction method has been implemented to reduce bias in short duration frames, currently observed in 3D ordinary Poisson OSEM (3D-OP-OSEM) reconstruc...

journal_title：Physics in medicine and biology

authors： van Velden FH,Kloet RW,van Berckel BN,Wolfensberger SP,Lammertsma AA,Boellaard R

更新日期：2008-06-21 00:00:00

abstract：:The aim of this work is to evaluate dosimetric accuracy of a new treatment modality, HybridArc, in iPlan RT Dose 4.5 (BrainLAB, Feldkirchen, Germany) using a four-dimensional diode array (ArcCHECK, Sun Nuclear Corporation, Melbourne, USA). HybridArc is able to enhance dynamic conformal arcs with inversely planned elem...

journal_title：Physics in medicine and biology

authors： Petoukhova AL,van Egmond J,Eenink MG,Wiggenraad RG,van Santvoort JP

更新日期：2011-08-21 00:00:00

abstract：:A new class of dose calibrator called a micro-dose calibrator, designed to measure radioactivity rates in the range between 1 kBq up to 370 kBq, has been designed and an 8 NaI(Tl)/photo multiplier tube (PMT) module prototype built to evaluate its performance. The design of the micro-dose calibrator is based on the con...

journal_title：Physics in medicine and biology

authors： Adler S,Choyke P

更新日期：2018-09-10 00:00:00