Accounting for range uncertainties in the optimization of intensity modulated proton therapy.

abstract：:Multileaf collimators (MLCs) have been in clinical use for many years and meanwhile are commonly used to deliver intensity-modulated radiotherapy (IMRT) beams. For this purpose it is important to know their dosimetric properties precisely, one of them being inter- and intraleaf leakage. The Siemens 160 MLC features a ...

journal_title：Physics in medicine and biology

authors： Klüter S,Sroka-Perez G,Schubert K,Debus J

更新日期：2011-01-21 00:00:00

abstract：:Beta emitting 106Ru-applicators are used to treat choroidal melanoma. In order to improve the accuracy and simplify the dosimetry of these applicators, the suitability of using a p-type silicon semiconductor detector has been investigated. The detector is calibrated in a low energy electron beam. An important property...

journal_title：Physics in medicine and biology

authors： Lax I

更新日期：1991-07-01 00:00:00

abstract：:A bilateral comparison of national dosimetric standards for high dose rate brachytherapy has been conducted between the Laboratoire National Henri Becquerel and the University of Wisconsin Accredited Dosimetry Calibration Laboratory. A complete overview of the methods that are currently in use to establish the two nat...

journal_title：Physics in medicine and biology

authors： Douysset G,Gouriou J,Delaunay F,DeWerd L,Stump K,Micka J,Laboratoire National Henri Becquerel.,University of Wisconsin Accredited Dosimetry Calibration Laboratory.

更新日期：2005-05-07 00:00:00

abstract：:Segmented attenuation correction is now a widely accepted technique to reduce noise propagation from transmission scanning in positron emission tomography (PET). In this paper, we present a new method for segmenting transmission images in whole-body scanning. This reduces the noise in the correction maps while still c...

journal_title：Physics in medicine and biology

authors： Zaidi H,Diaz-Gomez M,Boudraa A,Slosman DO

更新日期：2002-04-07 00:00:00

abstract：:Breast cancer is one of the leading causes of female cancer deaths. Early diagnosis with prophylactic may improve the patients' prognosis. So far ultrasound (US) imaging is a popular method in breast cancer diagnosis. However, its accuracy is bounded to traditional handcrafted feature methods and expertise. A novel me...

journal_title：Physics in medicine and biology

authors： Xie J,Song X,Zhang W,Dong Q,Wang Y,Li F,Wan C

更新日期：2020-10-29 00:00:00

abstract：:Compartmental models are widely used for the mathematical modelling of dynamic studies acquired with positron emission tomography (PET). The numerical problem involves the estimation of a sum of decaying real exponentials convolved with an input function. In exponential spectral analysis (SA), the nonlinear estimation...

journal_title：Physics in medicine and biology

authors： Turkheimer FE,Hinz R,Gunn RN,Aston JA,Gunn SR,Cunningham VJ

更新日期：2003-12-07 00:00:00

abstract：:Contrast-enhanced ultrasound (US) imaging is potentially applicable to the investigation of vascular disorders of the testis. We investigated the ability of two automated computer algorithms to analyse contrast-enhanced pulse inversion US data in a rabbit model of unilateral testicular ischaemia and to correctly deter...

journal_title：Physics in medicine and biology

authors： Thierman JS,Clement GT,Kalish LA,O'Kane PL,Frauscher F,Paltiel HJ

更新日期：2006-07-21 00:00:00

abstract：:Respiratory motion can blur the tomographic reconstruction of positron emission tomography or single-photon emission computed tomography (SPECT) images, which subsequently impair quantitative measurements, e.g. in the upper abdomen area. Respiratory signal phase-based gated reconstruction addresses this problem, but d...

journal_title：Physics in medicine and biology

authors： Breuilly M,Malandain G,Guglielmi J,Marsault R,Pourcher T,Franken PR,Darcourt J

更新日期：2013-04-21 00:00:00

abstract：:Many models exist for predicting toxicities based on dose-volume histograms (DVHs) or dose-surface histograms (DSHs). This approach has several drawbacks as firstly the reduction of the dose distribution to a histogram results in the loss of spatial information and secondly the bins of the histograms are highly correl...

journal_title：Physics in medicine and biology

authors： Buettner F,Gulliford SL,Webb S,Partridge M

更新日期：2011-04-07 00:00:00

abstract：:The aim of this study was to evaluate angiogenic compositions and tumour response in the course of neoadjuvant chemotherapy in patients with locally advanced breast cancer (LABC) using dynamic contrast-enhanced (DCE) MRI. Thirteen patients with LABC underwent serial DCE MRI during the course of chemotherapy. DCE MRI w...

journal_title：Physics in medicine and biology

authors： Chang YC,Huang CS,Liu YJ,Chen JH,Lu YS,Tseng WY

更新日期：2004-08-21 00:00:00

abstract：:Sparse-view CT reconstruction algorithms via total variation (TV) optimize the data iteratively on the basis of a noise- and artifact-reducing model, resulting in significant radiation dose reduction while maintaining image quality. However, the piecewise constant assumption of TV minimization often leads to the appea...

journal_title：Physics in medicine and biology

authors： Niu S,Gao Y,Bian Z,Huang J,Chen W,Yu G,Liang Z,Ma J

更新日期：2014-06-21 00:00:00

abstract：:Over the past few years there has been much interest in the development of three-dimensional dosimeters to determine the complex absorbed dose distribution in modern radiotherapy techniques such as IMRT and IGRT. In routine methods used for three-dimensional dosimetry, polymer gels are commonly used. Recently, a novel...

journal_title：Physics in medicine and biology

authors： Mostaar A,Hashemi B,Zahmatkesh MH,Aghamiri SM,Mahdavi SR

更新日期：2010-02-07 00:00:00

abstract：:Diffusion tensor tractography (DTT) allows one to explore axonal connectivity patterns in neuronal tissue by linking local predominant diffusion directions determined by diffusion tensor imaging (DTI). The majority of existing tractography approaches use continuous coordinates for calculating single trajectories throu...

journal_title：Physics in medicine and biology

authors： Bodammer NC,Kaufmann J,Kanowski M,Tempelmann C

更新日期：2009-02-21 00:00:00

abstract：:A technique is described by which the regional distribution of bone mineral can be determined in bone samples from small animals. The technique employs an Anger camera interfaced to a medical computer. High resolution (less than 1 mm) imaging is possible by producing magnified images of the bone samples. Regional dens...

journal_title：Physics in medicine and biology

authors： LeBlanc A,Evans H,Jhingran S,Johnson P

更新日期：1984-01-01 00:00:00

abstract：:For angiography using synchrotron radiation we measured the absorbed dose distribution in inhomogeneous phantoms with thin LiF:Mg, Cu, P, LiF:Mg, Ti thermoluminescent dosimeters (TLDs) in tissue and lung substitutes, and with Mg2SiO4:Tb TLDs in bone substitute for 33.32 keV monoenergetic photons from synchrotron radia...

journal_title：Physics in medicine and biology

authors： Nariyama N,Namito Y,Ban S,Hirayama H

更新日期：2001-03-01 00:00:00

abstract：:This work is dedicated to the reduction of reconstruction artefacts due to motion occurring during the acquisition of computerized tomographic projections. This problem has to be solved when imaging moving organs such as the lungs or the heart. The proposed method belongs to the class of motion compensation algorithms...

journal_title：Physics in medicine and biology

authors： Roux S,Desbat L,Koenig A,Grangeat P

更新日期：2004-06-07 00:00:00

abstract：:The objective of this paper is to evaluate an iterative maximum likelihood (ML) cone-beam computed tomography (CBCT) reconstruction with total variation (TV) regularization with respect to the robustness of the algorithm due to data inconsistencies. Three different and (for clinical application) typical classes of err...

journal_title：Physics in medicine and biology

authors： Stsepankou D,Arns A,Ng SK,Zygmanski P,Hesser J

更新日期：2012-10-07 00:00:00

abstract：:We explore how the radioactive background from naturally occurring 176Lu affects single photon transmission imaging for lutetium orthosilicate (LSO) scintillator-based PET cameras by estimating the transmission noise equivalent count rate (NECR) including this background. Assuming a typical PET camera geometry (80 cm ...

journal_title：Physics in medicine and biology

authors： Huber JS,Moses WW,Jones WF,Watson CC

更新日期：2002-10-07 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：:A water calorimeter has been used for the direct measurement of absorbed dose to water in a d(15) + Be neutron beam. The absorbed dose measured with the calorimeter was compared with that measured with an Exradin ionisation chamber, constructed of A-150 plastic. The doses measured by the ionisation chamber were calcul...

journal_title：Physics in medicine and biology

authors： Galloway G,Greening JR,Williams JR

更新日期：1986-04-01 00:00:00

abstract：:The aim of the study is to assess the staging value of the tumor heterogeneity characterized by texture features and other commonly used semi-quantitative indices extracted from (18)F-FDG PET images of cervical cancer (CC) patients. Forty-two patients suffering CC at different stages were enrolled in this study. First...

journal_title：Physics in medicine and biology

authors： Mu W,Chen Z,Liang Y,Shen W,Yang F,Dai R,Wu N,Tian J

更新日期：2015-07-07 00:00:00

abstract：:Conversion factors, which relate the kerma-area product to effective dose, have been estimated for paediatric cardiac x-ray angiography. Monte Carlo techniques have been used to calculate the conversion factors for a wide range of projection angles for children of five ages and for adults. Correction factors are provi...

journal_title：Physics in medicine and biology

authors： Schmidt PW,Dance DR,Skinner CL,Smith IA,McNeill JG

更新日期：2000-10-01 00:00:00

abstract：:A general theory is presented for minimizing noise in linear dimension reduction of sequences of medical images when the factors and the covariance matrix and mean of the noise are given. A dimension reduction is optimal when all diagonal elements in the covariance matrix of the noise in the signal (factor) space are ...

journal_title：Physics in medicine and biology

authors： Hermansen F,Lammertsma AA

更新日期：1995-11-01 00:00:00

abstract：:Dose calculations of pencil beam scanning treatment plans rely on the accuracy of proton spot profiles; not only the primary component but also the broad tail components. Four films are placed at several locations in air and multiple depths in Solidwater® for six selected energies. The films used for the primary compo...

journal_title：Physics in medicine and biology

authors： Lin L,Ainsley CG,McDonough JE

更新日期：2013-09-07 00:00:00

abstract：:This paper presents a compressed sensing (CS)-inspired reconstruction method for limited-angle computed tomography (CT). Currently, CS-inspired CT reconstructions are often performed by minimizing the total variation (TV) of a CT image subject to data consistency. A key to obtaining high image quality is to optimize t...

journal_title：Physics in medicine and biology

authors： Chen Z,Jin X,Li L,Wang G

更新日期：2013-04-07 00:00:00

abstract：:In this study we present a three-dimensional (3D) reconstruction algorithm for magneto-acoustic tomography with magnetic induction (MAT-MI) based on the characteristics of the ultrasound transducer. The algorithm is investigated to solve the blur problem of the MAT-MI acoustic source image, which is caused by the ultr...

journal_title：Physics in medicine and biology

authors： Ma R,Zhou X,Zhang S,Yin T,Liu Z

更新日期：2016-12-21 00:00:00

abstract：:A formalism is proposed for the estimation of mean glandular dose for breast tomosynthesis, which is a simple extension of the UK, European and IAEA protocols for dosimetry in conventional projection mammography. The formalism introduces t-factors for the calculation of breast dose from a single projection and T-facto...

journal_title：Physics in medicine and biology

authors： Dance DR,Young KC,van Engen RE

更新日期：2011-01-21 00:00:00

abstract：:A comparative study was performed to reveal differences and relative figures of merit of seven different calculation algorithms for photon beams when applied to inhomogeneous media. The following algorithms were investigated: Varian Eclipse: the anisotropic analytical algorithm, and the pencil beam with modified Batho...

journal_title：Physics in medicine and biology

authors： Fogliata A,Vanetti E,Albers D,Brink C,Clivio A,Knöös T,Nicolini G,Cozzi L

更新日期：2007-03-07 00:00:00

abstract：:We used a real-skull phantom head to investigate the performances of representative methods for EEG source localization when considering various head models. We describe several experiments using a montage with current sources located at multiple positions and orientations inside a human skull filled with a conductive...

journal_title：Physics in medicine and biology

authors： Baillet S,Riera JJ,Marin G,Mangin JF,Aubert J,Garnero L

更新日期：2001-01-01 00:00:00

abstract：:For proton therapy, an accurate conversion of CT HU to relative stopping power (RSP) is essential. Validation of the conversion based on real tissue samples is more direct than the current practice solely based on tissue substitutes and can potentially address variations over the population. Based on a novel dose exti...

journal_title：Physics in medicine and biology

authors： Zhang R,Baer E,Jee KW,Sharp GC,Flanz J,Lu HM

更新日期：2017-06-23 00:00:00