Abstract:
:Novel methods are presented which allow the estimation of the effect of stereotactic fiducial marker localization on target localization in a stereotactic surgery planning program based on the integration of image data from various modalities. The results of simulations are presented. A method for the evaluation of the effect of fiducial marker localization error on stereotactic localization, both for computed tomography (CT) and digitized radiography. Is proposed based on perturbation studies. For tomographic data, the comparison of the stability of two types of fiducial localizers: a standard commercial device based on nine (six vertical and three oblique) rods and an imaginary system with an extra set of rods, called '4-N', is discussed. Results of the perturbation studies clearly indicate the necessity of sub-pixel registration of the fiducial markers in CT. On the other hand, results demonstrate that stereotactic localization based on projection images is less sensitive to fiducial localization error than CT. Finally, the authors present an algorithm for the localization of fiducial markers to sub-pixel accuracy in radiographs acquired with a commercial angio localizer.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Lemieux L,Jagoe Rdoi
10.1088/0031-9155/39/11/008subject
Has Abstractpub_date
1994-11-01 00:00:00pages
1915-28issue
11eissn
0031-9155issn
1361-6560journal_volume
39pub_type
杂志文章abstract::This study was carried out to investigate whether the electronic portal imaging (EPI) acquisition process could be optimized, and as a result tolerance and action levels be set for the PIPSPro QC-3V phantom image quality assessment. The aim of the optimization process was to reduce the dose delivered to the patient wh...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/52/23/006
更新日期:2007-12-07 00:00:00
abstract::Determining a multidimensional velocity field within microscale opaque fluid flows is needed in areas such as microfluidic devices, biofluid mechanics and hemodynamics research in animal studies. The ultrasonic particle image velocimetry (EchoPIV) technique is appropriate for measuring opaque flows by taking advantage...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/55/20/003
更新日期:2010-10-21 00:00:00
abstract::The authors have developed an apparatus able to generate ID intensity-modulated beams, using only one moving absorber within the irradiation field. A procedure for deriving optimized absorber-speed profiles in order to produce the desired fluence/dose profiles has been suggested. Experimental tests show that the syste...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/40/2/002
更新日期:1995-02-01 00:00:00
abstract::We have developed an iterative method to correct axial and tangential patient motion occurring during tomographic acquisition. The method uses axial images reconstructed from the uncorrected projection images, which are then forward projected to form a basis for registering the original planar images and, in the proce...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/43/1/011
更新日期:1998-01-01 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
pub_type: 杂志文章
doi:10.1088/1361-6560/ab1f29
更新日期:2019-09-05 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
pub_type: 杂志文章
doi:10.1088/1361-6560/ab3fd3
更新日期:2019-10-23 00:00:00
abstract::A method using both patient geometric and dosimetric information was proposed to predict dose-volume histograms (DVHs) of organs at risk (OARs) for a nasopharyngeal cancer (NPC) intensity-modulated radiation therapy (IMRT) plan. A total of 106 nine-field IMRT NPC plans were used in this study. Twenty-six plans were ra...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab50eb
更新日期:2019-12-05 00:00:00
abstract::Evidence that some lung tumors change shape during respiration is derived from respiratory gated CT data by statistical shape modeling and image manipulation. Some tumors behave as rigid objects while others show systematic shape changes. Two views of lung motion are presented to allow analysis of the results. In the ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/57/4/919
更新日期:2012-02-21 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
pub_type: 杂志文章
doi:10.1088/0031-9155/58/8/2491
更新日期:2013-04-21 00:00:00
abstract::Several direct algorithms have been proposed to take into account the non-linear path of protons in the reconstruction of a proton CT (pCT) image. This paper presents a comparison between five of them, in terms of spatial resolution and relative stopping power (RSP) accuracy. Our comparison includes (1) a distance-dri...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab7d53
更新日期:2020-06-01 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
pub_type: 杂志文章,多中心研究
doi:10.1088/0031-9155/50/9/003
更新日期:2005-05-07 00:00:00
abstract::Although the calculation of the surface average of the low-frequency current density distribution over a cross-section of 1 cm2 is required by ICNIRP guidelines, no reference averaging algorithm is indicated, neither in the ICNIRP guidelines nor in the Directive 2004/40/EC that is based on them. The lack of a general ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/54/15/013
更新日期:2009-08-07 00:00:00
abstract::Determination of the cardiorespiratory phase of the heart has numerous applications during cardiac imaging. In this article we propose a novel view-angle independent near-real time cardiorespiratory motion gating and coronary sinus (CS) catheter tracking technique for x-ray fluoroscopy images that are used to guide ca...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/60/20/8087
更新日期:2015-10-21 00:00:00
abstract::An experimental investigation of the central axis depth-dose and stopping rate distribution of the SIN biomedical pion beam is reported. The pion stopping rate in a thin disc of tissue-equivalent plastic was determined using a counter telescope. The dose rate at the position of this dic 'target' was measured using a s...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/22/3/007
更新日期:1977-05-01 00:00:00
abstract::Hair loss is a feared side effect of chemotherapy treatment. It may be prevented by cooling the scalp during administration of cytostatics. The supposed mechanism is that by cooling the scalp, both temperature and perfusion are diminished, affecting drug supply and drug uptake in the hair follicle. However, the effect...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/50/17/010
更新日期:2005-09-07 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
pub_type: 杂志文章
doi:10.1088/0031-9155/43/12/011
更新日期:1998-12-01 00:00:00
abstract::The use of deformable image registration methods in the context of adaptive radiotherapy leads to uncertainties in the simulation of the administered dose distributions during the treatment course. Evaluation of these methods is a prerequisite to decide if a plan adaptation will improve the individual treatment. Curre...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/aa69b6
更新日期:2017-06-21 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
pub_type: 杂志文章
doi:10.1088/0031-9155/54/4/013
更新日期:2009-02-21 00:00:00
abstract::To generate large thermal lesions in ultrasound thermal therapy, cooling intermissions are usually introduced during the treatment to prevent near-field heating, which leads to a long treatment time. A possible strategy to shorten the total treatment time is to eliminate the cooling intermissions. In this study, the t...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/48/9/307
更新日期:2003-05-07 00:00:00
abstract::Gold nanoparticle (GNP) radio-enhancement is a promising technique to increase the dose deposition in a tumor while sparing neighboring healthy tissue. Previous experimental studies showed effects on cell survival and tumor control for keV x-rays but surprisingly also for MV-photons, proton and carbon-ion beams. In a ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab314c
更新日期:2019-08-28 00:00:00
abstract::Scatter correction is a prerequisite for quantitative SPECT, but potentially increases noise. Monte Carlo simulations (EGS4) and physical phantom measurements were used to compare accuracy and noise properties of two scatter correction techniques: the triple-energy window (TEW), and the transmission dependent convolut...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/41/11/017
更新日期:1996-11-01 00:00:00
abstract::In fully three-dimensional PET imaging, iterative image reconstruction techniques usually outperform analytical algorithms in terms of image quality provided that an appropriate system model is used. In this study we concentrate on the calculation of an accurate system model for the YAP-(S)PET II small animal scanner,...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/58/19/6713
更新日期:2013-10-07 00:00:00
abstract::The imaging performance of a high-resolution preclinical micro-positron emission tomography (micro-PET) system employing liquid xenon (LXe) as the gamma-ray detection medium was simulated. The arrangement comprises a ring of detectors consisting of trapezoidal LXe time projection ionization chambers and two arrays of ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/57/6/1685
更新日期:2012-03-21 00:00:00
abstract::The measurand relevant for the dosimetry for radiation therapy is the absorbed dose to water, DW. The Physikalisch-Technische Bundesanstalt (PTB) is establishing a secondary standard for DW for high-energy photon and electron radiation based on electron spin resonance (ESR) of the amino acid alanine. For practical app...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/53/5/006
更新日期:2008-03-07 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
pub_type: 杂志文章
doi:10.1088/1361-6560/ab2144
更新日期:2019-06-05 00:00:00
abstract::The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, o...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/56/14/021
更新日期:2011-07-21 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
pub_type: 杂志文章
doi:10.1088/0031-9155/45/11/318
更新日期:2000-11-01 00:00:00
abstract::In this paper, the influence of a dynamic variation in the ambient pressure on the subharmonic response of phospholipid-coated microbubbles was investigated. The ambient pressure in water was modulated by a 2.5 kHz acoustic wave with a peak amplitude of 15 kPa. We investigated the fundamental and subharmonic emissions...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/56/19/018
更新日期:2011-10-07 00:00:00
abstract::Discrete implanted liver tumours in the rat have been exposed to arrays of 1.7 MHz ultrasound lesions. Focal peak intensities in the range 1.4-3.5 k Wcm-2 were used for an exposure time of 10 s. It has been demonstrated that where the whole tumour volume was exposed to the focused ultrasound beam, no evidence of tumou...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/36/11/009
更新日期:1991-11-01 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
pub_type: 杂志文章
doi:10.1088/0031-9155/54/9/009
更新日期:2009-05-07 00:00:00