Abstract：
:We report on some extensions and further developments of a well-known microcalcification detection algorithm based on adaptive noise equalization. Tissue equivalent phantom images with and without labeled microcalcifications were subjected to this algorithm, and analyses of results revealed some shortcomings in the approach. Particularly, it was observed that the method of estimating the width of distributions in the feature space was based on assumptions which resulted in the loss of similarity preservation characteristics. A modification involving a change of estimator statistic was made, and the modified approach was tested on the same phantom images. Other modifications for improving detectability such as downsampling and use of alternate local contrast filters were also tested. The results indicate that these modifications yield improvements in detectability, while extending the generality of the approach. Extensions to real mammograms and further directions of research are discussed.
journal_name
Med Physjournal_title
Medical physicsauthors
Gürün OO,Fatouros PP,Kuhn GM,de Paredes ESdoi
10.1118/1.1359245subject
Has Abstractpub_date
2001-04-01 00:00:00pages
445-54issue
4eissn
0094-2405issn
2473-4209journal_volume
28pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:Topographic treatment is a radiation therapy delivery technique for fixed-gantry (nonrotational) treatments on a helical tomotherapy system. The intensity-modulated fields are created by moving the treatment couch relative to a fan-beam positioned at fixed gantry angles. The delivered dose distribution is controlled b...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2216876
更新日期：2006-08-01 00:00:00
abstract：:An optimization analysis of digital fluoroscopy has been carried out using (signal/noise)2/dose as a figure of merit. Three signal detection tasks have been considered: (i) small iodine-containing blood vessels; (ii) regions of fat; and (iii) microcalcifications. The effects of x-ray beam filtration and kilovoltage on...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595130
更新日期：1982-09-01 00:00:00
abstract：:The wall of an ionization chamber is commonly assumed to have a negligible effect on chamber response in electron beams. For cylindrical chambers with thin walls this assumption is valid. However, parallel-plate chambers commonly possess large mechanical supports which may affect chamber response in a manner not accou...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596165
更新日期：1988-01-01 00:00:00
abstract：PURPOSE:The aim of this study was to evaluate the suitability of several detectors for the determination of absorbed dose in bone. METHODS:Three types of ultrathin LiF-based thermoluminescent dosimeters (TLDs)-two LiF:Mg,Cu,P-based (MCP-Ns and TLD-2000F) and a (7)Li-enriched LiF:Mg,Ti-based (MTS-7s)-as well as EBT2 Ga...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4886760
更新日期：2014-08-01 00:00:00
abstract：PURPOSE:Talbot-Lau x-ray interferometry provides information about the scattering and refractive properties of an object - in addition to the object's attenuation features. Until recently, this method was ineligible for imaging human-sized objects as it is challenging to adapt Talbot-Lau interferometers (TLIs) to the r...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12889
更新日期：2018-06-01 00:00:00
abstract：PURPOSE:The study aims to investigate whether Nakagami parameters--estimated from the statistical distribution of the backscattered ultrasound radio-frequency (RF) signals--could provide a means for quantitative characterization of parotid-gland injury resulting from head-and-neck radiotherapy. METHODS:A preliminary c...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4862507
更新日期：2014-02-01 00:00:00
abstract：:Multielectrode cochlear implantation is the most effective treatment for profound sensorineural hearing loss. In vivo three-dimensional 3-D localization of cochlear implant electrodes is important for modeling of the electrical field in the cochlea, design of electrode arrays, and may improve speech processor programm...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598940
更新日期：2000-04-01 00:00:00
abstract：PURPOSE:The authors investigate performance of thin-film cadmium telluride (CdTe) in detecting high-energy (6 MV) x rays. The utilization of this material has become technologically feasible only in recent years due to significant development in large area photovoltaic applications. METHODS:The CdTe film is combined w...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3438082
更新日期：2010-08-01 00:00:00
abstract：:The assessment of the radiation dose to internal organs or to an embryo or fetus is required on occasion for risk assessment or for comparing imaging studies. Limited resources hinder the ability to accurately assess the radiation dose received to locations outside the tissue volume actually scanned during computed to...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1312809
更新日期：2000-10-01 00:00:00
abstract：PURPOSE:Power spectral analysis in radiographic images is conventionally performed using a windowed overlapping averaging periodogram. This study describes an alternative approach using a multitaper technique and compares its performance with that of the standard method. This tool will be valuable in power spectrum est...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3676740
更新日期：2012-02-01 00:00:00
abstract：:A computed tomography (CT) based system that compensates for patient surface contour and internal tissue inhomogeneity was implemented in our clinic. The compensators are fabricated with a mixture of tin granules and bee's wax. The tin/wax mixture was optimized for tin granule size and tin granule to wax ratio. The na...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597303
更新日期：1994-03-01 00:00:00
abstract：:Administration of x-ray contrast agents during heart catheterization examination increases the absorbed radiation dose in tissue. To estimate the dose absorbed by the blood of children undergoing diagnostic heart catheterization and angiocardiography, a number of measurements and calculations were conducted. First, en...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594613
更新日期：1979-11-01 00:00:00
abstract：PURPOSE:Radiochromic film provides dose measurement at high spatial resolution, but often is not preferred for routine evaluation of patient-specific intensity modulated radiation therapy (IMRT) plans owing to ease-of-use factors. The authors have established an efficient protocol that combines calibration and measurem...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4754797
更新日期：2012-10-01 00:00:00
abstract：PURPOSE:In this study, the authors validated a novel respiratory tracking device, the multidimensional respiratory tracking (MDRT) system, that was designed to assist in correcting for respiratory motion in PET/CT images. The authors also investigated a novel PET acquisition technique, smart gating (SG), that enables t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3523100
更新日期：2011-01-01 00:00:00
abstract：:An energy discriminating detector for dual-energy radiography can be configured as a two-layer sandwich, where the mean energy of photons detected by the two layers differs. To characterize the quantum noise of such a detector, the noise covariance between the two layers must be known in addition to the noise variance...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596311
更新日期：1989-11-01 00:00:00
abstract：:Over the past decade, computed tomography (CT) theory, techniques and applications have undergone a rapid development. Since CT is so practical and useful, undoubtedly CT technology will continue advancing biomedical and non-biomedical applications. In this outlook article, we share our opinions on the research and de...
journal_title：Medical physics
pub_type： 杂志文章,评审
doi：10.1118/1.2836950
更新日期：2008-03-01 00:00:00
abstract：:Model-based deformable organ registration techniques using the finite element method (FEM) have recently been investigated intensively and applied to image-guided adaptive radiotherapy (IGART). These techniques assume that human organs are linearly elastic material, and their mechanical properties are predetermined. U...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2163838
更新日期：2006-02-01 00:00:00
abstract：PURPOSE:X-ray fluorescence computer tomography (XFCT) is a new molecular imaging modality which uses x-ray excitation to stimulate the emission of fluorescent photons in high atomic number contrast agents. Scatter contamination is one of the main challenges in XFCT imaging which limits the molecular sensitivity. When p...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12997
更新日期：2018-05-25 00:00:00
abstract：:This study proposes an algorithm for selecting beam weight, wedge angle, and wedge orientation for three-dimensional radiation therapy treatment planning. According to dose gradient analysis, the necessary and sufficient condition for achieving a homogeneous dose over the target volume is that the total vector sum of ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1286591
更新日期：2000-08-01 00:00:00
abstract：PURPOSE:To develop an automated treatment planning strategy for external beam intensity-modulated radiation therapy (IMRT), including a deep learning-based three-dimensional (3D) dose prediction and a dose distribution-based plan generation algorithm. METHODS AND MATERIALS:A residual neural network-based deep learning...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13271
更新日期：2019-01-01 00:00:00
abstract：:The paper presents a theoretical derivation of the photon fluence simulation efficiency in photon beam treatment head simulations without and with bremsstrahlung splitting. The expressions obtained provide a rigorous explanation of the efficiency dependence on scoring zone size and splitting number and explain the lar...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1943808
更新日期：2005-07-01 00:00:00
abstract：:Modern linear accelerators contain multiple isocentres, defined by the mechanical motions of gantry, collimator and table. Isocentre localization for these motions has been performed using film and manual evaluations which have difficulty in relating the individual motions. To address these limitations, we have develo...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2965950
更新日期：2008-07-01 00:00:00
abstract：PURPOSE:To use Cone Beam CT scans obtained just prior to treatments of head and neck cancer patients to measure the setup error and cumulative dose uncertainty of the cochlea. METHODS:Data from 10 head and neck patients with 10 planning CTs and 52 Cone Beam CTs taken at time of treatment were used in this study. Patie...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4830427
更新日期：2013-12-01 00:00:00
abstract：:Testing computer-controlled linear accelerators for patient safety and proper patient dose delivery requires that certain beam characteristics be monitored over an extended period of time. Computer-controlled conformal radiation therapy using asymmetric collimator jaw settings necessitates stable symmetric treatment b...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596363
更新日期：1989-07-01 00:00:00
abstract：PURPOSE:In order to build up a reliable dose monitoring system for boron neutron capture therapy (BNCT) applications at the TRIGA reactor in Mainz, a computer model for the entire reactor was established, simulating the radiation field by means of the Monte Carlo method. The impact of different source definition techni...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4897242
更新日期：2014-11-01 00:00:00
abstract：:Extensive information has been made available relative to the physical aspects necessary for calculation of radiation absorbed dose from radiopharmaceuticals. A similar data base for the biological factors involved in these calculations has not been documented as thoroughly. The authors present an extensive literature...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594679
更新日期：1980-05-01 00:00:00
abstract：PURPOSE:Real-time sub-millimeter head motion compensation during frameless SRS delivery has the potential to achieve the accuracy of frame-based SRS while being significantly less invasive. Previously, we demonstrated real-time 6D head motion monitoring using an optical camera, however, at the time we were limited to o...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734995
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Very fast Monte Carlo (MC) simulations of proton transport have been implemented recently on graphics processing units (GPUs). However, these MCs usually use simplified models for nonelastic proton-nucleus interactions. Our primary goal is to build a GPU-based proton transport MC with detailed modeling of elast...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4921046
更新日期：2015-06-01 00:00:00
abstract：:Imaging of radiation dose distribution in gel phantoms by magnetic resonance techniques has previously been reported. In this paper a method of producing gels in which the distributions of radiation dose can also be visualized as a color change is reported. The color developed depends qualitatively and quantitatively ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596676
更新日期：1991-03-01 00:00:00
abstract：:The objective of this work is to assess the suitability and performance of a new dosimeter system with a novel geometry for the quality assurance (QA) of volumetric modulated arc therapy (VMAT). The new dosimeter system consists of a hollow cylinder (15 and 25 cm inner and outer diameters) with 124 diodes embedded in ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3117563
更新日期：2009-05-01 00:00:00
