Abstract：
:An electronic scanning-slit technology is under development which involves replacing paired fore and aft slits for scatter rejection with only one fore slit. As the slit scans across the portion of the patient to be imaged, pulsed x-ray exposures produce images of the slit in successive positions, which are digitized and stored in computer memory. Software techniques are used for tracking the slit image, and discriminating against scatter and veiling glare lying outside the slit image. Such "electronic collimation" does not require synchronization between the slit-scanning and detector readout, which makes it much simpler than alternative methods and potentially adaptable to any digital fluorography system. The performance characteristics of a prototype unit are described and images of a low-contrast phantom are presented.
journal_name
Med Physjournal_title
Medical physicsauthors
Plenkovich D,Sorenson JA,Kruger RAdoi
10.1118/1.595940subject
Has Abstractpub_date
1986-03-01 00:00:00pages
158-63issue
2eissn
0094-2405issn
2473-4209journal_volume
13pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:The assessment of differential left and right lung function is important for patients under consideration for lung resection procedures such as single lung transplantation. We developed an automated, knowledge-based segmentation algorithm for purposes of deriving functional information from dynamic computed tomography...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598898
更新日期：2000-03-01 00:00:00
abstract：:We applied Monte Carlo methods for the simulation of x-ray scattering in water phantoms. The phantom thickness was varied from 5 to 20 cm, and the monoenergetic incident x rays were varied from 15 to 100 keV. Eight screen pairs and a total absorption system were used as x-ray receptors. We determined the angular, spec...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595771
更新日期：1985-03-01 00:00:00
abstract：:The objective of this study was to compare the contrast-detail performance of five different commercial liquid crystal displays (LCDs) to other LCD and cathode-ray tube (CRT) displays for medical applications. A contrast-detail phantom, supplemented with 5 in. of acrylic, was imaged on a commercial digital radiographi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2868780
更新日期：2008-04-01 00:00:00
abstract：PURPOSE:The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET∕MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4757911
更新日期：2012-11-01 00:00:00
abstract：PURPOSE:Prostate cancer ranks as one of the most common malignancies and currently represents the second leading cancer-specific cause of death in men. The current use of single modality transrectal ultrasound (TRUS) for biopsy guidance has a limited sensitivity and specificity for accurately identifying cancerous lesi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4803498
更新日期：2013-06-01 00:00:00
abstract：:A photon transport algorithm for fully three-dimensional radiotherapy treatment planning has been developed based on the discrete ordinates (SN) solution of the Boltzmann equation. The algorithm is characterized by orthogonal adaptive meshes, which place additional points where large gradients occur and a procedure to...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2960247
更新日期：2008-09-01 00:00:00
abstract：:Knowledge of the relative intensity distribution at the patient's surface is essential for pencil beam calculations of three-dimensional dose distributions for arbitrarily shaped electron beams. To calculate the relative intensity distribution, the spatial spread resulting from angular spread is convolved with a two-d...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596252
更新日期：1988-03-01 00:00:00
abstract：PURPOSE:To overcome the problem of organ motion in intensity-modulated radiation therapy (IMRT), gated IMRT is often used for the treatment of lung cancer. In this study, the authors investigated the accuracy of the delivered monitor units (MUs) from each segment during gated IMRT using a two-dimensional detector array...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3310806
更新日期：2010-03-01 00:00:00
abstract：PURPOSE:To assess the image quality, scatter, and leakage radiation of an integrated magnetic resonance linear accelerator (MR-LINAC or MRL) system. METHODS:A large American College of Radiology (ACR) magnetic resonance imaging (MRI) accreditation phantom was used to evaluate the MRI capabilities of the integrated MRL...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12767
更新日期：2018-03-01 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：: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 ap...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1359245
更新日期：2001-04-01 00:00:00
abstract：:The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comf...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2179751
更新日期：2006-04-01 00:00:00
abstract：:Ultrasound contrast agents consist of microscopically small encapsulated bubbles that oscillate upon insonification. To enhance diagnostic ultrasound imaging techniques and to explore therapeutic applications, these medical microbubbles have been studied with the aid of high-speed photography. We filmed medical microb...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2133718
更新日期：2005-12-01 00:00:00
abstract：:The contribution of a commercially available diode matrix (MapCHECK, provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo (VMC++) algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3081414
更新日期：2009-04-01 00:00:00
abstract：:Intensity modulated radiation therapy (IMRT) is used to deliver highly conformal radiation doses to tumors while sparing nearby sensitive tissues. Discrepancies between calculated and measured dose distributions have been reported for regions of high dose gradients corresponding to complex radiation fluence patterns. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1812851
更新日期：2004-12-01 00:00:00
abstract：PURPOSE:A novel 3D printing method has been developed, which employs human CT images to construct patient specific phantoms by controlling the filament extrusion rate. METHODS:An in-house software was developed comprising pixel-by-pixel (PbP) reading of the Hounsfield Units (HU) values in the original patient DICOM im...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13154
更新日期：2018-10-01 00:00:00
abstract：PURPOSE:RapidArc is routinely used for stereotactic radiotherapy for lung cancer. While treatment dose is optimized and calculated on a static CT image, the motion of the target in conjunction with the motion of the MLC may Result in a delivered dose deviating from the planed dose. In this study, we investigate the dos...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734660
更新日期：2012-06-01 00:00:00
abstract：:As different types of radionuclides (e.g., 131Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2905356
更新日期：2008-06-01 00:00:00
abstract：PURPOSE:Intensity-modulated proton therapy (IMPT) is known to be sensitive to patient setup and range uncertainty issues. Multiple robust optimization methods have been developed to mitigate the impact of these uncertainties. Here, we propose a new robust optimization method, which provides an alternative way of robust...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13276
更新日期：2019-01-01 00:00:00
abstract：:Transthoracic electrical impedance Z consists of a constant baseline component Z0 and the time variable component delta Z such that Z = Z0 + delta Z. The first time derivative of Z has a negative peak, the magnitude of which is (dZ/dt)min. Measurements of 170 volunteers show that (dZ/dt)min is a function of the consta...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594910
更新日期：1981-01-01 00:00:00
abstract：PURPOSE:To apply the dual ionization chamber method for mixed radiation fields to an accurate comparison of the secondary neutron dose arising from the use of a tungsten alloy multileaf collimator (MLC) as opposed to a brass collimator system for defining the shape of a therapeutic proton field. METHODS:Hydrogenous an...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3656025
更新日期：2011-11-01 00:00:00
abstract：PURPOSE:Calculations of deoxyribonucleic acid (DNA) damages involve many parameters in the computation process. As these parameters are often subject to uncertainties, it is of central importance to comprehensively quantify their impacts on DNA single-strand break (SSB) and double-strand break (DSB) yields. This has be...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14036
更新日期：2020-04-01 00:00:00
abstract：:Automatic exposure control (AEC) systems have been developed by computed tomography (CT) manufacturers to improve the consistency of image quality among patients and to control the absorbed dose. Since a multichannel helical CT scan may easily increase individual radiation doses, this technical improvement is of speci...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2746492
更新日期：2007-07-01 00:00:00
abstract：PURPOSE:Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry o...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3524224
更新日期：2011-01-01 00:00:00
abstract：PURPOSE:A 3-year project called LABSYNC has been recently funded by the European Commission, with the aim of designing a radiation facility based on a compact light source, i.e., a laboratory-sized commercial synchrotron, capable of accelerating electrons up to 6 or 20 MeV. An accurate spectral description of hard x ra...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3223357
更新日期：2009-10-01 00:00:00
abstract：PURPOSE:To eliminate or reduce the error to Pareto optimality that arises in Pareto surface navigation when the Pareto surface is approximated by a small number of plans. METHODS:The authors propose to project the navigated plan onto the Pareto surface as a postprocessing step to the navigation. The projection attempt...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4930252
更新日期：2015-10-01 00:00:00
abstract：PURPOSE:To characterize a new air vented ionization chamber technology, suitable to build detector arrays with small pixel pitch and independence of sensitivity on dose per pulse. METHODS:The prototype under test is a linear array of air vented ionization chambers, consisting of 80 pixels with 3.5 mm pixel pitch dista...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4945414
更新日期：2016-05-01 00:00:00
abstract：PURPOSE:To find an upper bound on the maximum dose reduction possible for any reconstruction algorithm, analytic or iterative, that result from the inclusion of the data statistics. The authors do not analyze noise reduction possible from prior knowledge or assumptions about the object. METHODS:The authors examined th...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4941954
更新日期：2016-03-01 00:00:00
abstract：:Both the design considerations and the dosimetric properties of the Siemens Model 5800 linear accelerator are discussed. This unit is of such an energy (3.3 MV) as to imitate Cobalt-60 teletherapy depth doses. A linear relation of dmax to depth dose at low energies was found for various wave guides and targets. The en...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596487
更新日期：1990-05-01 00:00:00
abstract：:Complementary metal-oxide-semiconductors (CMOS) active pixel sensors can be optically coupled to CsI:Tl phosphors forming a indirect active pixel flat panel imager (APFPI) for high performance medical imaging. The aim of this work is to determine the x-ray imaging capabilities of CMOS-based APFPI and study the signal ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3036117
更新日期：2009-01-01 00:00:00
