Scatter-glare correction using a convolution algorithm with variable weighting.

abstract：:A computationally efficient pseudodynamical filtering setup is established for elasticity imaging (i.e., reconstruction of shear modulus distribution) in soft-tissue organs given statically recorded and partially measured displacement data. Unlike a regularized quasi-Newton method (QNM) that needs inversion of ill-con...

journal_title：Medical physics

authors： Banerjee B,Roy D,Vasu RM

更新日期：2009-08-01 00:00:00

abstract：PURPOSE:Ultrasound-induced mild hyperthermia has advantages for noninvasive, localized and controlled drug delivery. In this study, a tissue-mimicking agarose-based phantom with a thermally sensitive indicator was developed for studying the spatial drug delivery profile using ultrasound-induced mild hyperthermia. METH...

journal_title：Medical physics

authors： Lai CY,Kruse D,Seo JW,Kheirolomoom A,Ferrara KW

更新日期：2013-08-01 00:00:00

abstract：PURPOSE:The purpose of this paper was to present a method of determining the dose profile of the beam bow-tie filter (BTF) without the need for fixing the x ray tube in a position or using special instruments or dosimeters other than the ordinary types of ion chambers used for CT dosimetry (e.g., Farmer chamber). METH...

journal_title：Medical physics

authors： Al-Senan R

更新日期：2018-11-01 00:00:00

abstract：:The purpose of this work is to demonstrate a proof of feasibility of the application of a commercial prototype deformable model algorithm to the problem of delineation of anatomic structures on four-dimensional (4D) computed tomography (CT) image data sets. We acquired a 4D CT image data set of a patient's thorax that...

journal_title：Medical physics

authors： Ragan D,Starkschall G,McNutt T,Kaus M,Guerrero T,Stevens CW

更新日期：2005-07-01 00:00:00

abstract：:A very important issue in contemporary inverse treatment radiotherapy planning is the specification of proper dose-volume constraints limiting the treatment planning algorithm from delivering high doses to the normal tissue surrounding the tumor. Recently we have proposed a method called reverse mapping of normal tiss...

journal_title：Medical physics

authors： Markov K,Schinkel C,Stavreva N,Stavrev P,Weldon M,Fallone BG

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:Automatic breast ultrasound (ABUS) imaging has become an essential tool in breast cancer diagnosis since it provides complementary information to other imaging modalities. Lesion segmentation on ABUS is a prerequisite step of breast cancer computer-aided diagnosis (CAD). This work aims to develop a deep learnin...

journal_title：Medical physics

authors： Lei Y,He X,Yao J,Wang T,Wang L,Li W,Curran WJ,Liu T,Xu D,Yang X

更新日期：2020-10-30 00:00:00

abstract：PURPOSE:Current respiratory motion monitoring devices used for motion synchronization in medical imaging and radiotherapy provide either 1D respiratory signal over a specific region or 3D information based on few external or internal markers. On the other hand, newer technology may offer the potential to monitor the en...

journal_title：Medical physics

authors： Fayad H,Pan T,Clement JF,Visvikis D

更新日期：2011-06-01 00:00:00

abstract：:Two new liquid ionization chamber (LIC) designs, consisting of cylindrical and plane-parallel configurations, are presented. They are designed to be suitable for high-precision measurements of absorbed dose-to-water at dose rates and photon energies typical for LDR intermediate photon energy brachytherapy sources. The...

journal_title：Medical physics

authors： Wickman G,Johansson B,Bahar-Gogani J,Holmström T,Grindborg JE

更新日期：1998-06-01 00:00:00

abstract：PURPOSE:X-ray phase-contrast tomography (PCT) is a rapidly emerging imaging modality for reconstructing estimates of an object's three-dimensional x-ray refractive index distribution. Unlike conventional x-ray computed tomography methods, the statistical properties of the reconstructed images in PCT remain unexplored. ...

journal_title：Medical physics

authors： Chou CY,Anastasio MA

更新日期：2010-01-01 00:00:00

abstract：:The physical characteristics of the interactions of megavoltage photons and electrons with matter provide distinct advantages, relative to low-energy (orthovoltage) x rays, that lead to better radiation dose distributions in patients. Use of these high-energy radiations has resulted in better patient care, which has b...

journal_title：Medical physics

authors： Das IJ,Kase KR

更新日期：1992-07-01 00:00:00

abstract：:Our purpose in this work was to assess the reliability of the calibration coefficient for magnetic resonance water proton chemical shift temperature mapping. Over a six month period, the calibration coefficient was measured 15 times in several different phantoms. A highly linear relationship between water proton chemi...

journal_title：Medical physics

authors： Wu T,Kendell KR,Felmlee JP,Lewis BD,Ehman RL

更新日期：2000-01-01 00:00:00

abstract：PURPOSE:High-Z material in computed tomography (CT) yields metal artifacts that degrade image quality and may cause substantial errors in dose calculation. This study couples a metal artifact reduction (MAR) algorithm with enhanced 16-bit depth (vs standard 12-bit) to quantify potential gains in image quality and dosim...

journal_title：Medical physics

authors： Glide-Hurst C,Chen D,Zhong H,Chetty IJ

更新日期：2013-06-01 00:00:00

abstract：PURPOSE:We propose a new method for efficient particle transportation in voxelized geometry for Monte Carlo simulations. We describe its use for calculating dose distribution in CT images for radiation therapy. MATERIAL AND METHODS:The proposed approach, based on an implicit volume representation named segmented volum...

journal_title：Medical physics

authors： Sarrut D,Guigues L

更新日期：2008-04-01 00:00:00

abstract：PURPOSE:As the predominant driver of respiratory motion, the diaphragm represents a key surrogate for motion management during the irradiation of thoracic cancers. Existing approaches to diaphragm tracking often produce phase-based estimates, suffer from lateral side failures or are not executable in real-time. In this...

journal_title：Medical physics

authors： Hindley N,Keall P,Booth J,Shieh CC

更新日期：2019-10-01 00:00:00

abstract：:A new high-resolution detector has been developed for use in a slot-scanned digital mammography system. The detector is a hybrid device that consists of a CCD operating in time-delay integration mode that is bonded to a 150-microm-thick CdZnTe photoconductor array. The CCD was designed with a detector element pitch of...

journal_title：Medical physics

authors： Mainprize JG,Ford NL,Yin S,Gordon EE,Hamilton WJ,Tümer TO,Yaffe MJ

更新日期：2002-12-01 00:00:00

abstract：:The visual observer performance for detecting low-contrast patterns by employing both the receiver operating characteristic (ROC) and the 9-alternative forced choice (9-AFC) method is investigated. For each observer and each experimental technique, the results were reproducible with respect to a repeated observation. ...

journal_title：Medical physics

authors： Herrmann C,Buhr E,Hoeschen D,Fan SY

更新日期：1993-05-01 00:00:00

abstract：PURPOSE:The authors introduce a novel method for defining standardized uptake values (SUVs) in PET∕CT based on routinely collected CT data. The goal of the study is to reduce, if possible, the variability of SUV in a heterogeneous population. Two well established methods for defining SUV are based on body weight (BW) a...

journal_title：Medical physics

authors： Hamill JJ,Sunderland JJ,LeBlanc AK,Kojima CJ,Wall J,Martin EB

更新日期：2013-09-01 00:00:00

abstract：:Due to practical limitations in data acquisition, 3-D computed tomography systems must attempt to provide rapid reconstructions of acceptable quality from a limited number of views. The use of convolution backprojection (CBP) for image reconstruction from an inadequate number of projections, results in view aliasing a...

journal_title：Medical physics

authors： Galigekere RR,Wiesent K,Holdsworth DW

更新日期：1999-06-01 00:00:00

abstract：PURPOSE:Periodic MV∕KV radiographs taken during volumetric modulated arc therapy (VMAT) for hypofractionated treatment provide guidance in intrafractional motion management. The choice of imaging frequency and timing are key components in delivering the desired dose while reducing associated overhead such as imaging do...

journal_title：Medical physics

authors： Zhang P,Hunt M,Happersett L,Cox B,Mageras G

更新日期：2012-09-01 00:00:00

abstract：:In order to investigate the relationship between diagnostic accuracy and radiographic image quality, we have developed a dual-film cassette which produces two radiographs simultaneously with a single exposure. One of these radiographs is of standard quality; the second is of lower quality because of degraded spatial r...

journal_title：Medical physics

authors： Higashida Y,Doi K,Lehr JL,MacMahon H

更新日期：1984-09-01 00:00:00

abstract：:A commercial optical system developed by Solid Photography, Inc., has been used to generate precise paraffin--polyethylene tissue compensators. A program with the objective of constructing a medical facility has been undertaken to access patient topology for treatment planning, tissue-compensator fabrication, and pati...

journal_title：Medical physics

authors： Lerch IA,Barish RJ,Stern H

更新日期：1978-11-01 00:00:00

abstract：:Like Medical Physics, Imaging Informatics encompasses concepts touching every aspect of the imaging chain from image creation, acquisition, management and archival, to image processing, analysis, display and interpretation. The two disciplines are in fact quite complementary, with similar goals to improve the quality ...

journal_title：Medical physics

authors： Andriole K

更新日期：2012-06-01 00:00:00

abstract：:Total scalp irradiation is a treatment technique used for a variety of superficial malignancies. Helical tomotherapy is an effective technique used for total scalp irradiation. Recent published work has shown the TomoTherapy planning system to overestimate the superficial dose. In this study, the superficial doses for...

journal_title：Medical physics

authors： Hardcastle N,Soisson E,Metcalfe P,Rosenfeld AB,Tome WA

更新日期：2008-11-01 00:00:00

abstract：:The surface radio frequency (rf) power absorption in human head and torso nuclear magnetic resonance (NMR) imaging experiments is estimated. The results are expressed as a function of the NMR frequency, the rf pulse length, and the pulse duty cycle, which are varied over six orders of magnitude for general applicabili...

journal_title：Medical physics

authors： Bottomley PA,Edelstein WA

更新日期：1981-07-01 00:00:00

abstract：PURPOSE:Deformable registration generally relies on the assumption that the sought spatial transformation is smooth. Yet, breathing motion involves sliding of the lung with respect to the chest wall, causing a discontinuity in the motion field, and the smoothness assumption can lead to poor matching accuracy. In respon...

journal_title：Medical physics

authors： Vandemeulebroucke J,Bernard O,Rit S,Kybic J,Clarysse P,Sarrut D

更新日期：2012-02-01 00:00:00

abstract：:It is shown that in narrow monoenergetic photon beams under conditions of lateral electron disequilibrium, primary absorbed dose P(r) is a simple function of beam radius r: P(r) = P lambda.(1 - e(-gamma.r)), where P lambda is the primary dose in broad beams for which complete lateral electron equilibrium exists, and g...

journal_title：Medical physics

authors： Nizin PS,Chang XS

更新日期：1991-07-01 00:00:00

abstract：PURPOSE:The spatial and temporal tracking performance of a commercially available 3D optical surface imaging system is evaluated for its potential use in frameless stereotactic radiosurgery head tracking applications. METHODS:Both 3D surface and infrared (IR) marker tracking were performed simultaneously on a head pha...

journal_title：Medical physics

authors： Wiersma RD,Tomarken SL,Grelewicz Z,Belcher AH,Kang H

更新日期：2013-11-01 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

authors： Vernekohl D,Tzoumas S,Zhao W,Xing L

更新日期：2018-05-25 00:00:00

abstract：:In prostate seed implants, radioactive seeds are implanted into the prostate through a guiding needle with the help of a template and real-time imaging. The ideal locations of the guiding needles and the relative positions of the seeds in each needle are determined before the implantation under the assumption that the...

journal_title：Medical physics

authors： Nath S,Chen Z,Yue N,Trumpore S,Peschel R

更新日期：2000-05-01 00:00:00

abstract：PURPOSE:Brachytherapy is a treatment modality which delivers large doses of radiation in a reduced number of visits. Since a small number of large dose-per-fraction is administered in high dose rate brachytherapy, ensuring the right dose is delivered is highly critical. In this work, a scintillation detector is coupled...

journal_title：Medical physics

authors： Tho D,Beaulieu L

更新日期：2019-05-01 00:00:00