Sci-Thur PM: YIS - 08: The effect of copper conversion plates on low-Z target image quality.

abstract：PURPOSE:Severe artifacts in kilovoltage-CT simulation images caused by large metallic implants can significantly degrade the conspicuity and apparent CT Hounsfield number of targets and anatomic structures, jeopardize the confidence of anatomical segmentation, and introduce inaccuracies into the radiation therapy treat...

journal_title：Medical physics

authors： Li H,Noel C,Chen H,Harold Li H,Low D,Moore K,Klahr P,Michalski J,Gay HA,Thorstad W,Mutic S

更新日期：2012-12-01 00:00:00

abstract：PURPOSE:Consistency verification between the data from treatment planning system (TPS), record and verification system (R&V), and delivered recorder with visual inspection is time consuming and subject to human error. The purpose of this work is to develop a software tool to automatically perform such verifications. M...

journal_title：Medical physics

authors： Chen G,Li X

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:The purpose of this study was to assess, using an anthropomorphic digital phantom, the accuracy of algorithms in registering precontrast and contrast-enhanced computed tomography (CT) chest images for generation of iodine maps of the pulmonary parenchyma via temporal subtraction. MATERIALS AND METHODS:The XCAT...

journal_title：Medical physics

authors： Grob D,Oostveen L,Rühaak J,Heldmann S,Mohr B,Michielsen K,Dorn S,Prokop M,Kachelrieβ M,Brink M,Sechopoulos I

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:To investigate the effect of energy (kVp) and filters (no filter, half Bowtie, and full Bowtie) on the dose response curves of the Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters (OSLDs) in CBCT dose fields. To measure surface and internal doses received during x-ray volume imager (...

journal_title：Medical physics

authors： Giaddui T,Cui Y,Galvin J,Yu Y,Xiao Y

更新日期：2013-06-01 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：:Intravascular brachytherapy requires that the dose be specified within millimeters of the source. High dose gradients near brachytherapy sources require that the source-detector distance be accurately known for dosimetry purposes. Solid phantoms can be designed to accommodate these stringent requirements. This study r...

journal_title：Medical physics

authors： Buckley LA,Thomadsen BR,DeWerd LA

更新日期：2001-06-01 00:00:00

abstract：PURPOSE:To develop and evaluate the impact on lesion conspicuity of a software-based x-ray scatter correction algorithm for digital breast tomosynthesis (DBT) imaging into which a precomputed library of x-ray scatter maps is incorporated. METHODS:A previously developed model of compressed breast shapes undergoing mamm...

journal_title：Medical physics

authors： Feng SS,D'Orsi CJ,Newell MS,Seidel RL,Patel B,Sechopoulos I

更新日期：2014-03-01 00:00:00

abstract：PURPOSE:This work concerns computed tomography (CT)-based cardiac functional analysis (CFA) with a reduced radiation dose. As CT-CFA requires images over the entire heartbeat, the scans are often performed at 10-20% of the tube current settings that are typically used for coronary CT angiography. A large image noise th...

journal_title：Medical physics

authors： Fung GSK,Ciuffo L,Ashikaga H,Taguchi K

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Temporal subtraction is used to detect the interval change in chest radiographs and aid radiologists in patient diagnosis. This method registers two temporally different images by geometrically warping the lung region, or "lung mask," of a previous radiographic image to align with the current image. The gray le...

journal_title：Medical physics

authors： Armato SG 3rd,Sensakovic WF,Passen SJ,Engelmann R,MacMahon H

更新日期：2009-12-01 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

authors： Yang S,Wang G,Skinner MW,Rubinstein JT,Vannier MW

更新日期：2000-04-01 00:00:00

abstract：PURPOSE:Particle therapy is becoming increasingly available world-wide for precise tumor targeting, its favorable depth dose deposition, and increased biological damage to tumor tissue compared to conventional photon therapy. As demand increases for improved robustness and conformality, next-generation secondary dose c...

journal_title：Medical physics

authors： Kopp B,Fuglsang Jensen M,Mein S,Hoffmann L,Nyström H,Falk M,Haberer T,Abdollahi A,Debus J,Mairani A

更新日期：2020-10-01 00:00:00

abstract：PURPOSE:The advent of three-dimensional breast imaging systems such as digital breast tomosynthesis (DBT) has great promise for improving the detection and diagnosis of breast cancer. With these new technologies comes an essential need for testing methods to assess the resultant image quality. Although randomized clini...

journal_title：Medical physics

authors： Ikejimba LC,Salad J,Graff CG,Ghammraoui B,Cheng WC,Lo JY,Glick SJ

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:Integrating a linac with a magnetic resonance imager (MRI) will revolutionize the accuracy of external beam radiation treatments. Irradiating in the presence of a strong magnetic field, however, will modify the dose distribution. These dose modifications have been investigated previously, mainly using Monte Car...

journal_title：Medical physics

authors： Ghila A,Steciw S,Fallone BG,Rathee S

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:To evaluate a commercial volumetric modulated arc therapy (VMAT), using multiple noncoplanar arcs, for linac-based cranial radiosurgery, as well as evaluate the combined accuracy of the VMAT dose calculations and delivery. METHODS:Twelve patients with cranial lesions of variable size (0.1-29 cc) and two multip...

journal_title：Medical physics

authors： Audet C,Poffenbarger BA,Chang P,Jackson PS,Lundahl RE,Ryu SI,Ray GR

更新日期：2011-11-01 00:00:00

abstract：:A Monte Carlo computer study of the total dose distribution from neutrons and prompt gamma emissions (but excluding the contribution from conversion and Auger electrons) for gadolinium neutron capture therapy of brain tumors has been carried out in order to test the theoretic feasibility of this modality using commerc...

journal_title：Medical physics

authors： Masiakowski JT,Horton JL,Peters LJ

更新日期：1992-09-01 00:00:00

abstract：:A new beam line for radiotherapy and radiosurgery with accelerated helium-ion beams has been set up at the Bevalac. The new treatment room has been equipped with a very precise patient positioner in order to utilize the superior dose localization properties of light-ion beams. The beam spreading and shaping system is ...

journal_title：Medical physics

authors： Ludewigt BA,Chu WT,Phillips MH,Renner TR

更新日期：1991-01-01 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

authors： Marziani M,Taibi A,Di Domenico G,Gambaccini M

更新日期：2009-10-01 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：:The purpose of this work is to investigate algorithms for the delivery of intensity-modulated fields using independent collimators (IC). Two heuristic algorithms are proposed to calculate jaw-setting sequences for arbitrary 2D intensity distributions. The first algorithm is based on searching the whole intensity matri...

journal_title：Medical physics

authors： Dai JR,Hu YM

更新日期：1999-12-01 00:00:00

abstract：:The use of characteristic-line radiation from rare-earth targets bombarded by high-energy (up to 1 MeV) electron beams has been evaluated as an x-ray source for dual energy K-edge subtraction imaging of the human coronary arteries. Two characteristic-line x-ray sources, one using the split K alpha 1 and K alpha 2 line...

journal_title：Medical physics

authors： Manning HL,Shefer RE,Klinkowstein RE,Mistretta CA

更新日期：1991-09-01 00:00:00

abstract：PURPOSE:Bilateral filters have been substantially exploited in numerous magnetic resonance (MR) image restoration applications for decades. Due to the deficiency of theoretical basis on the filter parameter setting, empirical manipulation with fixed values and noise variance-related adjustments has generally been emplo...

journal_title：Medical physics

authors： Chang HH,Chang YN

更新日期：2017-04-01 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：PURPOSE:Accurate calculation of proton stopping power ratio (SPR) relative to water is crucial to proton therapy treatment planning, since SPR affects prediction of beam range. Current standard practice derives SPR using a single CT scan. Recent studies showed that dual-energy CT (DECT) offers advantages to accurately ...

journal_title：Medical physics

authors： Shen C,Li B,Chen L,Yang M,Lou Y,Jia X

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:There are currently several commercially available radiotherapy treatment units without a flattening filter in the beam line. Unflattened photon beams have an energy and lateral fluence distribution that is different from conventional beams and, thus, their attenuation properties differ. As a consequence, for f...

journal_title：Medical physics

authors： Dalaryd M,Knöös T,Ceberg C

更新日期：2014-11-01 00:00:00

abstract：:DICOM format is the de facto standard for communications between therapeutic and diagnostic modalities. A plan generated by a treatment planning system (TPS) is often exported to DICOM format. BEAMnrc/DOSXYZnrc is a widely used Monte Carlo (MC) package for beam and dose simulations in radiotherapy. It has its own defi...

journal_title：Medical physics

authors： Zhan L,Jiang R,Osei EK

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:We report on the development of the open-source cross-platform radiation treatment planning toolkit matRad and its comparison against validated treatment planning systems. The toolkit enables three-dimensional intensity-modulated radiation therapy treatment planning for photons, scanned protons and scanned carb...

journal_title：Medical physics

authors： Wieser HP,Cisternas E,Wahl N,Ulrich S,Stadler A,Mescher H,Müller LR,Klinge T,Gabrys H,Burigo L,Mairani A,Ecker S,Ackermann B,Ellerbrock M,Parodi K,Jäkel O,Bangert M

更新日期：2017-06-01 00:00:00

abstract：PURPOSE:A dosimetric system formed by Gafchromic EBT2 radiochromic film and Epson Expression 10000XL flatbed scanner was commissioned for dosimetry. In this paper, several open questions concerning the commissioning of radiochromic films for dosimetry were addressed: (a) is it possible to employ this dosimetric system ...

journal_title：Medical physics

authors： Mendez I,Hartman V,Hudej R,Strojnik A,Casar B

更新日期：2013-01-01 00:00:00

abstract：PURPOSE:Intraventricular hemorrhage (IVH) is a major cause of brain injury in preterm neonates. Three dimensional ultrasound (US) imaging systems have been developed to visualize 3D anatomical structure of preterm neonatal intracranial ventricular system with IVH and ventricular dilation. To allow quantitative analysis...

journal_title：Medical physics

authors： Chen Y,Qiu W,Kishimoto J,Gao Y,Chan RH,de Ribaupierre S,Fenster A,Chiu B

更新日期：2015-11-01 00:00:00

abstract：PURPOSE:In computed tomography (CT), organ dose, effective dose, and risk index can be estimated from volume-weighted CT dose index (CTDI(vol)) or dose-length product (DLP) using conversion coefficients. Studies have investigated how these coefficients vary across scanner models, scan parameters, and patient size. Howe...

journal_title：Medical physics

authors： Li X,Samei E,Williams CH,Segars WP,Tward DJ,Miller MI,Ratnanather JT,Paulson EK,Frush DP

更新日期：2012-11-01 00:00:00

abstract：:Breast density is a strong predictor of the failure of mammography screening to detect breast cancer and is a strong predictor of the risk of developing breast cancer. The many imaging options that are now available for imaging dense breasts show great promise, but there is still the question of determining which wome...

journal_title：Medical physics

authors： Ng KH,Lau S

更新日期：2015-12-01 00:00:00