Radiation dose reduction using a CdZnTe-based computed tomography system: comparison to flat-panel detectors.

abstract：:The determination of the radiation exposure history of the population has become increasingly important in the study of the effects of low-level radiation. The present work was started to try to obtain an in vivo dosimeter that could give an indication of radiation exposure. Dental enamel is the only living tissue whi...

journal_title：Medical physics

authors： Pass B,Aldrich JE

更新日期：1985-05-01 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：:Modern computed tomography (CT) scanners use cone-beam configurations for increasing volume coverage, improving x-ray-tube utilization, and yielding isotropic spatial resolution. Recently, there have been significant developments in theory and algorithms for exact image reconstruction from cone-beam projections. In pa...

journal_title：Medical physics

authors： Zuo N,Xia D,Zou Y,Jiang T,Pan XC

更新日期：2006-10-01 00:00:00

abstract：:This article provides a quantitative evaluation of Varian Medical Systems' beam matching procedure. A one-dimensional y analysis is employed to investigate the level of agreement of matched beams. A customized concept of one-dimensional gamma evaluation was designed. Our algorithm first performs a "local" fit of the r...

journal_title：Medical physics

authors： Hrbacek J,Depuydt T,Nulens A,Swinnen A,Van den Heuvel F

更新日期：2007-07-01 00:00:00

abstract：:Gd2O2S phosphor screens between 250 and 1000 mg/cm2 thick were evaluated for use in megavoltage imaging systems. The phosphor layers were placed on brass plates ranging from 1 to 5 mm thick, each with and without an optical back reflector (white paint). Light output and spatial resolution were measured at 6- and 23-MV...

journal_title：Medical physics

authors： Wowk B,Shalev S

更新日期：1994-08-01 00:00:00

abstract：:Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tis...

journal_title：Medical physics

authors： Pogue BW,Paulsen KD,Samkoe KS,Elliott JT,Hasan T,Strong TV,Draney DR,Feldwisch J

更新日期：2016-06-01 00:00:00

abstract：PURPOSE:Onboard imaging-currently performed primarily by x-ray transmission modalities-is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single pho...

journal_title：Medical physics

authors： Bowsher J,Yan S,Roper J,Giles W,Yin FF

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:To reduce image noise and radiation dose in Digital Breast Tomosynthesis (DBT) reconstructions. METHODS:A retrospective study was performed on clinical data sets acquired at a normal dose with Hologic Selenia Dimensions DBT systems. The Prior Image Constrained Compressed Sensing (PICCS) algorithm was used to r...

journal_title：Medical physics

authors： Garrett J,Tang J,Zhang Y,Ruth C,Jing Z,Chen GH

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Deformable image registration (DIR) is often validated based on a distance-to-agreement (DTA) criterion of automatically propagated anatomical landmarks that were manually identified. Due to human observer variability, however, the performance of the registration method is diluted. The purpose of this study was...

journal_title：Medical physics

authors： Mencarelli A,van Beek S,van Kranen S,Rasch C,van Herk M,Sonke JJ

更新日期：2012-11-01 00:00:00

abstract：PURPOSE:The authors investigated the performance of a recently introduced 160-mm/256-row CT system for low dose quantitative myocardial perfusion (MP) imaging of the whole heart. This platform is equipped with a gantry capable of rotating at 280 ms per full cycle, a second generation of adaptive statistical iterative r...

journal_title：Medical physics

authors： So A,Imai Y,Nett B,Jackson J,Nett L,Hsieh J,Wisenberg G,Teefy P,Yadegari A,Islam A,Lee TY

更新日期：2016-08-01 00:00:00

abstract：:Digital tomosynthesis (DTS) is a fast, low-dose three-dimensional (3D) imaging approach which yields slice images with excellent in-plane resolution, though low plane-to-plane resolution. A stack of DTS slices can be reconstructed from a single limited-angle scan, with typical scan angles ranging from 10 degrees to 40...

journal_title：Medical physics

authors： Godfrey DJ,Ren L,Yan H,Wu Q,Yoo S,Oldham M,Yin FF

更新日期：2007-08-01 00:00:00

abstract：:The Radiological Physics Center (RPC) developed two heterogeneous anthropomorphic quality assurance phantoms for use in verifying the accuracy of radiation delivery: one for intensity-modulated radiation therapy (IMRT) to the pelvis and the other for stereotactic body radiation therapy (SBRT) to the thorax. The purpos...

journal_title：Medical physics

authors： Followill DS,Evans DR,Cherry C,Molineu A,Fisher G,Hanson WF,Ibbott GS

更新日期：2007-06-01 00:00:00

abstract：PURPOSE:There is evidence that computed tomography (CT) and positron emission tomography (PET) imaging metrics are prognostic and predictive in nonsmall cell lung cancer (NSCLC) treatment outcomes. However, few studies have explored the use of standardized uptake value (SUV)-based image features of nodal regions as pre...

journal_title：Medical physics

authors： Li H,Becker N,Raman S,Chan TC,Bissonnette JP

更新日期：2015-08-01 00:00:00

abstract：PURPOSE:In previous work, the authors developed and demonstrated the concept of an image reconstruction procedure aimed to unify gated and dynamic nuclear cardiac imaging, which the authors have termed five-dimensional (5D) SPECT. Gated imaging permits the clinician to evaluate wall motion and, through the use of stres...

journal_title：Medical physics

authors： Niu X,Yang Y,King MA,Wernick MN

更新日期：2010-09-01 00:00:00

abstract：:An automated technique has been developed for the verification of treatment field size and shape in external beam radiation therapy. Portal images from film or digital on-line imaging system are analyzed, and basic parameters are derived to describe the field size and shape from the contour points on the field boundar...

journal_title：Medical physics

authors： Leszczynski KW,Shalev S,Gluhchev G

更新日期：1993-05-01 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:The authors combine the registration of 2D beam's eye view (BEV) images and 3D planning computed tomography (CT) images, with relative, markerless tumor tracking to provide automatic absolute tracking of physician defined volumes such as the gross tumor volume (GTV). METHODS:During treatment of lung SBRT cases...

journal_title：Medical physics

authors： Bryant JH,Rottmann J,Lewis JH,Mishra P,Keall PJ,Berbeco RI

更新日期：2014-12-01 00:00:00

abstract：PURPOSE:Computed tomography (CT) is one of the most used imaging modalities for imaging both symptomatic and asymptomatic patients. However, because of the high demand for lower radiation dose during CT scans, the reconstructed image can suffer from noise and artifacts due to the trade-off between the image quality and...

journal_title：Medical physics

authors： Kim K,El Fakhri G,Li Q

更新日期：2017-10-01 00:00:00

abstract：:Skeletal dosimetry based on microCT images of trabecular bone has recently been introduced to calculate the red bone marrow (RBM) and the bone surface cell (BSC) equivalent doses in human phantoms for external exposure to photons. In order to use the microCT images for skeletal dosimetry, spongiosa voxels in the skele...

journal_title：Medical physics

authors： Kramer R,Khoury HJ,Vieira JW,Robson Brown KA

更新日期：2009-11-01 00:00:00

abstract：:Our purpose in this work is to demonstrate that the efficiency of dose-rate computations in 125I brachytherapy, using multigroup discrete ordinates radiation transport simulations, can be significantly enhanced using broad energy group cross sections without a loss of accuracy. To this end, the DANTSYS multigroup disc...

journal_title：Medical physics

authors： Daskalov GM,Baker RS,Rogers DW,Williamson JF

更新日期：2002-02-01 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

authors： Flannery A,Veber J,Greenfield MA,McIntyre AB,Hamilton DR

更新日期：1980-05-01 00:00:00

abstract：PURPOSE:Body composition is known to be associated with many diseases including diabetes, cancers, and cardiovascular diseases. In this paper, we developed a fully automatic body tissue decomposition procedure to segment three major compartments that are related to body composition analysis - subcutaneous adipose tissu...

journal_title：Medical physics

authors： Fu Y,Ippolito JE,Ludwig DR,Nizamuddin R,Li HH,Yang D

更新日期：2020-11-01 00:00:00

abstract：:One of the methods currently being used to treat choroidal melanoma employs an episcleral plaque containing I-125 radioactive seeds. However, comprehensive dosimetry studies on the plaque are scarce and controversial. For this work, we use film to study the dosimetry outside the lip of the gold shield of the eye plaqu...

journal_title：Medical physics

authors： Wu A,Krasin F

更新日期：1990-09-01 00:00:00

abstract：PURPOSE:Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in co...

journal_title：Medical physics

authors： Andreassen B,Strååt SJ,Holmberg R,Näfstadius P,Brahme A

更新日期：2011-08-01 00:00:00

abstract：PURPOSE:To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted i...

journal_title：Medical physics

authors： Ubeda C,Miranda P,Vano E

更新日期：2015-02-01 00:00:00

abstract：PURPOSE:For cone-beam computed tomography (CBCT) systems, we propose a sphere phantom based method to estimate the full three-dimensional (3D) modulation transfer function (MTF). METHODS:The FDK reconstruction of CBCT system in a local region was modeled by a triple convolution operator. Afterward, we calculated the d...

journal_title：Medical physics

authors： Lee C,Song HD,Baek J

更新日期：2020-07-01 00:00:00

abstract：:A new type of radiographic film, EDR (extended dose range) film, has been recently become available for film dosimetry. It is particularly attractive for composite isodose verification of intensity modulated radiation therapy because of its low sensitivity relative to the more common Kodak XV film. For XV film, the re...

journal_title：Medical physics

authors： Zhu XR,Yoo S,Jursinic PA,Grimm DF,Lopez F,Rownd JJ,Gillin MT

更新日期：2003-05-01 00:00:00

abstract：PURPOSE:To evaluate two deformable image registration (DIR) algorithms for the purpose of contour mapping to support image guided adaptive radiotherapy (IGART) with 4D cone beam CT (4DCBCT). METHODS:Eleven locally advanced non-small cell lung cancer (NSCLC) patients underwent one planning 4D fan- beam CT (4DFBCT) and ...

journal_title：Medical physics

authors： Balik S,Hugo G,Weiss E,Jan N,Roman N,Sleeman W,Fatyga M,Christensen G,Murphy M,Lu J,Keall P,Williamson J

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Efficient and accurate segmentations of 3D end-firing transrectal ultrasound (TRUS) images play an important role in planning of 3D TRUS guided prostate biopsy. However, poor image quality of the input 3D TRUS images, such as strong imaging artifacts and speckles, often makes it a challenging task to extract th...

journal_title：Medical physics

authors： Qiu W,Yuan J,Ukwatta E,Fenster A

更新日期：2015-02-01 00:00:00

abstract：:We have measured the linearity, spatial resolution (MTF), noise (NPS), and signal-to-noise characteristics (DQE) of an electronic portal imaging device (EPID) based on an amorphous silicon flat-panel array. The array has a 128 x 128-pixel matrix and each pixel is 0.75 x 0.75 mm2 in dimension so the array covers an are...

journal_title：Medical physics

authors： Munro P,Bouius DC

更新日期：1998-05-01 00:00:00