Abstract:
PURPOSE:To assess the noise characteristics of the new adaptive statistical iterative reconstruction (ASiR-V) in comparison to ASiR. METHODS:A water phantom was acquired with common clinical scanning parameters, at five different levels of CTDIvol . Images were reconstructed with different kernels (STD, SOFT, and BONE), different IR levels (40%, 60%, and 100%) and different slice thickness (ST) (0.625 and 2.5 mm), both for ASiR-V and ASiR. Noise properties were investigated and noise power spectrum (NPS) was evaluated. RESULTS:ASiR-V significantly reduced noise relative to FBP: noise reduction was in the range 23%-60% for a 0.625 mm ST and 12%-64% for the 2.5 mm ST. Above 2 mGy, noise reduction for ASiR-V had no dependence on dose. Noise reduction for ASIR-V has dependence on ST, being greater for STD and SOFT kernels at 2.5 mm. For the STD kernel ASiR-V has greater noise reduction for both ST, if compared to ASiR. For the SOFT kernel, results varies according to dose and ST, while for BONE kernel ASIR-V shows less noise reduction. NPS for CT Revolution has dose dependent behavior at lower doses. NPS for ASIR-V and ASiR is similar, showing a shift toward lower frequencies as the IR level increases for STD and SOFT kernels. The NPS is different between ASiR-V and ASIR with BONE kernel. NPS for ASiR-V appears to be ST dependent, having a shift toward lower frequencies for 2.5 mm ST. CONCLUSIONS:ASiR-V showed greater noise reduction than ASiR for STD and SOFT kernels, while keeping the same NPS. For the BONE kernel, ASiR-V presents a completely different behavior, with less noise reduction and modified NPS. Noise properties of the ASiR-V are dependent on reconstruction slice thickness. The noise properties of ASiR-V suggest the need for further measurements and efforts to establish new CT protocols to optimize clinical imaging.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
De Marco P,Origgi Ddoi
10.1002/acm2.12253subject
Has Abstractpub_date
2018-03-01 00:00:00pages
275-286issue
2issn
1526-9914journal_volume
19pub_type
杂志文章abstract::This paper investigates the accuracy of the two available calculation algorithms of the Oncentra MasterPlan three-dimensional treatment planning system (TPS)-- the pencil beam method and collapsed-cone convolution--in modeling the Varian enhanced dynamic wedge (EDW). Measurements were carried out for a dual high energ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i2.2867
更新日期:2009-04-22 00:00:00
abstract::The purpose of this study was to assess treatment margins in free-breathing irradiation of pancreatic cancer after bone alignment, and evaluate their impact on conformal radiotherapy. Fifteen patients with adenocarcinoma of the head of the pancreas underwent implantation of single fiducial marker. Intrafraction uncert...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i4.4152
更新日期:2013-07-08 00:00:00
abstract:OBJECTIVES:To compare the effectiveness of two different patient size metrics based on water equivalent diameter (Dw ), the mid-scan water equivalent diameter Dw_c , and the mean (average) water equivalent diameter in the imaged region, Dw_ave , for automatic detection of accidental changes in computed tomography (CT) ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12240
更新日期:2018-01-01 00:00:00
abstract::This study details the generation, verification, and implementation of a treatment planning system (TPS) couch top model for patient support system used in conjunction with a dedicated stereotactic linear accelerator. Couch top model was created within the TPS using CT simulation images of the kVue Calpyso-compatible ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i4.5441
更新日期:2015-07-08 00:00:00
abstract::In this study, we compared the amount of lung tissue irradiated when respiratory gating was imposed during expiration with the amount of lung tissue irradiated when gating was imposed during inspiration. Our hypothesis was that the amount of lung tissue spared increased as inspiration increased. Computed tomography (C...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
doi:10.1120/jacmp.26.146
更新日期:2004-01-01 00:00:00
abstract::We report on initial patient studies to evaluate the performance of a commercial respiratory gating radiotherapy system. The system uses a breathing monitor, consisting of a video camera and passive infrared reflective markers placed on the patient's thorax, to synchronize radiation from a linear accelerator with the ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v2i4.2596
更新日期:2001-10-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The purpose of this study of pancreatic cancer patients treated with respiratory-guided stereotactic body radiotherapy (SBRT) on a standard linac was to investigate (a) the intrafractional relationship change (IRC) between a breathing signal and the tumor position, (b) the impact of IRC on the de...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12841
更新日期:2020-03-01 00:00:00
abstract::The longitudinal coverage of a LINAC-mounted CBCT scan is limited to the corresponding dimensional limits of its flat panel detector, which is often shorter than the length of the treatment field. These limits become apparent when fields are designed to encompass wide regions, as when providing nodal coverage. Therefo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i4.3796
更新日期:2012-07-05 00:00:00
abstract::The aim of this study was to report a single-institution experience and commissioning data for Elekta VersaHD linear accelerators (LINACs) for photon beams in the Eclipse treatment planning system (TPS). Two VersaHD LINACs equipped with 160-leaf collimators were commissioned. For each energy, the percent-depth-dose (P...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
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更新日期:2019-10-01 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12287
更新日期:2018-05-01 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6148
更新日期:2016-09-08 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6237
更新日期:2016-09-08 00:00:00
abstract::A method to evaluate the electron beam energy constancy by employing the computed radiography (CR) system has been developed. In this method, a right triangular plastic wedge is used to produce a curve of the CR storage phosphor plate signal versus the wedge thickness. The curve, which resembles the percentage depth i...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i4.2911
更新日期:2009-10-15 00:00:00
abstract::The assessment of the coincidence of imaging and radiation isocenters is an important task of regular quality assurance of medical linear accelerators (linacs) as recommended in national and international quality assurance guidelines. A previously reported investigation of the accuracy of the Elekta XVI software to lo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12861
更新日期:2020-05-01 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i3.5900
更新日期:2016-05-08 00:00:00
abstract:INTRODUCTION:Aim of this study is to dosimetrically characterize a new inorganic scintillator designed for magnetic resonance-guided radiotherapy (MRgRT) in the presence of 0.35 tesla magnetic field (B). METHODS:The detector was characterized in terms of signal to noise ratio (SNR), reproducibility, dose linearity, an...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13012
更新日期:2020-09-01 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v5i4.1964
更新日期:2004-10-01 00:00:00
abstract::Radiochromic film has become an important tool to verify dose distributions in highly conformal radiation therapy such as IMRT. Recently, a new generation of these films, EBT3, has become available. EBT3 has the same composition and thickness of the sensitive layer of the previous EBT2 films, but its symmetric layer c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i2.4111
更新日期:2013-03-04 00:00:00
abstract::The necessity to build or adapt radiotherapy rooms in reduced areas leads to the search for unconventional solutions for shielding projects. In most cases, adding metals to the primary barriers is the best alternative to shield rooms properly. However, when photons with energies equal or higher than 10 MV interact wit...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i6.5035
更新日期:2014-11-08 00:00:00
abstract::The main purposes of this study are to: 1) evaluate the accuracy of XiO treatment planning system (TPS) for different dose calculation grid size based on head phan-tom measurements in uniform scanning proton therapy (USPT); and 2) compare the dosimetric results for various dose calculation grid sizes based on real com...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
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更新日期:2015-09-08 00:00:00
abstract::The purpose of this study is to describe the comprehensive commissioning process and initial clinical experience of the Mevion S250 proton therapy system, a gantry-mounted, single-room proton therapy platform clinically implemented in the S. Lee Kling Proton Therapy Center at Barnes-Jewish Hospital in St. Louis, MO, U...
journal_title:Journal of applied clinical medical physics
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更新日期:2016-03-08 00:00:00
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journal_title:Journal of applied clinical medical physics
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更新日期:2020-10-01 00:00:00
abstract::The purpose of this study was to determine the reproducibility of patient-specific, intensity-modulated radiation therapy (IMRT) quality assurance (QA) results in a clinical setting. Six clinical patient plans were delivered to a variety of devices and analyses, including 1) radiographic film; 2) ion chamber; 3) 2D di...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
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更新日期:2014-05-08 00:00:00
abstract::Beam quality correction kQQo (r), which reflects the absorbed energy dependence of the detector, is calculated for solid state detector materials diamond, LiF, Li2B4O7 and Al2O3 for the 137Cs RTR brachytherapy source using the Monte Carlo-based EGSnrc code system. The study also includes calculation of detector-specif...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
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更新日期:2014-01-06 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
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更新日期:2018-11-01 00:00:00
abstract::Increasingly, the advent of multislice CT scanners, volume CT scanners, and total body spiral acquisition modes has led to the use of Multi Planar Reconstruction and 3D datasets. In considering 3D resolution properties of a CT system it is important to note that both the in-plane (x,y) and z-axis (slice thickness) inf...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6294
更新日期:2016-09-08 00:00:00
abstract:PURPOSE:Adaptive radiotherapy (ART) has potential to reduce toxicity and facilitate safe dose escalation. Dose calculations with the planning CT deformed to cone beam CT (CBCT) have shown promise for estimating the "dose of the day". The purpose of this study is to investigate the "dose of the day" calculation accuracy...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12793
更新日期:2020-01-01 00:00:00
abstract::The use of a radioactive check device containing Strontium 90 was investigated to carry out the redundancy checks of Farmer-type ionization chambers. It was not possible to meet the recommended tolerance limits of the redundancy checks without taking into account the angular response of the ionization chambers. The io...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v1i4.2636
更新日期:2000-10-01 00:00:00
abstract:PURPOSE:The aim of the current study was to evaluate the backscatter dose and energy spectrum from the Lipiodol with flattening filter (FF) and flattening filter-free (FFF) beams. Moreover, the backscatter range, that was defined as the backscatter distance (BD) are revealed. METHODS:6 MVX FF and FFF beams were delive...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12560
更新日期:2019-06-01 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12959
更新日期:2020-09-01 00:00:00