Abstract：
:Multislice helical computed tomography (CT) is a promising noninvasive technique for coronary artery imaging. Various factors can cause inconsistencies in cardiac CT data, which can result in degraded image quality. These inconsistencies may be the result of the patient physiology (e.g., heart rate variations), the nature of the data (e.g., cone-angle), or the reconstruction algorithm itself. An algorithm which provides the best temporal resolution for each slice, for example, often provides suboptimal image quality for the entire volume since the cardiac temporal resolution (TRc) changes from slice to slice. Such variations in TRc can generate strong banding artifacts in multiplanar reconstruction images or three-dimensional images. Discontinuous heart walls and coronary arteries may compromise the accuracy of the diagnosis. A beta-blocker is often used to reduce and stabilize patients' heart rate but cannot eliminate the variation. In order to obtain robust and optimal image quality, a software solution that increases the temporal resolution and decreases the effect of heart rate is highly desirable. This paper proposes an ECG-correlated direct cone-beam reconstruction algorithm (TCOT-EGR) with cardiac banding artifact correction (CBC) and disconnected projections redundancy compensation technique (DIRECT). First the theory and analytical model of the cardiac temporal resolution is outlined. Next, the performance of the proposed algorithms is evaluated by using computer simulations as well as patient data. It will be shown that the proposed algorithms enhance the robustness of the image quality against inconsistencies by guaranteeing smooth transition of heart cycles used in reconstruction.
journal_name
Med Physjournal_title
Medical physicsauthors
Taguchi K,Chiang BS,Hein IAdoi
10.1118/1.2163247subject
Has Abstractpub_date
2006-02-01 00:00:00pages
521-39issue
2eissn
0094-2405issn
2473-4209journal_volume
33pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：PURPOSE:To develop an automated treatment planning strategy for external beam intensity-modulated radiation therapy (IMRT), including a deep learning-based three-dimensional (3D) dose prediction and a dose distribution-based plan generation algorithm. METHODS AND MATERIALS:A residual neural network-based deep learning...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13271
更新日期：2019-01-01 00:00:00
abstract：PURPOSE:To study if malfunction of a receiver can be detected robustly using the simple ACR SNR measurement approach on a 32-channel head coil. METHODS:Standard ACR T1W images (11slice) were acquired with a commercial 32 channel head coil on a 3T Philips Achieva MR scanner following the ACR recommended setup. Raw data...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4736227
更新日期：2012-06-01 00:00:00
abstract：:A detailed derivation is presented of the formulas required to determine Ngas and Dmed in the AAPM TG-21 dosimetry protocol. This protocol specifies how to determine the absorbed dose in an electron or photon beam when using exposure or absorbed dose calibrated ion chambers. It is shown that the expression given in TG...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596292
更新日期：1988-01-01 00:00:00
abstract：:A commercially available open MRI unit is under routine use for radiation therapy simulation. The effects of a gradient distortion correction (GDC) program used to post process the images were assessed by comparison with the known geometry of a phantom. The GDC reduced the magnitude of the distortions at the periphery...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1513991
更新日期：2002-11-01 00:00:00
abstract：:A high sensitivity (HS) model of radiochromic film is receiving increasing use. The film's linear sensitometric response in the range of 0.5-40 Gy would make this film an ideal candidate for complex dosimetry applications that require tissue equivalence. This study investigates the potential use for clinical dosimetry...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1883565
更新日期：2005-04-01 00:00:00
abstract：PURPOSE:Recent guidance by The Joint Commission and CRCPD recommendations require establishing CT reference dose levels (RDLs) for clinical protocols and recording CT dose metrics in the patient's medical record. This presentation addresses which dose values in the CT report should be recorded for the purposes of monit...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734773
更新日期：2012-06-01 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
pub_type： 杂志文章
doi：10.1118/1.595000
更新日期：1981-07-01 00:00:00
abstract：BACKGROUND:X-ray dark-field radiography could enhance mammography by providing more information on imaged tissue and microcalcifications. The dark field signal is a measure of small angle scattering and can thus provide additional information on the imaged materials. This information can be useful for material distinct...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14043
更新日期：2020-04-01 00:00:00
abstract：PURPOSE:Transurethral MR-HIFU is a minimally invasive image-guided treatment for localized prostate cancer that enables precise targeting of tissue within the gland. The treatment is performed within a clinical MRI to obtain real-time MR thermometry used as an active feedback to control the spatial heating pattern in t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4897382
更新日期：2014-11-01 00:00:00
abstract：PURPOSE:To model X-ray coherent scatter diffraction patterns in GEANT4 for simulating experiments involving material detection through diffraction pattern measurement. Although coherent scatter cross-sections are modeled accurately in GEANT4, diffraction patterns for crystalline materials are not yet included. Here we ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734794
更新日期：2012-06-01 00:00:00
abstract：:Neutron cross sections for nonelastic and elastic reactions on a range of elements have been evaluated for incident energies up to 150 MeV. These cross sections agree well with experimental cross section data for charged-particle production as well as neutron and photon production. Therefore they can be used to determ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598601
更新日期：1999-06-01 00:00:00
abstract：PURPOSE:Polymer-based gel dosimeter (MAGIC type) is a preferable phantom material for PET range verification of proton beam therapy. However, improvement in elemental tissue equivalency (specifically O/C ratio) is very desirable to ensure realistic time-activity measurements. METHODS:Glucose and urea was added to the ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3260844
更新日期：2010-01-01 00:00:00
abstract：PURPOSE:In CT-guided liver tumor ablation interventions, registration of a preoperative contrast-enhanced CT image to the intraoperative CT image is hypothesized to improve guidance. This is a highly challenging registration task due to differences in patient poses and large deformations, and therefore high registratio...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12332
更新日期：2017-07-01 00:00:00
abstract：:Delivery verification is the process in which the energy fluence delivered during a treatment is verified. This verified energy fluence can be used in conjunction with an image in the treatment position to reconstruct the full three-dimensional dose deposited. A method for delivery verification that utilizes a measure...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1352579
更新日期：2001-04-01 00:00:00
abstract：PURPOSE:Real-time adaptive planning and treatment has been infeasible due in part to its high computational complexity. There have been many recent efforts to utilize graphics processing units (GPUs) to accelerate the computational performance and dose accuracy in radiation therapy. Data structure and memory access pat...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4895822
更新日期：2014-10-01 00:00:00
abstract：:Lag in fluoroscopic systems introduces a frame-averaging effect that reduces measurements of image noise and incorrectly inflates measurements of the detective quantum efficiency (DQE). A correction can be implemented based on measurements of the temporal modulation transfer function (MTF). We introduce a method of me...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2919724
更新日期：2008-06-01 00:00:00
abstract：PURPOSE:To compare optimization characteristics, plan quality, and treatment delivery efficiency between total marrow irradiation (TMI) plans using the new TomoTherapy graphic processing unit (GPU) based dose engine and CPU/cluster based dose engine. METHODS:Five TMI plans created on an anthropomorphic phantom were op...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4810936
更新日期：2013-07-01 00:00:00
abstract：PURPOSE:High-intensity focused ultrasound (HIFU) has been investigated for ablative therapy and drug enhancement for gene therapy and chemotherapy. The aim of this work is to explore the feasibility of pulsed focused ultrasound (pFUS) for cancer therapy using an in vivo animal model. METHODS:A clinical HIFU system (In...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4901352
更新日期：2014-12-01 00:00:00
abstract：:We propose a new starting point for comparing planar dose distributions using a Jacobian-based measure. The measure is normalization independent, i.e., is sensitive to dose patterns while not being biased by global dose scaling. The measure is free of tunable parameters and is bounded between zero and one. We also pro...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2982136
更新日期：2008-11-01 00:00:00
abstract：:Segmentation of the lungs within magnetic resonance (MR) scans is a necessary step in the computer-based analysis of thoracic MR images. This process is often confounded by image acquisition artifacts and disease-induced morphological deformation. We have developed an automated method for lung segmentation that is ins...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2214165
更新日期：2006-09-01 00:00:00
abstract：PURPOSE:For the purpose of size-specific dose estimation, information regarding patient attenuation is required. The purpose of this work is to describe a method for measuring patient attenuation and expressing the results in terms of a water cylinder, with cross sectional area A(w), which would absorb the same average...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4754303
更新日期：2012-11-01 00:00:00
abstract：PURPOSE:Magnetic resonance imaging (MRI)-guided percutaneous cryotherapy of abdominal lesions, an established procedure, uses MRI to guide and monitor the cryoablation of lesions. Methods to precisely guide cryotherapy probes with a minimum amount of trial-and-error are yet to be established. To aid physicians in attai...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14116
更新日期：2020-06-01 00:00:00
abstract：PURPOSE:To investigate the geometry dependence of the detector response function (DRF) of three commonly used scanning ionization chambers and its impact on a convolution-based method to address the volume averaging effect (VAE). METHODS:A convolution-based approach has been proposed recently to address the ionization...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4944783
更新日期：2016-05-01 00:00:00
abstract：:Using high-energy photon and electron beams, the response of two solid water parallel-plate chambers is evaluated against a PTW (Physicallsch-Technische Werkstatten) Farmer-type chamber. These two chambers are (1) a Memorial "Holt" chamber which was further modified by this author to take advantage of electrically con...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597074
更新日期：1993-03-01 00:00:00
abstract：PURPOSE:The authors had previously published measurements of the detectability of disk-shaped contrast objects in images obtained from a C-arm CT system. A simple approach based on Rose's criterion was used to scale the date, assuming the threshold for the smallest diameter detected should be inversely proportional to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3397465
更新日期：2010-05-01 00:00:00
abstract：PURPOSE:To evaluate the availability and performance of pencil beam algorithm for fast neutrons radiotherapy dose calculations and to achieve improvements in universality, speed and inhomogeneities corrections. METHODS:Pencil beam (PB) method uses integration of dose kernel cross field size to estimate dose distributi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735630
更新日期：2012-06-01 00:00:00
abstract：:Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2042248
更新日期：2005-10-01 00:00:00
abstract：PURPOSE:Monte Carlo (MC) simulation can be used for accurate electron beam treatment planning and modeling. Measurement of large electron fields, with the applicator removed and secondary collimator wide open, has been shown to provide accurate simulation parameters, including asymmetry in the measured dose, for the fu...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3592640
更新日期：2011-06-01 00:00:00
abstract：:The propagation of noise in digitized images arrived at by algebraic manipulation of two images has been investigated. The algebraic manipulations investigated were logarithmic subtraction, linear subtraction, and division of the two images. The two images were identical except for the presence of a contrast-adding co...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595289
更新日期：1983-01-01 00:00:00
abstract：:Results of an 18-alternative forced-choice experiment have shown that observers were capable of detecting a signal with a contrast of 1 in terms of 10-bit data which were displayed on a CRT monitor with an 8-bit video generator and a window width setting of 1024. We investigated the conditions under which 10-bit signa...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595919
更新日期：1986-05-01 00:00:00
