Abstract：
:An optimization analysis of digital fluoroscopy has been carried out using (signal/noise)2/dose as a figure of merit. Three signal detection tasks have been considered: (i) small iodine-containing blood vessels; (ii) regions of fat; and (iii) microcalcifications. The effects of x-ray beam filtration and kilovoltage on the figure of merit have been parameterized and the associated x-ray tube power loadings have been defined. Results are presented in a fashion that facilitates the choice of parameters (amount of aluminum filtration, kilovoltage, and x-ray tube power loading) such that an acceptable balance can be achieved between signal detection sensitivity, patient dose, and x-ray tube power loading.
journal_name
Med Physjournal_title
Medical physicsauthors
Zamenhof RGdoi
10.1118/1.595130subject
Has Abstractpub_date
1982-09-01 00:00:00pages
688-94issue
5eissn
0094-2405issn
2473-4209journal_volume
9pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：PURPOSE:To develop a pencil beam dose calculation algorithm for scanned proton beams that improves modeling of scatter events. METHODS:Our pencil beam algorithm (PBA) was developed for calculating dose from monoenergetic, parallel proton beams in homogeneous media. Fermi-Eyges theory was implemented for pencil beam tr...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735624
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Dynamic 18 F-FDG PET allows quantitative estimation of cerebral glucose metabolism both at the regional and local (voxel) level. Although sensitive to noise and highly computationally expensive, nonlinear least-squares (NLS) optimization stands as the reference approach for the estimation of the kinetic model p...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13366
更新日期：2019-03-01 00:00:00
abstract：PURPOSE:Concurrent irradiation of the prostate and pelvic lymph nodes is technically challenging due to treating one moving target and one immobile target. The purposes of this article are to propose a new management strategy and to compare this strategy to the conventional isocenter shift method and the previously pro...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3480505
更新日期：2010-09-01 00:00:00
abstract：:The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comf...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2179751
更新日期：2006-04-01 00:00:00
abstract：PURPOSE:This study aims to measure the surface dose on an anthropomorphic phantom for intensity-modulated radiation therapy (IMRT) plans treated in a 1.5 T magnetic resonance (MR)-Linac. Previous studies have used Monte Carlo programs to simulate surface dose and have recognized high surface dose as a potential limitin...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14185
更新日期：2020-07-01 00:00:00
abstract：PURPOSE:The purpose of this study is to estimate the effect of edema, developed during implant procedure, on tumor cell surviving fraction(SF) and tumor control probability(TCP) in the patients of prostate cancer who underwent 131 Cs permanent seed implants. METHODS:The impact of edema on SF and TCP, was calculated us...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735061
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Transcranial focused ultrasound is an emerging therapeutic modality that can be used to perform noninvasive neurosurgical procedures. The current clinical transcranial phased array operates at 650 kHz, however the development of a higher frequency array would enable more precision, while reducing the risk of st...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4829510
更新日期：2013-12-01 00:00:00
abstract：PURPOSE:To improve image quality and reduce imaging dose in CBCT for radiation therapy applications and to realize near real-time image reconstruction based on use of a fast convergence iterative algorithm and acceleration by multi-GPUs. METHODS:An iterative image reconstruction that sought to minimize a weighted leas...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735747
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Bone strength is the key factor impacting fracture risk. Assessment of bone strength from high-resolution (HR) images have largely relied on linear micro-finite element analysis (μFEA) even though failure always occurs beyond the yield point, which is outside the linear regime. Nonlinear μFEA may therefore be m...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4802085
更新日期：2013-05-01 00:00:00
abstract：:The purpose of this study is to understand the effect of pitch on raw data interpolation in multislice spiral/helical computed tomography (CT) and provide guidelines for scanner design and protocol optimization. Multislice spiral CT is mainly characterized by the three parameters: the number of detector arrays, the de...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598804
更新日期：1999-12-01 00:00:00
abstract：PURPOSE:Prostate cancer ranks as one of the most common malignancies and currently represents the second leading cancer-specific cause of death in men. The current use of single modality transrectal ultrasound (TRUS) for biopsy guidance has a limited sensitivity and specificity for accurately identifying cancerous lesi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4803498
更新日期：2013-06-01 00:00:00
abstract：PURPOSE:Volumetric x-ray microcomputed tomography (CT) can be employed in a variety of quantitative research applications such as image-guided interventions or characterization of medical devices. To ensure the highest geometric fidelity of images for these applications, a phantom and image processing algorithm have be...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4752083
更新日期：2012-10-01 00:00:00
abstract：:Conventional chest radiography is limited by the presence of scattered radiation and the small useful exposure range of radiographic film. A computer-assisted scanning system to minimize these two effects is outlined. The system uses a small beam of radiation swept over the patient's chest in a raster pattern to expos...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595327
更新日期：1983-09-01 00:00:00
abstract：PURPOSE:To characterize the modulation transfer function (MTF) of proton/carbon radiography using Monte Carlo simulations. To assess the spatial resolution of proton/carbon radiographic imaging. METHODS:A phantom was specifically modeled with inserts composed of two materials with three different densities of bone and...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4819816
更新日期：2013-09-01 00:00:00
abstract：PURPOSE:To determine if NSCLC GTV CT textures can be predictive for tumor shrinkage after proton therapy with concurrent chemotherapy. METHODS:Simulation and weekly 4DCTs were obtained from 25 patients with locally advanced NSCLC treated by proton therapy at a 74 Gy dose level with concurrent chemotherapy. In-house de...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735027
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:To build a statistical model to quantitatively correlate the anatomic features of structures and the corresponding dose-volume histogram (DVH) of head and neck (HN) Tomotherapy (Tomo) plans. To study if the model built upon one intensity modulated radiation therapy (IMRT) technique (such as conventional Linac) ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4828788
更新日期：2013-12-01 00:00:00
abstract：:Two side-by-side energy windows, one at the photopeak and one at lower energy, are sometimes employed in quantitative SPECT studies. We measured the count-rate losses at moderately high activities of 131I for two multihead Anger cameras in such a dual-window-acquisition mode by imaging a decaying source composed of tw...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598162
更新日期：1998-01-01 00:00:00
abstract：PURPOSE:Multiple commercial, open-source, and academic software tools exist for objective quantification of lung density in computed tomography (CT) images. The purpose of this study was to evaluate the intersoftware reproducibility of CT lung density measurements. METHODS:Computed tomography images from 50 participan...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14130
更新日期：2020-07-01 00:00:00
abstract：:Single photon emission computed tomography (SPECT) was investigated for imaging on-board radiation therapy machines in order to localize functional and molecular targets. A computer-simulated female NCAT phantom was positioned supine on a flat-top treatment couch. Twenty tumor locations were defined in the upper torso...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3113902
更新日期：2009-05-01 00:00:00
abstract：PURPOSE:Stringent quality assurance is required in MRI breast screening to ensure that different scanners and imaging protocols reach similar diagnostic performance. The authors propose a methodology, based on power spectrum analysis (PSA), to evaluate spatial resolution in clinical images. To demonstrate this approach...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4966704
更新日期：2016-12-01 00:00:00
abstract：:This study presents experimental results about the effective depth of penetration and about the radiofrequency (rf) power absorption in humans as a function of frequency. The frequency range investigated covers 10 up to 220 MHz. For the main part, the results were derived from bench measurements of the quality factor ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595995
更新日期：1987-11-01 00:00:00
abstract：PURPOSE:The purpose of this study was to quantitatively characterize the fundamental aspects of image quality (IQ) associated with different computed tomography (CT) reconstruction algorithms, the resolution, noise texture, noise magnitude per dose, and use those data to devise a methodology to match IQ between differe...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12554
更新日期：2017-11-01 00:00:00
abstract：PURPOSE:Motion is a major confound of image quality in MRI. A method of retrospectively correcting the effects of rotations and translations on the acquired k-space data is presented. METHODS:In two phantom experiments of well-controlled translation and rotation, two MRI-compatible infrared cameras recorded motion dat...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3254189
更新日期：2009-12-01 00:00:00
abstract：:A restricted angular scattering model for electron penetration in dense media is presented. In the model, the Fermi-Eyges transport equation is modified through the addition of an extra term which may be interpreted as representing an apparent force opposing the scattering of electrons into wider angles. The introduct...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596747
更新日期：1991-01-01 00:00:00
abstract：PURPOSE:A number of techniques are available to determine the dosimetric impact of intrafraction motion during intensity modulated radiation therapy (IMRT). Motion-induced dose perturbations can be determined both computationally and experimentally using a number of different dosimetric metrics. However, these measures...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3605633
更新日期：2011-08-01 00:00:00
abstract：:We are evaluating the usefulness of stereomammography in improving breast cancer diagnosis. One area that we are investigating is whether the improved depth perception associated with stereomammography might be significantly enhanced with the use of a virtual 3D cursor. A study was performed to evaluate the accuracy o...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.599008
更新日期：2000-06-01 00:00:00
abstract：:Clinical and biological evidence suggest that the success of GRID therapy in debulking large tumors depends on the high peak-to-valley contrast in the dose distribution. In this study, we show that the peaks and valleys can be significantly blurred out by respiration-induced tumor motion, possibly affecting the clinic...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2977538
更新日期：2008-10-01 00:00:00
abstract：:It is shown that predictions can be made of scatter-to-primary ratios for a variety of mammographic configurations. The different configurations can be produced by changes in source-detector distance; source-phantom distance; air gap; photon energy; phantom composition, thickness, and cross-sectional area. A detailed ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595807
更新日期：1986-11-01 00:00:00
abstract：PURPOSE:To demonstrate the ultra-high resolution capability of a small field-of-view (FOV) solid state x-ray imaging detector based on an EMCCD sensor. METHODS:A micro-solid state x-ray image intensifier (micro-SSXII) was developed to serve as an ultra-high resolution region-of-interest (ROI) imaging detector. It is b...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734816
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:To provide specific experience-based guidance and recommendations for centers wishing to develop, validate, and implement an accurate and efficient process for directly using positron emission tomography-computed tomography (PET-CT) for the radiotherapy planning of head and neck cancer patients. METHODS:A PET-...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4867856
更新日期：2014-04-01 00:00:00
