Cascaded systems analysis of anatomic noise in digital mammography and dual-energy digital mammography.

abstract：:Positron range impairs resolution in PET imaging, especially for high-energy emitters and for small-animal PET. De-blurring in image reconstruction is possible if the blurring distribution is known. Furthermore, the percentage of annihilation events within a given distance from the point of positron emission is releva...

journal_title：Physics in medicine and biology

authors： Jødal L,Le Loirec C,Champion C

更新日期：2012-06-21 00:00:00

abstract：:A technique is described by which the regional distribution of bone mineral can be determined in bone samples from small animals. The technique employs an Anger camera interfaced to a medical computer. High resolution (less than 1 mm) imaging is possible by producing magnified images of the bone samples. Regional dens...

journal_title：Physics in medicine and biology

authors： LeBlanc A,Evans H,Jhingran S,Johnson P

更新日期：1984-01-01 00:00:00

abstract：:Cylindrical ionization chambers with varying radii have been used to determine the displacement effect at distances between 10 mm and 40 mm from 60Co and 192Ir brachytherapy sources. Agreement with published values of the displacement factor for external 60Co beams is obtained. The shift between the centre of the ioni...

journal_title：Physics in medicine and biology

authors： Tölli H,Johansson KA

更新日期：1993-10-01 00:00:00

abstract：:With high-dose administration of (90)Y labeled antibodies, it is possible to image (90)Y without an admixture of (111)In. We have earlier shown that it is possible to perform quantitative (90)Y bremsstrahlung SPECT for dosimetry purposes with reasonable accuracy. However, whole-body (WB) activity quantification with t...

journal_title：Physics in medicine and biology

authors： Minarik D,Ljungberg M,Segars P,Gleisner KS

更新日期：2009-10-07 00:00:00

abstract：:Component-based normalization is a method used to compensate for the sensitivity of each of the lines of response acquired in positron emission tomography. This method consists of modelling the sensitivity of each line of response as a product of multiple factors, which can be classified as time-invariant, time-varian...

journal_title：Physics in medicine and biology

authors： Belzunce MA,Reader AJ

更新日期：2016-05-07 00:00:00

abstract：:Contrast enhanced ultrasound (CEUS) and dynamic contrast enhanced ultrasound (DCE-US) can be used to provide information about the vasculature aiding diagnosis and monitoring of a number of pathologies including cancer. In the development of a CEUS imaging system, there are many choices to be made, such as whether to ...

journal_title：Physics in medicine and biology

authors： Moghimirad E,Bamber J,Harris E

更新日期：2019-04-23 00:00:00

abstract：:Tserng and Kalhan have raised the question of the appropriate equation to use for the measurement of turnover rate in a stable-isotope study. In a comparison of glucose turnover measured with 2H-glucose and with 13C-glucose they used five apparently different equations and obtained conflicting answers. There is, howev...

journal_title：Physics in medicine and biology

authors： Wootton R,Ford GC,Cheng KN,Halliday D

更新日期：1985-10-01 00:00:00

abstract：:A method of computing theoretical X-ray spectra in the range 30-150 kV is presented. The theoretical spectra are compared with constant potential, high resolution spectra from a tungsten target measured with a Ge(Li) detector, for a range of target angles, tube voltage and filtrations. Above 100 kV the spectra were al...

journal_title：Physics in medicine and biology

authors： Birch R,Marshall M

更新日期：1979-05-01 00:00:00

abstract：:A method to measure the detector-to-object distance from the images obtained with stationary high-spatial-resolution gamma-ray cameras for in vivo studies has been developed. It exploits the shift of the imaged object in the image plane, obtained at a certain tilt of the parallel-hole collimator. A linear dependence o...

journal_title：Physics in medicine and biology

authors： Uzunov N,Bello M,Boccaccio P,Moschini G,Bollini D,de Notaristefani F

更新日期：2006-05-07 00:00:00

abstract：:Radiomic features achieve promising results in cancer diagnosis, treatment response prediction, and survival prediction. Our goal is to compare the handcrafted (explicitly designed) and deep learning (DL)-based radiomic features extracted from pre-treatment diffusion-weighted magnetic resonance images (DWIs) for predi...

journal_title：Physics in medicine and biology

authors： Fu J,Zhong X,Li N,Van Dams R,Lewis J,Sung K,Raldow AC,Jin J,Qi XS

更新日期：2020-04-02 00:00:00

abstract：:In this note a technique is described for direct aperture optimization of components deliverable by a variable aperture collimator (VAC) for intensity-modulated radiation therapy. The first key result found was that, provided a large number of VAC components were selected for optimization, the resulting fluence profil...

journal_title：Physics in medicine and biology

authors： Webb S

更新日期：2004-03-07 00:00:00

abstract：:As the use of radiofrequency (RF) electromagnetic (EM) fields has increased along with increased use of wireless communication, the possible related health risks have also been widely discussed. One safety aspect is the interaction of medical implants and RF devices like mobile phones. In the literature, effects on ac...

journal_title：Physics in medicine and biology

authors： Virtanen H,Keshvari J,Lappalainen R

更新日期：2007-03-07 00:00:00

abstract：:An extensive study on specific absorption rate (SAR) covering 720 simulations and 15 voxel models (18-105 kg) has been performed by applying the parallel finite-difference time-domain method. High-resolution whole-body models have been irradiated with plane waves from 300 MHz to 5 GHz by applying various incoming dire...

journal_title：Physics in medicine and biology

authors： Uusitupa T,Laakso I,Ilvonen S,Nikoskinen K

更新日期：2010-02-21 00:00:00

abstract：:With the addition of variable bed speed capabilities, continuous bed motion (CBM) becomes an acquisition generalization for axial sensitivity modeling and therefore a flexible tool in axial local image quality adjustment. In this paper, we describe the principles behind CBM mode planning and its influence on image rec...

journal_title：Physics in medicine and biology

authors： Panin VY,Smith AM,Hu J,Kehren F,Casey ME

更新日期：2014-10-21 00:00:00

abstract：:Compton scatter poses a significant threat to volumetric x-ray computed tomography, bringing cupping and streak artefacts thus impacting qualitative and quantitative imaging procedures. To perform appropriate scatter compensation, it is necessary to estimate the magnitude and spatial distribution of x-ray scatter. The...

journal_title：Physics in medicine and biology

authors： Akbarzadeh A,Ay MR,Ghadiri H,Sarkar S,Zaidi H

更新日期：2010-04-21 00:00:00

abstract：:The treatment of lung cancer with radiation therapy is hindered by respiratory motion. Real-time adjustments to compensate for this motion are hampered by mechanical system latencies and imaging-rate restrictions. To better understand tumour motion behaviour for adaptive image-guided radiation therapy of lung cancer, ...

journal_title：Physics in medicine and biology

authors： Pepin EW,Wu H,Sandison GA,Langer M,Shirato H

更新日期：2010-06-21 00:00:00

abstract：:Effects of different scatter compensation methods incorporated in fully 3D iterative reconstruction are investigated. The methods are: (i) the inclusion of an 'ideal scatter estimate' (ISE); (ii) like (i) but with a noiseless scatter estimate (ISE-NF); (iii) incorporation of scatter in the point spread function during...

journal_title：Physics in medicine and biology

authors： Beekman FJ,Kamphuis C,Frey EC

更新日期：1997-08-01 00:00:00

abstract：:The sulphuric acid used for the preparation of the Fricke dosimeter solution may contain trace impurities that can affect the yield of ferric ions. Two methods, pre-irradiation or oxidation with hydrogen peroxide, have been proposed to reduce the influence of these impurities. Fricke users sometimes omit this treatmen...

journal_title：Physics in medicine and biology

authors： Palm A,Mattsson O

更新日期：2000-09-01 00:00:00

abstract：:In elastography we have previously developed a tracking and correction method that estimates the axial and lateral strain components along and perpendicular to the compressor/scanning axis following an externally applied compression. However, the resulting motion is a three-dimensional problem. Therefore, in order to ...

journal_title：Physics in medicine and biology

authors： Konofagou EE,Ophir J

更新日期：2000-06-01 00:00:00

abstract：:A hybrid proportional-integral-in-time and cost-minimizing-in-space feedback control system for electromagnetic, deep regional hyperthermia is proposed. The unique features of this controller are that (1) it uses temperature, not specific absorption rate, as the criterion for selecting the relative phases and amplitud...

journal_title：Physics in medicine and biology

authors： Kowalski ME,Jin JM

更新日期：2003-03-07 00:00:00

abstract：:A reader study was conducted to tune the parameters of an observer model used to predict the detectability index (dʹ ) of test objects as a task-based quality control (QC) metric for digital mammography. A simple test phantom was imaged to measure the model parameters, namely, noise power spectrum,modulation transfer ...

journal_title：Physics in medicine and biology

authors： Bloomquist AK,Mainprize JG,Mawdsley GE,Yaffe MJ

更新日期：2014-11-07 00:00:00

abstract：:The purpose of this study is to develop a new global mammographic image feature analysis based computer-aided detection (CAD) scheme and evaluate its performance in detecting positive screening mammography examinations. A dataset that includes images acquired from 1896 full-field digital mammography (FFDM) screening e...

journal_title：Physics in medicine and biology

authors： Tan M,Qian W,Pu J,Liu H,Zheng B

更新日期：2015-06-07 00:00:00

abstract：:Positron emission tomography (PET) iterative 3D reconstruction is a very computational demanding task. One of the main issues of the iterative reconstruction concerns the management of the system response matrix (SRM). The SRM models the relationship between the projection and the voxel space and its memory footprint ...

journal_title：Physics in medicine and biology

authors： Camarlinghi N,Sportelli G,Guerra AD,Belcari N

更新日期：2018-09-28 00:00:00

abstract：:A method has been developed which, by using the geometric information from treatment sample cases, selects from a given data set an initial treatment plan as a step for treatment plan optimization. The method uses an artificial neural network (ANN) classification technique to select a best matching plan from the 'opti...

journal_title：Physics in medicine and biology

authors： Hosseini-Ashrafi ME,Bagherebadian H,Yahaqi E

更新日期：1999-06-01 00:00:00

abstract：:The elastic and hyperelastic properties of biological soft tissues have been of interest to the medical community. There are several biomedical applications where parameters characterizing such properties are critical for a reliable clinical outcome. These applications include surgery planning, needle biopsy and brach...

journal_title：Physics in medicine and biology

authors： O'Hagan JJ,Samani A

更新日期：2009-04-21 00:00:00

abstract：:Currently, energy spectra of laser accelerated proton beams are far from being monoenergetic. For their application in radiation therapy, energy selection systems using magnetic fields have been proposed to single out particles with the desired energy. These systems allow the choice of protons between a lowest and a h...

journal_title：Physics in medicine and biology

authors： Schell S,Wilkens JJ

更新日期：2009-10-07 00:00:00

abstract：:State of the art point-spread function (PSF) corrections implemented in positron emission tomography/computed tomography (PET/CT) reconstruction improved image quality and diagnostic performance but caused an increase in the standardized uptake value (SUV) compared to a conventional OSEM reconstruction system. The EAN...

journal_title：Physics in medicine and biology

authors： Ferretti A,Chondrogiannis S,Rampin L,Bellan E,Marzola MC,Grassetto G,Gusella S,Maffione AM,Gava M,Rubello D

更新日期：2018-11-26 00:00:00

abstract：:Ion chamber dosimetry requires a high degree of precision, at all steps within the dosimetric process, in order to ensure accurate dose measurements. This work presents a novel technique for ion chamber volume determination and quality assurance, using micro-computed tomography (micro-CT). Four nominally identical Exr...

journal_title：Physics in medicine and biology

authors： McNiven AL,Umoh J,Kron T,Holdsworth DW,Battista JJ

更新日期：2008-09-21 00:00:00

abstract：:The treatment planning process for patients with head and neck (H&N) cancer is regarded as one of the most complicated due to large target volume, multiple prescription dose levels, and many radiation-sensitive critical structures near the target. Treatment planning for this site requires a high level of human experti...

journal_title：Physics in medicine and biology

authors： Nguyen D,Jia X,Sher D,Lin MH,Iqbal Z,Liu H,Jiang S

更新日期：2019-03-18 00:00:00

abstract：:Monte Carlo simulation techniques are applied to track the annihilation photons from positron decay, and store the photon histories. Reasonably realistic models of the isotope distribution in the brain and heart during typical PET studies, as well as the traditional phantoms used for measuring PET scanner performance ...

journal_title：Physics in medicine and biology

authors： Thompson CJ,Moreno-Cantu J,Picard Y

更新日期：1992-03-01 00:00:00