The spatial resolution in dosimetry with normoxic polymer-gels investigated with the dose modulation transfer approach.

abstract：PURPOSE:Motion compensated positron emission tomography (PET) imaging requires detecting and monitoring of patient body motion. We developed a semiautomatic list-mode method to track the three-dimensional (3D) motion of fiducial positron-emitting markers during PET imaging. METHODS:A previously developed motion tracki...

journal_title：Medical physics

authors： Chamberland MJP,deKemp RA,Xu T

更新日期：2020-08-01 00:00:00

abstract：PURPOSE:High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly (192)Ir with an air KERMA strength range between 20,000 and 40,000 U, where 1 U = 1 μGy m(2)/h in a...

journal_title：Medical physics

authors： Espinoza A,Beeksma B,Petasecca M,Fuduli I,Porumb C,Cutajar D,Corde S,Jackson M,Lerch ML,Rosenfeld AB

更新日期：2013-11-01 00:00:00

abstract：PURPOSE:In radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, the information on electron density must be derived from the MRI scan by creating a so-called pseudo computed tomography (pCT). This is a nontrivial task, since the voxel-intensities in an MRI scan are not uniquely related to e...

journal_title：Medical physics

authors： Andreasen D,Van Leemput K,Hansen RH,Andersen JA,Edmund JM

更新日期：2015-04-01 00:00:00

abstract：:An adaptive linear element (Adaline) was developed to estimate the two-dimensional scatter exposure distribution in digital portable chest radiographs (DPCXR). DPCXRs and quantitative scatter exposure measurements at 64 locations throughout the chest were acquired for ten radiographically normal patients. The Adaline ...

journal_title：Medical physics

authors： Lo JY,Floyd CE Jr,Baker JA,Ravin CE

更新日期：1993-07-01 00:00:00

abstract：:The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/ chestwall patients treated wit...

journal_title：Medical physics

authors： Das SK,Baydush AH,Zhou S,Miften M,Yu X,Craciunescu O,Oldham M,Light K,Wong T,Blazing M,Borges-Neto S,Dewhirst MW,Marks LB

更新日期：2005-01-01 00:00:00

abstract：PURPOSE:To develop a hypothesis-generating framework for automatic extraction of dose-outcome relationships from an in-house, analytic oncology database. METHODS:Dose-volume histograms (DVH) and clinical outcomes have been routinely stored to the authors' database for 684 head and neck cancer patients treated from 200...

journal_title：Medical physics

authors： Robertson SP,Quon H,Kiess AP,Moore JA,Yang W,Cheng Z,Afonso S,Allen M,Richardson M,Choflet A,Sharabi A,McNutt TR

更新日期：2015-07-01 00:00:00

abstract：PURPOSE:Intensity-modulated proton therapy (IMPT) is known to be sensitive to patient setup and range uncertainty issues. Multiple robust optimization methods have been developed to mitigate the impact of these uncertainties. Here, we propose a new robust optimization method, which provides an alternative way of robust...

journal_title：Medical physics

authors： Shan J,Sio TT,Liu C,Schild SE,Bues M,Liu W

更新日期：2019-01-01 00:00:00

abstract：:The contribution of a commercially available diode matrix (MapCHECK, provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo (VMC++) algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation ...

journal_title：Medical physics

authors： Borca VC,Pasquino M,Ozzello F,Tofani S

更新日期：2009-04-01 00:00:00

abstract：PURPOSE:In recent years, laser-based acceleration of charged particles has rapidly progressed and medical applications, e.g., in radiotherapy, might become feasible in the coming decade. Requirements are monoenergetic particle beams with long-term stable and reproducible properties as well as sufficient particle intens...

journal_title：Medical physics

authors： Beyreuther E,Enghardt W,Kaluza M,Karsch L,Laschinsky L,Lessmann E,Nicolai M,Pawelke J,Richter C,Sauerbrey R,Schlenvoigt HP,Baumann M

更新日期：2010-04-01 00:00:00

abstract：:A proton beam is extracted from the 200-MeV linear accelerator at the Fermi National Accelerator Laboratory to investigate the efficacy of proton radiography in medical diagnosis. Fluence rates from 2 X 10(3) to 2 X 10(5) protons/cm2s over a 28-cm diameter field are obtained with a full width at half-maximum beam-ener...

journal_title：Medical physics

authors： Curry J,Steward VW

更新日期：1978-05-01 00:00:00

abstract：PURPOSE:Accurate, patient-specific radiation dosimetry for CT scanning is critical to optimize radiation doses and balance dose against image quality. While Monte Carlo (MC) simulation is often used to estimate doses from CT, comparison of estimates to experimentally measured values is lacking for advanced CT scanners ...

journal_title：Medical physics

authors： Prinsen P,Trattner S,Wiegert J,Gerland EL,Shefer E,Morton T,Thompson CM,Cheng B,Halliburton SS,Einstein AJ

更新日期：2019-11-01 00:00:00

abstract：:A computer dose model for a low energy gamma-emitting stent in a heterogeneous medium is described. The method is based on the Sievert model which is adapted to the dose-point-kernel (DPK) model to compute the dose distribution about filtered gamma sources (Sievert-DPK model). The new gamma stent model can take into a...

journal_title：Medical physics

authors： Janicki C,Duggan DM,Rahdert DA

更新日期：2001-07-01 00:00:00

abstract：PURPOSE:Urinary particles are particularly important parameters in clinical urinalysis, especially for the diagnosis of nephropathy. Therefore, it is highly important to precisely detect urinary particles in the clinical setting. However, artificial microscopy is subjective and time consuming, and various previous dete...

journal_title：Medical physics

authors： Li Q,Yu Z,Qi T,Zheng L,Qi S,He Z,Li S,Guan H

更新日期：2020-07-01 00:00:00

abstract：PURPOSE:Computed tomography (CT) and, in particular, cone beam CT (CBCT) have been increasingly used as a diagnostic tool in recent years. Patient motion during acquisition is common in CBCT due to long scan times. This results in degraded image quality and may potentially increase the number of retakes. Our aim was to...

journal_title：Medical physics

authors： Niebler S,Schömer E,Tjaden H,Schwanecke U,Schulze R

更新日期：2019-10-01 00:00:00

abstract：:A theoretical model is described for application in ultrasonic tissue characterization using a calibrated 2-D spectrum analysis method. This model relates 2-D spectra computed from ultrasonic backscatter signals to intrinsic physical properties of tissue microstructures, e.g., size, shape, and acoustic impedance. The ...

journal_title：Medical physics

authors： Liu T,Lizzi FL,Ketterling JA,Silverman RH,Kutcher GJ

更新日期：2007-03-01 00:00:00

abstract：:Administration of x-ray contrast agents during heart catheterization examination increases the absorbed radiation dose in tissue. To estimate the dose absorbed by the blood of children undergoing diagnostic heart catheterization and angiocardiography, a number of measurements and calculations were conducted. First, en...

journal_title：Medical physics

authors： Callisen HH,Norman A,Adams FH

更新日期：1979-11-01 00:00:00

abstract：PURPOSE:We have recently developed a dynamic tumor tracking irradiation system using Vero4DRT (MHI-Tm2 000). It is needed to create a 4D correlation model between a fiducial marker implanted near a tumor and an external surrogate as a function of time by continuously acquiring both fluoroscopy images and external surro...

journal_title：Medical physics

authors： Shiinoki T,Sawada A,Ishihara Y,Miyabe Y,Fujimoto T,Nakai T,Matsuo Y,Mizowaki T,Kokubo M,Hiraoka M

更新日期：2012-06-01 00:00:00

abstract：:An indirect flat-panel imager (FPI) with avalanche gain is being investigated for low-dose x-ray imaging. It is made by optically coupling a structured x-ray scintillator CsI(Tl) to an amorphous selenium (a-Se) avalanche photoconductor called HARP (high-gain avalanche rushing photoconductor). The final electronic imag...

journal_title：Medical physics

authors： Zhao W,Li D,Reznik A,Lui BJ,Hunt DC,Rowlands JA,Ohkawa Y,Tanioka K

更新日期：2005-09-01 00:00:00

abstract：PURPOSE:To develop a new design of an x-ray beam shaper for helical computed tomography (CT) that increases the dose utilization. METHODS:For typical reconstruction algorithms in helical CT, different data are utilized with different weights during back-projection. In particular, data of the outer detector rows, i.e.,...

journal_title：Medical physics

authors： Köhler T,Brendel B,Proksa R

更新日期：2011-07-01 00:00:00

abstract：:Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides 137Cs, 125I, 192Ir, 103Pd, and 169Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of pha...

journal_title：Medical physics

authors： Melhus CS,Rivard MJ

更新日期：2006-06-01 00:00:00

abstract：PURPOSE:There are growing expectations that imaging biomarkers for tumor therapeutic drug response assessment will speed up preclinical testing of anticancer drugs in rodent models. The only imaging biomarker presently approved by the U.S. Food and Drug Administration is tumor size measurement based on either World Hea...

journal_title：Medical physics

authors： Lee YC,Goins BA,Fullerton GD

更新日期：2010-09-01 00:00:00

abstract：PURPOSE:The present study was conducted to investigate salivary iodine kinetics and dosimetry during repeated courses of radioiodine ((131)I) therapy for differentiated thyroid cancer (DTC). Such data could provide a better understanding of the mechanisms of (131)I induced salivary toxicity and help to develop appropri...

journal_title：Medical physics

authors： Liu B,Huang R,Kuang A,Zhao Z,Zeng Y,Wang J,Tian R

更新日期：2011-10-01 00:00:00

abstract：PURPOSE:The nonlocal influence from distant magnetization will affect the magnetic field at a voxel in question. Existing reports on BOLD simulation only consider vasculature inside a single voxel, thus omitting the contribution from the surrounding regions. In this article, the authors study the effect of the surround...

journal_title：Medical physics

authors： Chen Z,Caprihan A,Calhoun V

更新日期：2010-04-01 00:00:00

abstract：:The radiation dose to the lungs from 133Xe in lung air is directly proportional to the time integral of 133Xe concentration; i.e., the cumulated concentration in the lungs. Using kinetic models developed to fit clinical observations, we have studied the effect of retention on cumulated concentration in lung air. The m...

journal_title：Medical physics

authors： Watson EE,Cloutier RJ

更新日期：1977-11-01 00:00:00

abstract：PURPOSE:To develop a probabilistic treatment planning (PTP) method which is robust to systematic patient setup errors and to compare PTP plans with plans generated using a planning target volume (PTV) margin optimized to give the same target coverage probability as the PTP plan. METHODS:Plans adhering to the RTOG-0126...

journal_title：Medical physics

authors： Moore JA,Gordon JJ,Anscher M,Silva J,Siebers JV

更新日期：2012-02-01 00:00:00

abstract：PURPOSE:This article aims to introduce a novel algorithm for fast beam angle selection in intensity modulated radiotherapy (IMRT). METHODS:The algorithm models the optimization problem as a beam angle ranking problem and chooses suitable beam angles according to their rank. A new parameter called "beam intensity profi...

journal_title：Medical physics

authors： Vaitheeswaran R,Narayanan VK,Bhangle JR,Nirhali A,Kumar N,Basu S,Maiya V

更新日期：2010-12-01 00:00:00

abstract：PURPOSE:In this article, the authors propose a new gold standard data set for the validation of two-dimensional/three-dimensional (2D/3D) and 3D/3D image registration algorithms. METHODS:A gold standard data set was produced using a fresh cadaver pig head with attached fiducial markers. The authors used several imagin...

journal_title：Medical physics

authors： Pawiro SA,Markelj P,Pernus F,Gendrin C,Figl M,Weber C,Kainberger F,Nöbauer-Huhmann I,Bergmeister H,Stock M,Georg D,Bergmann H,Birkfellner W

更新日期：2011-03-01 00:00:00

abstract：PURPOSE:The segmentation accuracy of medical images was improved by increasing the number of training samples using a local image warping technique. The performance of the proposed method was evaluated in the segmentation of breast masses, prostate and brain tumors, and lung nodules. METHODS:We propose a simple data a...

journal_title：Medical physics

authors： Liu H,Cao H,Song E,Ma G,Xu X,Jin R,Liu T,Liu L,Liu D,Hung CC

更新日期：2020-12-10 00:00:00

abstract：:Two or more angiograms are being used frequently in medical imaging to reconstruct locations in three-dimensional (3D) space, e.g., for reconstruction of 3D vascular trees, implanted electrodes, or patient positioning. A number of techniques have been proposed for this task. In this simulation study, we investigate th...

journal_title：Medical physics

authors： Dmochowski J,Hoffmann KR,Singh V,Xu J,Nazareth DP

更新日期：2005-09-01 00:00:00

abstract：:The authors report on the imaging capabilities of a mammographic system demonstrator based on GaAs pixel detectors operating in single photon counting (SPC) mode. The system imaging performances have been assessed by means of the transfer functions: The modulation transfer function (MTF), the normalized noise power sp...

journal_title：Medical physics

authors： Amendolia SR,Bisogni MG,Delogu P,Fantacci ME,Paternoster G,Rosso V,Stefanini A

更新日期：2009-04-01 00:00:00