Shear wave elastography plaque characterization with mechanical testing validation: a phantom study.

abstract：:Intra-fractional motion is a concern during prostate radiation therapy, as it may cause deviations between planned and delivered radiation doses. Because accurate motion information during treatment delivery is critical to address dose deviation, we developed the projection marker matching method (PM3), a novel method...

journal_title：Physics in medicine and biology

authors： Chi Y,Rezaeian NH,Shen C,Zhou Y,Lu W,Yang M,Hannan R,Jia X

更新日期：2017-07-07 00:00:00

abstract：:The radiation used in hadrontherapy treatments interacts with the patient body producing secondary particles, either neutral or charged, that can be used for dose and Bragg peak monitoring and to provide a fast feedback on the treatment plans. Recent results obtained from the authors on simplified setups (mono-energet...

journal_title：Physics in medicine and biology

authors： Piersanti L,Bellini F,Bini F,Collamati F,De Lucia E,Durante M,Faccini R,Ferroni F,Fiore S,Iarocci E,La Tessa C,Marafini M,Mattei I,Patera V,Ortega PG,Sarti A,Schuy C,Sciubba A,Vanstalle M,Voena C

更新日期：2014-04-07 00:00:00

abstract：:We present a comparison of simulated low-frequency electromagnetic fields in the human body, calculated by means of the electro-quasistatic formulation. The geometrical data in these simulations were provided by an anatomically realistic, high-resolution human body model, while the dielectric properties of the various...

journal_title：Physics in medicine and biology

authors： Barchanski A,De Gersem H,Gjonaj E,Weiland T

更新日期：2005-10-07 00:00:00

abstract：:An analytical approximation for the scatter to primary dose ratio (SPR) on the central axis was validated against Monte Carlo results and experimental measurements for homogeneous and inhomogeneous phantoms. The analytical approximation only included first-order Compton scatter. The contribution to the total SPR from ...

journal_title：Physics in medicine and biology

authors： Ozard SR,Grein EE

更新日期：2001-06-01 00:00:00

abstract：:There are three ways to determine the spectrum of a clinical photon beam: direct measurement, modelling the source and reconstruction from ion-chamber measurements. We focus on reconstruction because the necessary equipment is readily available and it provides independent confirmation of source models for a given mach...

journal_title：Physics in medicine and biology

authors： Armbruster B,Hamilton RJ,Kuehl AK

更新日期：2004-11-21 00:00:00

abstract：:An x-ray fluorescence system with a synchrotron radiation source was used to quantify the levels of iron, copper and zinc in breast tissue specimens. Healthy tissue and breast carcinomas were investigated as an aid to understanding the mechanisms of breast cancer and as a possible complementary diagnostic tool. Eighty...

journal_title：Physics in medicine and biology

authors： Geraki K,Farquharson MJ,Bradley DA

更新日期：2002-07-07 00:00:00

abstract：:The function of the placenta is challenging to characterize and as a result is understudied, despite the growing awareness of the impact of the placental environment on human health and development. Medical imaging has the potential to improve our ability to screen for diseases associated with placental insufficiency,...

journal_title：Physics in medicine and biology

authors： Wu C,Bayer CL

更新日期：2018-07-09 00:00:00

abstract：:The purpose of this work is to develop and test a method to estimate the relative and absolute absorbed radiation dose from axial and spiral CT scans using a Monte Carlo approach. Initial testing was done in phantoms and preliminary results were obtained from a standard mathematical anthropomorphic model (MIRD V) and ...

journal_title：Physics in medicine and biology

authors： Jarry G,DeMarco JJ,Beifuss U,Cagnon CH,McNitt-Gray MF

更新日期：2003-08-21 00:00:00

abstract：:The Jacobian of the deformation field of elastic registration between images taken during radiotherapy is a measure of inter-fraction local deformation. The histogram of the Jacobian values (Jac) within an organ was introduced (JVH-Jacobian-volume-histogram) and first applied in quantifying parotid shrinkage. MVCTs of...

journal_title：Physics in medicine and biology

authors： Fiorino C,Maggiulli E,Broggi S,Liberini S,Cattaneo GM,Dell'oca I,Faggiano E,Di Muzio N,Calandrino R,Rizzo G

更新日期：2011-06-07 00:00:00

abstract：:Irreversible electroporation (IRE) is a minimally invasive tumor therapy using pulsed electric field with high intensity while the important tissues such as blood vessel, bile duct, and nerve are preserved. In addition to ablation area, reversible electroporation (RE) region is also generated using needle electrodes f...

journal_title：Physics in medicine and biology

authors： Lv Y,Tang X,Peng W,Cheng X,Chen S,Yao C

更新日期：2020-10-14 00:00:00

abstract：:Numerous studies have reported the measurements of the dielectric properties of the skin. Clarifying the manner in which the human body interacts with electromagnetic waves is essential for medical research and development, as well as for the safety assessment of electromagnetic wave exposure. The skin comprises sever...

journal_title：Physics in medicine and biology

authors： Sasaki K,Wake K,Watanabe S

更新日期：2014-08-21 00:00:00

abstract：:The measurement of beam data for dynamic wedge dosimetry requires the integration of radiation dose at points across the radiation field during the dose delivery. The different measurement techniques required when using a linear diode array to measure beam profiles and when using ionization chambers to measure depth d...

journal_title：Physics in medicine and biology

authors： Bidmead AM,Garton AJ,Childs PJ

更新日期：1995-03-01 00:00:00

abstract：:The variety of treatment options for cancer patients has increased significantly in recent years. Not only do we combine radiation with surgery and chemotherapy, new therapeutic approaches such as immunotherapy and targeted therapies are starting to play a bigger role. Physics has made significant contributions to rad...

journal_title：Physics in medicine and biology

authors： Grassberger C,Paganetti H

更新日期：2016-11-07 00:00:00

abstract：:Enabling automated pipelines, image analysis and big data methodology in cancer clinics requires thorough understanding of the data. Automated quality assurance steps could improve the efficiency and robustness of these methods by verifying possible data biases. In particular, in head and neck (H&N) computed-tomograph...

journal_title：Physics in medicine and biology

authors： Welch ML,McIntosh C,Purdie TG,Wee L,Traverso A,Dekker A,Haibe-Kains B,Jaffray DA

更新日期：2020-01-10 00:00:00

abstract：:A method is presented to predict beam profiles and outputs for wedged asymmetric fields defined by independent collimator jaws allowing fast generation of beam profiles whilst requiring very little additional data to that already used by most treatment planning systems in generating symmetric field isodoses. Symmetric...

journal_title：Physics in medicine and biology

authors： Millin AE,Smith CW

更新日期：1994-01-01 00:00:00

abstract：:We study threshold-driven optimization methodology for automatically generating a treatment plan that is motivated by a reference DVH for IMRT treatment planning. We present a framework for threshold-driven optimization for reference-based auto-planning (TORA). Commonly used voxel-based quadratic penalties have two co...

journal_title：Physics in medicine and biology

authors： Long T,Chen M,Jiang S,Lu W

更新日期：2018-02-08 00:00:00

abstract：:Complex intra-fractional motion and deformation of the liver significantly impacts the accuracy of delivered dose in radiotherapy. It limits margin reduction, dose escalation and normal tissue sparing. A critical component of motion management is to accurately reconstruct tumor motion. In this study, we developed a si...

journal_title：Physics in medicine and biology

authors： Chi Y,Shen C,Li B,Zhang Y,Yang M,Folkert M,Jia X

更新日期：2019-11-21 00:00:00

abstract：:We combine two near-infrared diffuse optical techniques to study variations of blood flow, haemoglobin concentration, and blood oxygen saturation in the functioning rat brain. Diffuse correlation spectroscopy (or flowmetry) monitors changes in the cerebral blood flow, without the use of the principles of tracer cleara...

journal_title：Physics in medicine and biology

authors： Cheung C,Culver JP,Takahashi K,Greenberg JH,Yodh AG

更新日期：2001-08-01 00:00:00

abstract：:The theory of task-based assessment of image quality is reviewed in the context of imaging with ionizing radiation, and objective figures of merit (FOMs) for image quality are summarized. The variation of the FOMs with the task, the observer and especially with the mean number of photons recorded in the image is discu...

journal_title：Physics in medicine and biology

authors： Barrett HH,Myers KJ,Hoeschen C,Kupinski MA,Little MP

更新日期：2015-01-21 00:00:00

abstract：:Diffuse optical tomography is an imaging technique whereby spatial maps of absorption and scattering coefficients are derived from the characteristics of multiply scattered light transmitted through the object. The system described here used four intensity-modulated light sources and measurements of the intensity and ...

journal_title：Physics in medicine and biology

authors： Pogue BW,Patterson MS,Jiang H,Paulsen KD

更新日期：1995-10-01 00:00:00

abstract：:Gold nanoparticles (GNPs) have shown potential in recent years as a means of therapeutic dose enhancement in radiation therapy. However, a major challenge in moving towards clinical implementation is the exact characterisation of the dose enhancement they provide. Monte Carlo studies attempt to explore this property, ...

journal_title：Physics in medicine and biology

authors： Koger B,Kirkby C

更新日期：2016-03-07 00:00:00

abstract：:A finite element thermal model of the head has been developed to calculate temperature rises generated in the brain by radiation from cellular telephones and similar electromagnetic devices. A 1 mm resolution MRI dataset was segmented semiautomatically, assigning each volume element to one of ten tissue types. A finit...

journal_title：Physics in medicine and biology

authors： Wainwright P

更新日期：2000-08-01 00:00:00

abstract：:Poly(vinyl alcohol) cryogel, PVA-C, is presented as a tissue-mimicking material, suitable for application in magnetic resonance (MR) imaging and ultrasound imaging. A 10% by weight poly(vinyl alcohol) in water solution was used to form PVA-C, which is solidified through a freeze-thaw process. The number of freeze-thaw...

journal_title：Physics in medicine and biology

authors： Surry KJ,Austin HJ,Fenster A,Peters TM

更新日期：2004-12-21 00:00:00

abstract：:A novel transmission detector (IBA Dosimetry, Germany) developed as an IMRT quality assurance tool, intended for in vivo patient dose measurements, is studied here. The goal of this investigation is to use Monte Carlo techniques to characterize treatment beam parameters in the presence of the detector and to compare t...

journal_title：Physics in medicine and biology

authors： Asuni G,Jensen JM,McCurdy BM

更新日期：2011-02-21 00:00:00

abstract：:This study investigates the oxygen mass transport in the region around the human carotid bifurcation, particularly addressing the effects of bifurcation geometry and pulsatile blood flow on the oxygen transport between the blood flow and artery wall tissue, coupled with the metabolic oxygen consumption and oxygen diff...

journal_title：Physics in medicine and biology

authors： Tada S

更新日期：2010-07-21 00:00:00

abstract：:A single photon absorptiometry method to measure the arterial concentration of injected iodinated contrast agent was developed. A prototype absorptiometry unit was built which consists of either a square or circular cross section acrylic (polymethylmethacrylate) cuvette connected to an arterial catheter at one end and...

journal_title：Physics in medicine and biology

authors： Yeung WT,Lee TY,Del Maestro RF,Kozak R,Bennett JD,Brown T

更新日期：1992-09-01 00:00:00

abstract：:Respiratory gating based on external surrogates is performed in many clinics. We have developed a new technique for treatment verification using an electronic portal imaging device (EPID) in cine mode for gated 3D conformal therapy. Implanted radiopaque fiducial markers inside or near the target are required for this ...

journal_title：Physics in medicine and biology

authors： Berbeco RI,Neicu T,Rietzel E,Chen GT,Jiang SB

更新日期：2005-08-21 00:00:00

abstract：:The goals of this study were (1) to characterize the optical artefacts affecting measurement accuracy in a volumetric liquid scintillator detector, and (2) to develop methods to correct for these artefacts. The optical artefacts addressed were photon scattering, refraction, camera perspective, vignetting, lens distort...

journal_title：Physics in medicine and biology

authors： Robertson D,Hui C,Archambault L,Mohan R,Beddar S

更新日期：2014-01-06 00:00:00

abstract：:The combined build-up and attenuation factor, B exp (-mu r), of point isotropic photon sources in a water medium has been calculated using the Monte Carlo method, for energies (20-1500 keV) and distances (1-10 cm) relevant in brachytherapy. For the transport of photons and electrons, up-to-date and self-consistent tot...

journal_title：Physics in medicine and biology

authors： Angelopoulos A,Perris A,Sakellariou K,Sakelliou L,Sarigiannis K,Zarris G

更新日期：1991-06-01 00:00:00

abstract：:We propose a retrospective respiratory gating algorithm to generate dynamic CT studies. To this end, we compared three different methods of extracting the respiratory signal from the projections of small-animal cone-beam computed tomography (CBCT) scanners. Given a set of frames acquired from a certain axial angle, su...

journal_title：Physics in medicine and biology

authors： Chavarrías C,Vaquero JJ,Sisniega A,Rodríguez-Ruano A,Soto-Montenegro ML,García-Barreno P,Desco M

更新日期：2008-09-07 00:00:00