Optimizing wavelength choice for quantitative optoacoustic imaging using the Cramer-Rao lower bound.

abstract：:In this paper, we investigate an off-line strategy to incorporate inter-fraction organ motion in IMRT treatment planning. It was suggested that inverse planning could be based on a probability distribution of patient geometries instead of a single snap shot. However, this concept is connected to two intrinsic problems...

journal_title：Physics in medicine and biology

authors： Unkelbach J,Oelfke U

更新日期：2004-09-07 00:00:00

abstract：:Coherent x-rays from synchrotron sources are increasingly used in non-conventional radiological techniques ('phase-contrast' radiology). Our experiments demonstrate that by using white (unmonochromatic) radiation and a time-resolving system, it is possible to image microscopic details of moving blood vessels in differ...

journal_title：Physics in medicine and biology

authors： Hwu Y,Tsai WL,Je JH,Seol SK,Kim B,Groso A,Margaritondo G,Lee KH,Seong JK

更新日期：2004-02-21 00:00:00

abstract：:An important aspect of robotic radiation therapy is active compensation of target motion. Recently, ultrasound has been proposed to obtain real-time volumetric images of abdominal organ motion. One approach to realize flexible probe placement throughout the treatment fraction is based on a robotic arm holding the ultr...

journal_title：Physics in medicine and biology

authors： Schlüter M,Fürweger C,Schlaefer A

更新日期：2019-10-04 00:00:00

abstract：:It has been demonstrated that gas-filled microbubble contrast agents, based on their volume changes, can serve as pressure probes in an MR field. It was recently reported that such an MR-based pressure measurement with microbubbles at 1.5 T must make use of microbubbles that have a volumetric magnetic susceptibility d...

journal_title：Physics in medicine and biology

authors： Dharmakumar R,Plewes DB,Wright GA

更新日期：2005-10-21 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：:A multimodal micro-computed tomography (CT) and multi-spectral structured light imaging (SLI) system is introduced and systematically analyzed to test its feasibility to aid in margin delineation during breast conserving surgery (BCS). Phantom analysis of the micro-CT yielded a signal-to-noise ratio of 34, a contrast ...

journal_title：Physics in medicine and biology

authors： McClatchy DM,Rizzo EJ,Meganck J,Kempner J,Vicory J,Wells WA,Paulsen KD,Pogue BW

更新日期：2017-11-10 00:00:00

abstract：:We developed an anatomy-guided 4D closed-form algorithm to directly reconstruct parametric images from projection data for (nearly) irreversible tracers. Conventional methods consist of individually reconstructing 2D/3D PET data, followed by graphical analysis on the sequence of reconstructed image frames. The propose...

journal_title：Physics in medicine and biology

authors： Tang J,Kuwabara H,Wong DF,Rahmim A

更新日期：2010-08-07 00:00:00

abstract：:It has been reported that acoustic waves are generated when a high-energy pulsed proton beam is deposited in a small volume within tissue. One possible application of proton-induced acoustics is to get real-time feedback for intra-treatment adjustments by monitoring such acoustic waves. A high spatial resolution in ul...

journal_title：Physics in medicine and biology

authors： Kipergil EA,Erkol H,Kaya S,Gulsen G,Unlu MB

更新日期：2017-06-21 00:00:00

abstract：:The use of deformable image registration methods in the context of adaptive radiotherapy leads to uncertainties in the simulation of the administered dose distributions during the treatment course. Evaluation of these methods is a prerequisite to decide if a plan adaptation will improve the individual treatment. Curre...

journal_title：Physics in medicine and biology

authors： Teske H,Bartelheimer K,Meis J,Bendl R,Stoiber EM,Giske K

更新日期：2017-06-21 00:00:00

abstract：:Models of the electrical properties of biological tissue have been the subject of many studies. These models have sought to explain aspects of the dielectric dispersion of tissue. This paper develops a mathematical model of the complex permittivity of tissue as a function of frequency f, in the range 10(4) < f < 10(7)...

journal_title：Physics in medicine and biology

authors： Smye SW,Evans CJ,Robinson MP,Sleeman BD

更新日期：2007-12-07 00:00:00

abstract：:Hair loss is a feared side effect of chemotherapy treatment. It may be prevented by cooling the scalp during administration of cytostatics. The supposed mechanism is that by cooling the scalp, both temperature and perfusion are diminished, affecting drug supply and drug uptake in the hair follicle. However, the effect...

journal_title：Physics in medicine and biology

authors： Janssen FE,Van Leeuwen GM,Van Steenhoven AA

更新日期：2005-09-07 00:00:00

abstract：:A new mathematical model of the head has been constructed from a set of serial MRI slices from one subject. Finite-difference time-domain (FDTD) calculations of the specific energy absorption rate (SAR) have been performed on this model with a 2 mm resolution for a generic mobile communication transceiver represented ...

journal_title：Physics in medicine and biology

authors： Dimbylow PJ,Mann SM

更新日期：1994-10-01 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 treatment delivery time of intensity-modulated radiation therapy (IMRT) with a multileaf collimator (MLC) is generally longer than that of conventional radiotherapy. In theory, removing the flattening filter from the treatment head may reduce the beam-on time by enhancing the output dose rate, and then reduce the ...

journal_title：Physics in medicine and biology

authors： Fu W,Dai J,Hu Y,Han D,Song Y

更新日期：2004-04-21 00:00:00

abstract：:The dosimetric measurement and modeling of small radiation treatment fields (<2 × 2 cm2) are difficult to perform and prone to error. Measurements of small fields are often adversely influenced by the properties of the detectors used to make them. The dosimetric properties of small fields have been difficult to accura...

journal_title：Physics in medicine and biology

authors： Hundertmark B,Sterpin E,Mackie T

更新日期：2011-06-21 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：:For angiography using synchrotron radiation we measured the absorbed dose distribution in inhomogeneous phantoms with thin LiF:Mg, Cu, P, LiF:Mg, Ti thermoluminescent dosimeters (TLDs) in tissue and lung substitutes, and with Mg2SiO4:Tb TLDs in bone substitute for 33.32 keV monoenergetic photons from synchrotron radia...

journal_title：Physics in medicine and biology

authors： Nariyama N,Namito Y,Ban S,Hirayama H

更新日期：2001-03-01 00:00:00

abstract：:To investigate the profile measurement capabilities of an IBA-Dosimetry scintillation detector and to assess its feasibility for determining the low-intensity tails of pencil-beam scanning spots, the responses of the scintillation detector and Gafchromic EBT2 film to a 115 MeV proton spot were measured in-air at the i...

journal_title：Physics in medicine and biology

authors： Lin L,Ainsley CG,Mertens T,De Wilde O,Talla PT,McDonough JE

更新日期：2013-06-21 00:00:00

abstract：:We find the dose distribution that maximizes the tumour control probability (TCP) for a fixed mean tumour dose per fraction. We consider a heterogeneous tumour volume having a radiation response characterized by the linear quadratic model with heterogeneous radiosensitivity and repopulation rate that may vary in time....

journal_title：Physics in medicine and biology

authors： Levin-Plotnik D,Hamilton RJ

更新日期：2004-02-07 00:00:00

abstract：:This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical obs...

journal_title：Physics in medicine and biology

authors： Lee TS,Frey EC,Tsui BM

更新日期：2015-04-07 00:00:00

abstract：:We propose and evaluate the performance of an improved preclinical positron emission tomography (PET) scanner design, referred to as Polaroid-PET, consisting of a detector equipped with a layer of horizontal Polaroid to filter scintillation photons with vertical polarization. This makes it possible to improve the spat...

journal_title：Physics in medicine and biology

authors： Sanaat A,Ashrafi-Belgabad A,Zaidi H

更新日期：2020-12-02 00:00:00

abstract：:Due to high noise levels in the voxel kinetics, development of reliable parametric imaging algorithms remains one of most active areas in dynamic brain PET imaging, which in the vast majority of cases involves receptor/transporter studies with reversibly binding tracers. As such, the focus of this work has been to dev...

journal_title：Physics in medicine and biology

authors： Rahmim A,Zhou Y,Tang J,Lu L,Sossi V,Wong DF

更新日期：2012-02-07 00:00:00

abstract：:The energy dependence of the luminance ratio due to scattered and primary radiation has been determined for four types of X-ray intensifying screens. A water phantom of 30 cm X 30 cm X 20 cm was used as the scattering medium. Ten narrow band X-ray spectra were used as incident radiation: the mean energies of these spe...

journal_title：Physics in medicine and biology

authors： Koedooder K,Venema HW

更新日期：1984-10-01 00:00:00

abstract：:The aim of the study is to assess the staging value of the tumor heterogeneity characterized by texture features and other commonly used semi-quantitative indices extracted from (18)F-FDG PET images of cervical cancer (CC) patients. Forty-two patients suffering CC at different stages were enrolled in this study. First...

journal_title：Physics in medicine and biology

authors： Mu W,Chen Z,Liang Y,Shen W,Yang F,Dai R,Wu N,Tian J

更新日期：2015-07-07 00:00:00

abstract：:Few quantitative data are available on the kinetics of polymerization reactions in polymer gel (PAG) dosimeters and their long-term stability. Post-irradiation polymerization reactions have been found to continue for several weeks, posing questions regarding dosimeter stability and its achievement. In this paper we re...

journal_title：Physics in medicine and biology

authors： McJury M,Oldham M,Leach MO,Webb S

更新日期：1999-08-01 00:00:00

abstract：:Magnetic particle imaging is a new approach to visualizing magnetic nanoparticles. It is capable of 3D real-time in vivo imaging of particles injected into the blood stream and is a candidate for medical imaging applications. To date, only one particle type has been imaged at a time, however, the ability to separate s...

journal_title：Physics in medicine and biology

authors： Rahmer J,Halkola A,Gleich B,Schmale I,Borgert J

更新日期：2015-03-07 00:00:00

abstract：:Energy and angular distributions of electron beams with different energies were simulated by Monte Carlo calculations. These beams were generated by the NOVAC7 system (Hitesys, Italy), a mobile electron accelerator specifically dedicated to intra-operative radiation therapy (IORT). The electron beam simulations were v...

journal_title：Physics in medicine and biology

authors： Pimpinella M,Mihailescu D,Guerra AS,Laitano RF

更新日期：2007-10-21 00:00:00

abstract：BACKGROUND:During transcranial electrical stimulation (tES), including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), current density concentration around the electrode edges that is predicted by simplistic skin models does not match experimental observations of ...

journal_title：Physics in medicine and biology

authors： Khadka N,Bikson M

更新日期：2020-09-11 00:00:00

abstract：:Quantifying the retention or washout of (99m)Tc-Sestamibi (MIBI) in breast tumours in vivo may provide a basis for predicting the chemotherapy response. The aim of this study is to investigate the variations and limitations of the different methods used to quantify these parameters. A phantom was developed that allowe...

journal_title：Physics in medicine and biology

authors： Marshall C,Griffiths PA

更新日期：2005-05-07 00:00:00

abstract：:Treatment planning based on probability distribution function (PDF) of patient geometries has been shown a potential off-line strategy to incorporate organ motion, but the application of such approach highly depends upon the reproducibility of the PDF. In this paper, we investigated the dependences of the PDF reproduc...

journal_title：Physics in medicine and biology

authors： Cai J,Read PW,Altes TA,Molloy JA,Brookeman JR,Sheng K

更新日期：2007-01-21 00:00:00