Influence of vascular normalization on interstitial flow and delivery of liposomes in tumors.

abstract：:Calculating the dynamic properties of magnetization of single-domain particles is of great importance for the tomographic imaging modality known as magnetic particle imaging (MPI). Although the assumption of instantaneous thermodynamic equilibrium (Langevin function) after application of time-dependent magnetic fields...

journal_title：Physics in medicine and biology

authors： Weizenecker J

更新日期：2018-01-22 00:00:00

abstract：:Commercial TPSs typically model the tongue-and-groove (TG) by extending the projections of the leaf sides by a certain constant width. However, this model may produce discrepancies of as much as 7%-10% in the calculated average doses, especially for the High Definition multi-leaf collimator (MLC) (Hernandez et al 2017...

journal_title：Physics in medicine and biology

authors： Hernandez V,Vera-Sánchez JA,Vieillevigne L,Khamphan C,Saez J

更新日期：2018-12-10 00:00:00

abstract：:New organ dose conversion coefficients for coronary angiographic interventions are presented, as well as dose distributions and resulting maximal local dose conversion coefficients in the relevant organs. For the Monte Carlo based simulations, voxel models of the human anatomy were employed which represent the average...

journal_title：Physics in medicine and biology

authors： Schlattl H,Zankl M,Hausleiter J,Hoeschen C

更新日期：2007-08-07 00:00:00

abstract：:A transformation method was investigated for applying the MIRD absorbed fraction to internal dose calculations for an individual. The transformation method consists of two parts, transformation of the target organ mass, and of the distance between source and target organs. The variation of the specific absorbed fracti...

journal_title：Physics in medicine and biology

authors： Yamaguchi H,Kato Y,Shiragai A

更新日期：1975-07-01 00:00:00

abstract：:It seems likely that long term patency of small bore vascular prostheses is dependent upon, among other things, the mechanical properties of their walls. Arteries are visco-elastic but there is no accurate method of measuring the visco-elasticity of arterial substitutes in vivo. The most successful vascular substitute...

journal_title：Physics in medicine and biology

authors： Chapman BL,Charlesworth D

更新日期：1983-09-01 00:00:00

abstract：:The intra- and inter-batch accuracy and precision of MRI (polyacrylamide gelatin gel fabricated at atmospheric conditions) polymer gel dosimeters are assessed in full 3D. In the intra-batch study, eight spherical flasks were filled with the same polymer gel along with a set of test tubes that served as calibration pha...

journal_title：Physics in medicine and biology

authors： Vandecasteele J,De Deene Y

更新日期：2013-01-07 00:00:00

abstract：:Voxel phantoms are human models based on computed tomographic or magnetic resonance images obtained from high-resolution scans of a single individual. They consist of a huge number of volume elements (voxels) and are at the moment the most precise representation of the human anatomy. The purpose of this paper is to in...

journal_title：Physics in medicine and biology

authors： Petoussi-Henss N,Zanki M,Fill U,Regulla D

更新日期：2002-01-07 00:00:00

abstract：:Motion mitigation strategies are crucial for scanned particle therapy of mobile tumours in order to prevent geometrical target miss and interplay effects. We developed a patient-specific respiratory motion model based on simultaneously acquired time-resolved volumetric MRI and 2D abdominal ultrasound images. We presen...

journal_title：Physics in medicine and biology

authors： Giger AT,Krieger M,Jud C,Duetschler A,Salomir R,Bieri O,Bauman G,Nguyen D,Weber DC,Lomax AJ,Zhang Y,Cattin PC

更新日期：2020-07-28 00:00:00

abstract：:The stochastic nature of cavitation implies visualization of the cavitation cloud in real-time and in a discriminative manner for the safe use of focused ultrasound therapy. This visualization is sometimes possible with standard echography, but it strongly depends on the quality of the scanner, and is hindered by diff...

journal_title：Physics in medicine and biology

authors： Arnal B,Baranger J,Demene C,Tanter M,Pernot M

更新日期：2017-02-07 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：:A method to determine the spectrum of a clinical photon beam from measured depth-dose data is described. At shallow depths, where the range of Compton-generated electrons increases rapidly with photon energy, the depth dose provides the information to discriminate the spectral contributions. To minimize the influence ...

journal_title：Physics in medicine and biology

authors： Bloch P,Altschuler MD,Bjärngard BE,Kassaee A,McDonough J

更新日期：2000-01-01 00:00:00

abstract：:Measuring spin-spin relaxation times (T2) by quantitative MR imaging represents a potentially efficient tool to evaluate the physicochemical properties of various media. However, noise in MR images is responsible for uncertainties in the determination of T2 relaxation times, which limits the accuracy of parametric tis...

journal_title：Physics in medicine and biology

authors： Gensanne D,Josse G,Lagarde JM,Vincensini D

更新日期：2006-06-07 00:00:00

abstract：:The enormous advances in the understanding of human anatomy, physiology and pathology in recent decades have led to ever-improving methods of disease prevention, diagnosis and treatment. Many of these achievements have been enabled, at least in part, by advances in ionizing radiation detectors. Radiology has been tran...

journal_title：Physics in medicine and biology

authors： Seco J,Clasie B,Partridge M

更新日期：2014-10-21 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：:Intensive computation time is required to simulate images of electronic portal imaging device (EPID) using Monte Carlo (MC) technique, limiting the development of applications associated with EPID, such as mega-voltage cone-beam computed tomography (MV-CBCT). In this study, a fast, accurate simulation strategy for MV-...

journal_title：Physics in medicine and biology

authors： Shi M,Myronakis M,Jacobson M,Lehmann M,Ferguson D,Baturin P,Huber P,Fueglistaller R,Harris T,Lozano IV,Williams C,Morf D,Berbeco RI

更新日期：2020-07-06 00:00:00

abstract：:We have developed and tested an MR-compatible gamma probe to simultaneously obtain anatomical information and functional information during surgery. The probe consists of a probe head, an optical fibre bundle and a photo-multiplier tube (PMT). The NaI(T1) scintillator contained in the probe head is connected to a 7 m ...

journal_title：Physics in medicine and biology

authors： Yamamoto S,Kuroda K,Senda M

更新日期：2004-08-07 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：:This paper describes the algorithm and examines the performance of an intensity-modulated radiation therapy (IMRT) beam-angle optimization (BAO) system. In this algorithm successive sets of beam angles are selected from a set of predefined directions using a fast simulated annealing (FSA) algorithm. An IMRT beam-profi...

journal_title：Physics in medicine and biology

authors： Djajaputra D,Wu Q,Wu Y,Mohan R

更新日期：2003-10-07 00:00:00

abstract：:The coincidence time resolution (CTR) becomes a key parameter of 511 keV gamma detection in time of flight positron emission tomography (TOF-PET). This is because additional information obtained through timing leads to a better noise suppression and therefore a better signal to noise ratio in the reconstructed image. ...

journal_title：Physics in medicine and biology

authors： Nemallapudi MV,Gundacker S,Lecoq P,Auffray E,Ferri A,Gola A,Piemonte C

更新日期：2015-06-21 00:00:00

abstract：:Uncemented prosthetic joint implants used in orthopaedic surgery are usually coated with a porous surface to encourage bone ingrowth. Better contact between the endosteal bone and the porous surface improves ingrowth, and such contact may be increased if the joint further subsides into position in the first weeks foll...

journal_title：Physics in medicine and biology

authors： Berry E,Langkamer VG,Jackson PC,Snow M,Goddard PR,Wells PN

更新日期：1993-02-01 00:00:00

abstract：:Modern Monte Carlo codes allow for the calculation of ion chamber specific beam quality correction factors k(Q), which are needed for dosimetry in radiotherapy. While statistical (type A) uncertainties of the calculated data can be minimized sufficiently, the influence of systematic (type B) uncertainties is mostly un...

journal_title：Physics in medicine and biology

authors： Wulff J,Heverhagen JT,Zink K,Kawrakow I

更新日期：2010-08-21 00:00:00

abstract：:A general theory is presented for minimizing noise in linear dimension reduction of sequences of medical images when the factors and the covariance matrix and mean of the noise are given. A dimension reduction is optimal when all diagonal elements in the covariance matrix of the noise in the signal (factor) space are ...

journal_title：Physics in medicine and biology

authors： Hermansen F,Lammertsma AA

更新日期：1995-11-01 00:00:00

abstract：:Laser interstitial thermotherapy (LITT) is employed to destroy tumors in organs, and its outcome strongly depends on the temperature distribution inside the treated tissue. The recent introduction of computed tomography (CT) scan thermometry, based on the CT number dependence of the tissue with temperature, overcomes ...

journal_title：Physics in medicine and biology

authors： Schena E,Saccomandi P,Giurazza F,Caponero MA,Mortato L,Di Matteo FM,Panzera F,Del Vescovo R,Beomonte Zobel B,Silvestri S

更新日期：2013-08-21 00:00:00

abstract：:Intensity modulated proton radiotherapy (IMPT) can reduce the dose to critical structures by optimizing the distribution and intensity of individual pencil beams. The IMPT can be delivered by dynamically scanning a pencil beam with variable intensity and energy across the tumor target volume. The lateral penumbra of a...

journal_title：Physics in medicine and biology

authors： Safai S,Bortfeld T,Engelsman M

更新日期：2008-03-21 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：:A method using both patient geometric and dosimetric information was proposed to predict dose-volume histograms (DVHs) of organs at risk (OARs) for a nasopharyngeal cancer (NPC) intensity-modulated radiation therapy (IMRT) plan. A total of 106 nine-field IMRT NPC plans were used in this study. Twenty-six plans were ra...

journal_title：Physics in medicine and biology

authors： Jiao SX,Chen LX,Zhu JH,Wang ML,Liu XW

更新日期：2019-12-05 00:00:00

abstract：:In recent years, the Monte Carlo method has been used in a large number of research studies in radiation therapy. For applications such as treatment planning, it is essential to validate the dosimetric accuracy of the Monte Carlo simulations in heterogeneous media. The AAPM Report no 105 addresses issues concerning cl...

journal_title：Physics in medicine and biology

authors： Titt U,Sahoo N,Ding X,Zheng Y,Newhauser WD,Zhu XR,Polf JC,Gillin MT,Mohan R

更新日期：2008-08-21 00:00:00

abstract：:Image reconstruction of ultrasound computed tomography based on the wave equation is able to show much more structural details than simpler ray-based image reconstruction methods. However, to invert the wave-based forward model is computationally demanding. To address this problem, we develop an efficient fully learne...

journal_title：Physics in medicine and biology

authors： Zhao W,Wang H,Gemmeke H,van Dongen KWA,Hopp T,Hesser J

更新日期：2020-11-27 00:00:00

abstract：:In conventional gating approaches for positron emission tomography (PET), a single number of gates is predetermined for the whole field of view (FOV) regardless of spatially variant motion blurring effects, which compromises image quality by under-gating regions of large motion and over-gating static regions. To achie...

journal_title：Physics in medicine and biology

authors： Wang J,Dong Y,Li H,Feng T

更新日期：2018-08-10 00:00:00

abstract：:Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteri...

journal_title：Physics in medicine and biology

authors： Hoffmann AL,den Hertog D,Siem AY,Kaanders JH,Huizenga H

更新日期：2008-11-21 00:00:00