Three-dimensional cellular-level imaging using full-field optical coherence tomography.

abstract：:Gel dosimetry based on magnetic resonance imaging (MRI) has previously been shown to provide verification of calculated dose distributions in soft tissue equivalent homogeneous phantoms. This study demonstrates how measurements of dose distribution can also be achieved in a phantom containing porous, lung-equivalent, ...

journal_title：Physics in medicine and biology

authors： Olberg S,Skretting A,Bruland O,Olsen DR

更新日期：2000-10-01 00:00:00

abstract：:Planning of radiotherapy is often difficult due to restrictions on morphological images. New imaging techniques enable the integration of biological information into treatment planning and help to improve the detection of vital and aggressive tumour areas. This might improve clinical outcome. However, nowadays morphol...

journal_title：Physics in medicine and biology

authors： Neff T,Kiessling F,Brix G,Baudendistel K,Zechmann C,Giesel FL,Bendl R

更新日期：2005-09-07 00:00:00

abstract：:The biological mechanisms of platelet destruction must be correctly identified before platelet survival curves can be interpreted. This report develops a theory of platelet destruction which is compared with experiments performed on platelets labelled with the radioactive isotope 51Cr. Platelet destruction rate is a c...

journal_title：Physics in medicine and biology

authors： Trowbridge EA,Martin JF

更新日期：1983-12-01 00:00:00

abstract：:Dynamic modulation can be affected by inaccuracies when the required acceleration is larger than the highest allowed by the mechanical characteristics of the whole apparatus. In this study, inertia effects have been investigated with regard to the single absorber 1D modulation, analysing primarily how the acceleration...

journal_title：Physics in medicine and biology

authors： Corletto D,Broggi S,Fiorino C,Mangili P,Calandrino R,Lev A,Gennari D,Rudello F

更新日期：1999-11-01 00:00:00

abstract：:A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is incorporated into a grow...

journal_title：Physics in medicine and biology

authors： Warman JM,de Haas MP,Luthjens LH

更新日期：2009-05-21 00:00:00

abstract：:In x-ray based imaging of the breast, contrast between fibroglandular (Fg) tissue and adipose (Ad) tissue is a source of anatomic noise. The goal of this work was to validate by simulation and experiment a mathematical framework for modelling the Fg component of anatomic noise in digital mammograpy (DM) and dual-energ...

journal_title：Physics in medicine and biology

authors： Tanguay J,Lalonde R,Bjarnason TA,Yang CJ

更新日期：2019-10-23 00:00:00

abstract：:The absolute dose rate around beta sources for intravascular brachytherapy was measured with thin thermoluminescent (TL) dosimeters and radiochromic film. The calibration of these dosimeters was performed at the dose maximum in a 6 MeV electron beam of a linear accelerator. Compared to the values given by the manufact...

journal_title：Physics in medicine and biology

authors： Piessens M,Reynaert N

更新日期：2000-08-01 00:00:00

abstract：:We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic co...

journal_title：Physics in medicine and biology

authors： Horas JA,Olguin OR,Rizzotto MG

更新日期：2005-04-21 00:00:00

abstract：:Avoiding toxicities in radiotherapy requires the knowledge of tolerable organ doses. For new, experimental fractionation schemes (e.g. hypofractionation) these are typically derived from traditional schedules using the biologically effective dose (BED) model. In this report we investigate the difficulties of establish...

journal_title：Physics in medicine and biology

authors： Perkó Z,Bortfeld T,Hong T,Wolfgang J,Unkelbach J

更新日期：2018-02-05 00:00:00

abstract：:Monte Carlo simulation provides a valuable tool in performance assessment and optimization of system design parameters for PET scanners. SimSET is a popular Monte Carlo simulation toolkit that features fast simulation time, as well as variance reduction tools to further enhance computational efficiency. However, SimSE...

journal_title：Physics in medicine and biology

authors： Poon JK,Dahlbom ML,Casey ME,Qi J,Cherry SR,Badawi RD

更新日期：2015-02-07 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：:An expression for the noise power spectrum of images reconstructed by the discrete filtered backprojection algorithm has been derived. The formulation explicitly includes sampling within the projections, angular sampling, and the two-dimensional sampling implicit in the discrete representation of the image. The effect...

journal_title：Physics in medicine and biology

authors： Kijewski MF,Judy PF

更新日期：1987-05-01 00:00:00

abstract：:This study presents the computational dosimetry of contact currents for grounded and ungrounded human models. The uncertainty of the quasi-static (QS) approximation of the in situ electric field induced in a grounded/ungrounded human body due to the contact current is first estimated. Different scenarios of cylindrica...

journal_title：Physics in medicine and biology

authors： Chan KH,Hattori J,Laakso I,Hirata A,Taki M

更新日期：2013-08-07 00:00:00

abstract：:We have developed an impedance magnetocardiogram (IMCG) system to detect the change of magnetic field corresponding to changes in blood volume in the heart. A low magnetic field from the electrical activity of the human heart--the so-called magnetocardiogram (MCG)--can be simultaneously detected by using this system. ...

journal_title：Physics in medicine and biology

authors： Kandori A,Miyashita T,Suzuki D,Yokosawa K,Tsukada K

更新日期：2001-02-01 00:00:00

abstract：:The standard mammogram form (SMF) representation of an x-ray mammogram is a standardized, quantitative representation of the breast from which the volume of non-fat tissue and breast density can be easily estimated, both of which are of significant interest in determining breast cancer risk. Previous theoretical analy...

journal_title：Physics in medicine and biology

authors： Highnam R,Pan X,Warren R,Jeffreys M,Davey Smith G,Brady M

更新日期：2006-06-07 00:00:00

abstract：:Charge-coupled devices (CCDs) coupled to scintillation crystals can be used for high-resolution imaging with x-rays and gamma rays. When the CCD images can be read out fast enough, the energy and interaction position of individual gamma quanta can be estimated by a real-time image analysis of the scintillation light f...

journal_title：Physics in medicine and biology

authors： Heemskerk JW,Westra AH,Linotte PM,Ligtvoet KM,Zbijewski W,Beekman FJ

更新日期：2007-04-21 00:00:00

abstract：:Modelling of inhaled particle deposition in the lungs potentially offers data relevant to assessing hazards from toxic inhaled particles, to studying mucus clearance or lung permeability by aerosol techniques, and to achieving better utilisation of drugs administered as aerosols. Analysis of published modelling studie...

journal_title：Physics in medicine and biology

authors： Agnew JE,Pavia D,Clarke SW

更新日期：1984-07-01 00:00:00

abstract：:We present a method based on spectral theory for the shape analysis of carpal bones of the human wrist. We represent the cortical surface of the carpal bone in a coordinate system based on the eigensystem of the two-dimensional Helmholtz equation. We employ a metric--global point signature (GPS)--that exploits the sca...

journal_title：Physics in medicine and biology

authors： Chaudhari AJ,Leahy RM,Wise BL,Lane NE,Badawi RD,Joshi AA

更新日期：2014-02-21 00:00:00

abstract：:This study examines the effectiveness of a single, first-order Arrhenius process in accurately modelling the thermally induced changes in the optical properties, particularly the reduced scattering coefficient, mu(s)', and the absorption coefficient, mu(a), of ex vivo rat prostate. Recent work has shown that mu(s)' ca...

journal_title：Physics in medicine and biology

authors： Skinner MG,Everts S,Reid AD,Vitkin IA,Lilge L,Sherar MD

更新日期：2000-05-01 00:00:00

abstract：:We used a real-skull phantom head to investigate the performances of representative methods for EEG source localization when considering various head models. We describe several experiments using a montage with current sources located at multiple positions and orientations inside a human skull filled with a conductive...

journal_title：Physics in medicine and biology

authors： Baillet S,Riera JJ,Marin G,Mangin JF,Aubert J,Garnero L

更新日期：2001-01-01 00:00:00

abstract：:Fluorescence molecular imaging/tomography may play an important future role in preclinical research and clinical diagnostics. Time- and frequency-domain fluorescence imaging can acquire more measurement information than the continuous wave (CW) counterpart, improving the image quality of fluorescence molecular tomogra...

journal_title：Physics in medicine and biology

authors： Lu Y,Zhu B,Shen H,Rasmussen JC,Wang G,Sevick-Muraca EM

更新日期：2010-08-21 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：:The University of Washington (UW) Clinical Neutron Therapy System (CNTS) has been used to treat over 3300 patients. Treatment planning for these patients is currently performed using an MV x-ray model in Pinnacle® adapted to fit measurements of fast neutron output factors, wedge factors, depth-dose and lateral profile...

journal_title：Physics in medicine and biology

authors： Moffitt GB,Wootton LS,Hårdemark B,Sandison GA,Laramore GE,Parvathaneni U,Stewart RD

更新日期：2020-08-31 00:00:00

abstract：:Using a statistical (chi-square) test on simulated data and a realistic noise model derived from the system's hardware we study the performance of diffuse optical tomography systems for fluorescence imaging. We compare the predicted smallest size of detectable lesions at various positions in slab and cup geometry and ...

journal_title：Physics in medicine and biology

authors： Ziegler R,Brendel B,Rinneberg H,Nielsen T

更新日期：2009-01-21 00:00:00

abstract：:3D acquisition and reconstruction in positron emission tomography (PET) produce data with improved signal-to-noise ratios compared with conventional 2D slice-oriented methods. However, the sensitivity increase is accompanied by an increase in the number of scattered photons and random coincidences detected. This paper...

journal_title：Physics in medicine and biology

authors： Bailey DL,Meikle SR

更新日期：1994-03-01 00:00:00

abstract：:Inverse treatment planning in intensity modulated particle therapy (IMPT) with scanned carbon-ion beams is currently based on the optimization of RBE-weighted dose to satisfy requirements of target coverage and limited toxicity to organs-at-risk (OARs) and healthy tissues. There are many feasible IMPT plans that meet ...

journal_title：Physics in medicine and biology

authors： Burigo LN,Ramos-Méndez J,Bangert M,Schulte RW,Faddegon B

更新日期：2019-01-04 00:00:00

abstract：:Radiotherapy treatment planning is associated with uncertainties. Examples are uncertainties in the tumour location due to organ movement or the inter/intra observer variability in target definition. Different approaches to incorporate uncertainties into IMRT optimization have been proposed. In this note, we point out...

journal_title：Physics in medicine and biology

authors： Unkelbach J,Oelfke U

更新日期：2006-12-07 00:00:00

abstract：:The purpose of this study was to improve the performance of a small gamma camera, utilizing a NaI(Tl) plate and a 5" position sensitive PMT. We attempted to build a NaI(Tl) plate crystal system which retained all its advantages, while at the same time integrating some of the advantages inherent in an array-type scinti...

journal_title：Physics in medicine and biology

authors： Jeong MH,Choi Y,Chung YH,Song TY,Jung JH,Hong KJ,Min BJ,Choe YS,Lee KH,Kim BT

更新日期：2004-11-07 00:00:00

abstract：:In order to effectively utilize the prominent properties of heavy ions in radiotherapy, it is important to evaluate both the position of the field irradiated with incident ions and the absorbed dose distribution in a patient's body. One of the methods for this purpose is the utilization of the positron emitters produc...

journal_title：Physics in medicine and biology

authors： Inaniwa T,Kohno T,Tomitani T,Sato S

更新日期：2008-02-07 00:00:00

abstract：:Determining plaque vulnerability is critical when selecting the most suitable treatment for patients with atherosclerotic plaque. Currently, clinical non-invasive ultrasound-based methods for plaque characterization are limited to visual assessment of plaque morphology and new quantitative methods are needed. In this ...

journal_title：Physics in medicine and biology

authors： Widman E,Maksuti E,Larsson D,Urban MW,Bjällmark A,Larsson M

更新日期：2015-04-21 00:00:00