Computed temperature distributions around ectatic capillaries exposed to yellow (578 nm) laser light.

Abstract:

:We have numerically modelled the thermal effects of yellow (577 or 578 nm) light illumination on the ectatic blood vessels of port wine stains. We investigated the effect of the laser treatment parameters of light irradiance and illumination time on the extent of coagulation (coagulation thickness) of the endothelial cells of the ectatic vessels. We assumed that this coagulation is dependent on heating the cells to a critical temperature (coagulation temperature). We iteratively adjusted the treatment parameters so that the model vessels had a maximum temperature that did not exceed the boiling point of blood. Given the likely range of variation of coagulation temperature, coagulation thickness and vessel size, coagulation temperature was found to have the greatest effect on the treatment parameters. Variations in coagulation thickness had less influence, and the diameter of the ectatic vessel (typically in the 30-80 microns diameter range) had the least effect. The treatment parameters that have been shown clinically to cause purpura (e.g. 6-7 cm-2 in 360 microseconds) were also studied. The purpura seen by some workers using pulsed dye lasers is most likely to be the result of vaporisation of blood leading to the rupture of the vessel. We conclude that, in order to achieve coagulation with these short laser pulses, the choice of irradiance is critical.

journal_name

Phys Med Biol

authors

Pickering JW,Butler PH,Ring BJ,Walker EP

doi

10.1088/0031-9155/34/9/010

subject

Has Abstract

pub_date

1989-09-01 00:00:00

pages

1247-58

issue

9

eissn

0031-9155

issn

1361-6560

journal_volume

34

pub_type

杂志文章
  • Determination of elemental tissue composition following proton treatment using positron emission tomography.

    abstract::Positron emission tomography (PET) has been suggested as an imaging technique for in vivo proton dose and range verification after proton induced-tissue activation. During proton treatment, irradiated tissue is activated and decays while emitting positrons. In this paper, we assessed the feasibility of using PET imagi...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/58/11/3815

    authors: Cho J,Ibbott G,Gillin M,Gonzalez-Lepera C,Min CH,Zhu X,El Fakhri G,Paganetti H,Mawlawi O

    更新日期:2013-06-07 00:00:00

  • Accurate and efficient modeling of the detector response in small animal multi-head PET systems.

    abstract::In fully three-dimensional PET imaging, iterative image reconstruction techniques usually outperform analytical algorithms in terms of image quality provided that an appropriate system model is used. In this study we concentrate on the calculation of an accurate system model for the YAP-(S)PET II small animal scanner,...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/58/19/6713

    authors: Cecchetti M,Moehrs S,Belcari N,Del Guerra A

    更新日期:2013-10-07 00:00:00

  • A depth-encoding PET detector for high resolution PET using 1 mm SiPMs.

    abstract::A dual-ended readout PET detector based on two Hamamatsu 16 × 16 arrays of 1 × 1 mm2 SiPMs coupled to both ends of a 25 × 25 array of 0.69 × 0.69 × 20 mm3 polished LYSOs was evaluated in terms of flood histogram, energy resolution, timing resolution, and DOI resolution. The SiPM arrays have a pitch size of 1.2 mm. Eac...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/ab9fc9

    authors: Du J,Bai X,Cherry SR

    更新日期:2020-08-19 00:00:00

  • An exponential growth of computational phantom research in radiation protection, imaging, and radiotherapy: a review of the fifty-year history.

    abstract::Radiation dose calculation using models of the human anatomy has been a subject of great interest to radiation protection, medical imaging, and radiotherapy. However, early pioneers of this field did not foresee the exponential growth of research activity as observed today. This review article walks the reader through...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章,评审

    doi:10.1088/0031-9155/59/18/R233

    authors: Xu XG

    更新日期:2014-09-21 00:00:00

  • Effect of dominant features on neural network performance in the classification of mammographic lesions.

    abstract::Two different classifiers, an artificial neural network (ANN) and a hybrid system (one step rule-based method followed by an artificial neural network) have been investigated to merge computer-extracted features in the task of differentiating between malignant and benign masses. A database consisting of 65 cases (38 m...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/44/10/315

    authors: Huo Z,Giger ML,Metz CE

    更新日期:1999-10-01 00:00:00

  • Image reconstruction and scan configurations enabled by optimization-based algorithms in multispectral CT.

    abstract::Optimization-based algorithms for image reconstruction in multispectral (or photon-counting) computed tomography (MCT) remains a topic of active research. The challenge of optimization-based image reconstruction in MCT stems from the inherently non-linear data model that can lead to a non-convex optimization program f...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aa8a4b

    authors: Chen B,Zhang Z,Sidky EY,Xia D,Pan X

    更新日期:2017-11-02 00:00:00

  • In vitro double-integrating-sphere optical properties of tissues between 630 and 1064 nm.

    abstract::The optical properties (absorption and scattering coefficients and the scattering anisotropy factor) were measured in vitro for cartilage, liver, lung, muscle, myocardium, skin, and tumour (colon adenocarcinoma CC 531) at 630, 632.8, 790, 850 and 1064 nm. Rabbits, rats, piglets, goats, and dogs were used to obtain the...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/42/11/017

    authors: Beek JF,Blokland P,Posthumus P,Aalders M,Pickering JW,Sterenborg HJ,van Gemert MJ

    更新日期:1997-11-01 00:00:00

  • Evaluation of factors to convert absorbed dose calibrations from graphite to water for the NPL high-energy photon calibration service.

    abstract::The National Physical Laboratory (NPL) provides a high-energy photon calibration service using 4-19 MV x-rays and 60Co gamma-radiation for secondary standard dosemeters in terms of absorbed dose to water. The primary standard used for this service is a graphite calorimeter and so absorbed dose calibrations must be con...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/47/3/306

    authors: Nutbrown RF,Duane S,Shipley DR,Thomas RA

    更新日期:2002-02-07 00:00:00

  • Photothermal effects of laser tissue soldering.

    abstract::Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding techniqu...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/44/4/013

    authors: McNally KM,Sorg BS,Welch AJ,Dawes JM,Owen ER

    更新日期:1999-04-01 00:00:00

  • Dosimetric consequences of tumour motion due to respiration for a scanned proton beam.

    abstract::A method for simulating spot-scanned delivery to a moving tumour was developed which uses patient-specific image and plan data. The magnitude of interplay effects was investigated for two patient cases under different fractionation and respiratory motion variation scenarios. The use of volumetric rescanning for motion...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/56/20/003

    authors: Kraus KM,Heath E,Oelfke U

    更新日期:2011-10-21 00:00:00

  • Convex reformulation of biologically-based multi-criteria intensity-modulated radiation therapy optimization including fractionation effects.

    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

    pub_type: 杂志文章

    doi:10.1088/0031-9155/53/22/006

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

    更新日期:2008-11-21 00:00:00

  • The Hug-Kellerer equation as the universal cell survival curve.

    abstract::The Hug-Kellerer (H-K) equation is one of the earliest proposed radiation cell survival curves. We examine this equation in view of the recent perceived need for a universal cell survival curve which would be applicable to single radiation fractions at high doses. We derive relationships between the three parameters o...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/55/10/N01

    authors: Ekstrand KE

    更新日期:2010-05-21 00:00:00

  • Aerosol particle impaction in the conducting airways.

    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

    pub_type: 杂志文章

    doi:10.1088/0031-9155/29/7/001

    authors: Agnew JE,Pavia D,Clarke SW

    更新日期:1984-07-01 00:00:00

  • A method for energy window optimization for quantitative tasks that includes the effects of model-mismatch on bias: application to Y-90 bremsstrahlung SPECT imaging.

    abstract::Quantitative Yttrium-90 ((90)Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging has shown great potential to provide reliable estimates of (90)Y activity distribution for targeted radionuclide therapy dosimetry applications. One factor that potentially affects the reliability of the activity ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/57/12/3711

    authors: Rong X,Du Y,Frey EC

    更新日期:2012-06-21 00:00:00

  • Monte Carlo optimization of a microbeam collimator design for use on the small animal radiation research platform (SARRP).

    abstract::Microbeam radiation therapy (MRT) is a pre-clinical, spatially-fractionated treatment modality noted for its ability to achieve a large differential response between normal and tumoral tissues. In the present study, TOPAS Monte Carlo (MC) simulations were used to optimize the design of a compact, affordable multi-slit...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aad7e2

    authors: Esplen NM,Chergui L,Johnstone CD,Bazalova-Carter M

    更新日期:2018-08-29 00:00:00

  • Bulk optical properties of healthy female breast tissue.

    abstract::We have measured the bulk optical properties of healthy female breast tissues in vivo in the parallel plate, transmission geometry. Fifty-two volunteers were measured. Blood volume and blood oxygen saturation were derived from the optical property data using a novel method that employed a priori spectral information t...

    journal_title:Physics in medicine and biology

    pub_type: 临床试验,杂志文章

    doi:10.1088/0031-9155/47/16/302

    authors: Durduran T,Choe R,Culver JP,Zubkov L,Holboke MJ,Giammarco J,Chance B,Yodh AG

    更新日期:2002-08-21 00:00:00

  • Response, thermal regulatory threshold and thermal breakdown threshold of restrained RF-exposed mice at 905 MHz.

    abstract::The objective of this study was the determination of the thermal regulatory and the thermal breakdown thresholds for in-tube restrained B6C3F1 and NMRI mice exposed to radiofrequency electromagnetic fields at 905 MHz. Different levels of the whole-body averaged specific absorption rate (SAR = 0, 2, 5, 7.2, 10, 12.6 an...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/50/21/017

    authors: Ebert S,Eom SJ,Schuderer J,Apostel U,Tillmann T,Dasenbrock C,Kuster N

    更新日期:2005-11-07 00:00:00

  • Fast and exact Hessian computation for a class of nonlinear functions used in radiation therapy treatment planning.

    abstract::In nonlinear optimisation, using exact Hessian computations (full-Newton) hold superior convergence properties over quasi-Newton methods or gradient-based methods. However, for medium-scale problems, computing the Hessian can be computationally expensive and thus time-consuming. For solvers dedicated to a specific pro...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/ab1e17

    authors: van Haveren R,Breedveld S

    更新日期:2019-08-14 00:00:00

  • Significance of background optical properties, time-resolved information and optode arrangement in diffuse optical imaging of term neonates.

    abstract::The significance of accurate knowledge of background optical properties and time-resolved information in reconstructing images of hemodynamic changes in the neonatal brain from diffuse optical imaging data was studied using Monte Carlo (MC) simulation. A segmented anatomical magnetic resonance (MR) image and literatur...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/54/3/005

    authors: Heiskala J,Hiltunen P,Nissilä I

    更新日期:2009-02-07 00:00:00

  • An efficient strategy based on an individualized selection of registration methods. Application to the coregistration of MR and SPECT images in neuro-oncology.

    abstract::An efficient registration strategy is described that aims to help solve delicate medical imaging registration problems. It consists of running several registration methods for each dataset and selecting the best one for each specific dataset, according to an evaluation criterion. Finally, the quality of the registrati...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/59/22/6997

    authors: Tacchella JM,Roullot E,Lefort M,Cohen ME,Guillevin R,Petrirena G,Delattre JY,Habert MO,Yeni N,Kas A,Frouin F

    更新日期:2014-11-21 00:00:00

  • Mass-energy absorption coefficient and backscatter factor ratios for kilovoltage x-ray beams.

    abstract::For low-energy (up to 150 kV) x-rays, the ratio of mass-energy absorption coefficients for water to air, (mu(en)/rho)w.air, and the backscatter factor B are used in the conversion of air kerma, measured free-in-air, to water kerma on the surface of a water phantom. For clinical radiotherapy, similar conversion factors...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/44/1/011

    authors: Ma CM,Seuntjens JP

    更新日期:1999-01-01 00:00:00

  • Deformable and durable phantoms with controlled density of scatterers.

    abstract::We have developed deformable and durable optical tissue phantoms with a simple and well-defined microstructure including a novel combination of scatterers and a matrix material. These were developed for speckle and elastography investigations in optical coherence tomography, but should prove useful in many other field...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/53/13/N01

    authors: Bisaillon CE,Lamouche G,Maciejko R,Dufour M,Monchalin JP

    更新日期:2008-07-07 00:00:00

  • Lateral variations of radiobiological properties of therapeutic fields of 1H, 4He, 12C and 16O ions studied with Geant4 and microdosimetric kinetic model.

    abstract::As known, in cancer therapy with ion beams the relative biological effectiveness (RBE) of ions changes in the course of their propagation in tissues. Such changes are caused not only by increasing the linear energy transfer (LET) of beam particles with the penetration depth towards the Bragg peak, but also by nuclear ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aa75b2

    authors: Dewey S,Burigo L,Pshenichnov I,Mishustin I,Bleicher M

    更新日期:2017-06-27 00:00:00

  • Experimental characterization of lateral profiles of scanned proton and carbon ion pencil beams for improved beam models in ion therapy treatment planning.

    abstract::Scanned ion pencil beams carry a low-dose envelope which can extend up to several centimeters from the individual beam central axis. Depending on the energy and species of the beam, this halo consists mainly of secondary particles produced by nuclear interactions in the target or of particles undergoing multiple Coulo...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/56/24/009

    authors: Schwaab J,Brons S,Fieres J,Parodi K

    更新日期:2011-12-21 00:00:00

  • Late rectal bleeding after 3D-CRT for prostate cancer: development of a neural-network-based predictive model.

    abstract::The aim of this study was to develop a model exploiting artificial neural networks (ANNs) to correlate dosimetric and clinical variables with late rectal bleeding in prostate cancer patients undergoing radical radiotherapy and to compare the ANN results with those of a standard logistic regression (LR) analysis. 718 m...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/57/5/1399

    authors: Tomatis S,Rancati T,Fiorino C,Vavassori V,Fellin G,Cagna E,Mauro FA,Girelli G,Monti A,Baccolini M,Naldi G,Bianchi C,Menegotti L,Pasquino M,Stasi M,Valdagni R

    更新日期:2012-03-07 00:00:00

  • 2D convolution kernels of ionization chambers used for photon-beam dosimetry in magnetic fields: the advantage of small over large chamber dimensions.

    abstract::This study aims at developing an optimization strategy for photon-beam dosimetry in magnetic fields using ionization chambers. Similar to the familiar case in the absence of a magnetic field, detectors should be selected under the criterion that their measured 2D signal profiles M(x,y) approximate the absorbed dose to...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aab50c

    authors: Looe HK,Delfs B,Poppinga D,Harder D,Poppe B

    更新日期:2018-03-29 00:00:00

  • Estimating cancer risk from dental cone-beam CT exposures based on skin dosimetry.

    abstract::The aim of this study was to measure entrance skin doses on patients undergoing cone-beam computed tomography (CBCT) examinations, to establish conversion factors between skin and organ doses, and to estimate cancer risk from CBCT exposures. 266 patients (age 8-83) were included, involving three imaging centres. CBCT ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/59/14/3877

    authors: Pauwels R,Cockmartin L,Ivanauskaité D,Urbonienė A,Gavala S,Donta C,Tsiklakis K,Jacobs R,Bosmans H,Bogaerts R,Horner K,SEDENTEXCT Project Consortium.

    更新日期:2014-07-21 00:00:00

  • Single and multiple cross sections for ionizing processes of biological molecules by protons and alpha-particle impact: a classical Monte Carlo approach.

    abstract::A classical trajectory model has been used to predict total cross sections of single and double ionizing processes (including capture processes) for several ion-biological molecule collisional systems in the intermediate and high energy range. In this work, the systems studied are water, adenine or cytosine targets io...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/53/4/N03

    authors: Abbas I,Champion C,Zarour B,Lasri B,Hanssen J

    更新日期:2008-02-21 00:00:00

  • Optical-thermal characterization of cutaneous transilluminators.

    abstract::In recent years, there has been an increase in the popularity of light-emitting diode (LED)-based, battery-powered transilluminators (BPTs) for facilitating transdermal vascular access in adults and neonates. BPTs are believed to have lower potential for inducing skin burns than prior devices based on high-power broad...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/54/22/008

    authors: Pfefer TJ,Mehrabi A,James R,Landry R,Weininger S,Chang I,Kaufman D,Miller S

    更新日期:2009-11-21 00:00:00

  • Development of a GSO positron/single-photon imaging detector.

    abstract::We have developed and tested a GSO (gadolinium oxyorthosilicate) position-sensitive gamma detector which can be used with positron and single-photon radionuclides for imaging breast cancer or sentinel lymph node detection. Because GSO has a relatively good energy resolution for annihilation gammas as well as low energ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/51/2/018

    authors: Yamamoto S,Matsumoto K,Senda M

    更新日期:2006-01-21 00:00:00