Carbon dioxide reactivity of computed tomography functional parameters in rabbit VX2 soft tissue tumour.

Abstract:

:Tumour blood flow is one of the important factors limiting the efficacy of radiation therapy (hypoxic radioresistance), chemotherapy (drug delivery) and thermal therapy (heat dissipation) in treating cancer. The modification of tumour blood flow has been an area of intense investigation. In the current study, the arterial carbon dioxide tension (PaCO2) was changed in order to investigate the tumour vascular response to carbon dioxide. Functional maps of blood flow, blood volume and mean transit time were generated at four PaCO2 levels in VX2 tumour in the rabbit thigh and normal soft tissue. The PaCO2 levels investigated were normocapnia (PaCO2 = 40.9 +/- 1.2 mmHg), hypocapnia (27.2 +/- 2.3 and 33.5 +/- 2.3 mmHg) and hypercapnia (54.9 +/- 4.4 mmHg). The carbon dioxide reactivity of the global tumour blood flow and mean transit time showed significant differences between normocapnia and the two levels of hypocapnia, but not between normocapnia and hypercapnia. The average fractional change of blood flow from normocapnia for the two levels of hypocapnia was -0.41 +/- 0.06 and -0.29 +/- 0.08, respectively (P < 0.05). In the case of mean transit time the fractional change was +0.39 +/- 0.30 and +0.23 +/- 0.24, respectively (P < 0.05). The fractional change of blood volume from normocapnia, however, was not significantly different at any capnic level, as was the case with respect to each of the functional parameters in normal tissue. The ability to reduce blood flow and increase mean transit time through hypocapnia has significant implications in thermal therapy, since heat dissipation is a major factor in limiting the effectiveness of treatment.

journal_name

Phys Med Biol

authors

Purdie TG,Lee TY

doi

10.1088/0031-9155/48/7/303

subject

Has Abstract

pub_date

2003-04-07 00:00:00

pages

849-60

issue

7

eissn

0031-9155

issn

1361-6560

journal_volume

48

pub_type

杂志文章
  • Development of a synthetic single crystal diamond dosimeter for dose measurement of clinical proton beams.

    abstract::The scope of this work was to develop a synthetic single crystal diamond dosimeter (SCDD-Pro) for accurate relative dose measurements of clinical proton beams in water. Monte Carlo simulations were carried out based on the MCNPX code in order to investigate and reduce the dose curve perturbation caused by the SCDD-Pro...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aa70cf

    authors: Moignier C,Tromson D,de Marzi L,Marsolat F,García Hernández JC,Agelou M,Pomorski M,Woo R,Bourbotte JM,Moignau F,Lazaro D,Mazal A

    更新日期:2017-07-07 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

  • MR-guided transcranial brain HIFU in small animal models.

    abstract::Recent studies have demonstrated the feasibility of transcranial high-intensity focused ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes provision of accurate targeting, monitoring and control of this emerging therapeutic modality in order to ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/55/2/003

    authors: Larrat B,Pernot M,Aubry JF,Dervishi E,Sinkus R,Seilhean D,Marie Y,Boch AL,Fink M,Tanter M

    更新日期:2010-01-21 00:00:00

  • High-resolution fluence verification for treatment plan specific QA in ion beam radiotherapy.

    abstract::Ion beam radiotherapy exploits the finite range of ion beams and the increased dose deposition of ions toward the end of their range in material. This results in high dose conformation to the target region, which can be further increased using scanning ion beams. The standard method for patient-plan verification in io...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/58/6/1725

    authors: Martišíková M,Brons S,Hesse BM,Jäkel O

    更新日期:2013-03-21 00:00:00

  • The IPEM code of practice for determination of the reference air kerma rate for HDR (192)Ir brachytherapy sources based on the NPL air kerma standard.

    abstract::This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR (192)Ir brachytherapy sources. I...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/55/11/011

    authors: Bidmead AM,Sander T,Locks SM,Lee CD,Aird EG,Nutbrown RF,Flynn A,IPEM Working Party.

    更新日期:2010-06-07 00:00:00

  • Prediction of lung tumor motion using nonlinear autoregressive model with exogenous input.

    abstract::The present note addresses the development of a lung tumor position predictor to be used in dynamic tumor tracking radiotherapy, abbreviated as DTT-RT. As there exists 50-500 ms positioning lag in the control of the multi-leaf collimator (MLC) of commercial medical linear accelerators, prediction of future lung tumor ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/ab49ea

    authors: Jiang K,Fujii F,Shiinoki T

    更新日期:2019-10-31 00:00:00

  • Exact reconstruction in 2D dynamic CT: compensation of time-dependent affine deformations.

    abstract::This work is dedicated to the reduction of reconstruction artefacts due to motion occurring during the acquisition of computerized tomographic projections. This problem has to be solved when imaging moving organs such as the lungs or the heart. The proposed method belongs to the class of motion compensation algorithms...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/49/11/004

    authors: Roux S,Desbat L,Koenig A,Grangeat P

    更新日期:2004-06-07 00:00:00

  • Iterative image-domain ring artifact removal in cone-beam CT.

    abstract::Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aa7017

    authors: Liang X,Zhang Z,Niu T,Yu S,Wu S,Li Z,Zhang H,Xie Y

    更新日期:2017-07-07 00:00:00

  • A comprehensive study of the use of temporal moments in time-resolved diffuse optical tomography: part I. Theoretical material.

    abstract::The problem of fluorescence diffuse optical tomography consists in localizing fluorescent markers from near-infrared light measurements. Among the different available acquisition modalities, the time-resolved modality is expected to provide measurements of richer information content. To extract this information, the m...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/54/23/004

    authors: Ducros N,Hervé L,Da Silva A,Dinten JM,Peyrin F

    更新日期:2009-12-07 00:00:00

  • In vivo dosimetry in the urethra using alanine/ESR during (192)Ir HDR brachytherapy of prostate cancer--a phantom study.

    abstract::A phantom study for dosimetry in the urethra using alanine/ESR during (192)Ir HDR brachytherapy of prostate cancer is presented. The measurement method of the secondary standard of the Physikalisch-Technische Bundesanstalt had to be slightly modified in order to be able to measure inside a Foley catheter. The absorbed...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/54/9/022

    authors: Anton M,Wagner D,Selbach HJ,Hackel T,Hermann RM,Hess CF,Vorwerk H

    更新日期:2009-05-07 00:00:00

  • Intermittent cryogen spray cooling for optimal heat extraction during dermatologic laser treatment.

    abstract::Fast heat extraction is critically important to obtain the maximal benefit of cryogen spray cooling (CSC) during laser therapy of shallow skin lesions, such as port wine stain birthmarks. However, a film of liquid cryogen can build up on the skin surface, impairing heat transfer due to the relatively low thermal condu...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/47/18/301

    authors: Majaron B,Svaasand LO,Aguilar G,Nelson JS

    更新日期:2002-09-21 00:00:00

  • Wavelet compression in medical terahertz pulsed imaging.

    abstract::This paper concerns the robustness of discrete wavelet transform (DWT) compression in terahertz pulsed imaging (TPI). TPI datasets consist of terahertz time-domain series which are sampled at each 'pixel' of the image, leading to file sizes which are typically of the order of several megabytes (MB) per image. This mak...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/47/21/328

    authors: Handley JW,Fitzgerald AJ,Berry E,Boyle RD

    更新日期:2002-11-07 00:00:00

  • The validation of tomotherapy dose calculations in low-density lung media.

    abstract::The dose-calculation accuracy of the tomotherapy Hi-Art II(R) (Tomotherapy, Inc., Madison, WI) treatment planning system (TPS) in the presence of low-density lung media was investigated. In this evaluation, a custom-designed heterogeneous phantom mimicking the mediastinum geometry was used. Gammex LN300 and balsa wood...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/54/8/004

    authors: Chaudhari SR,Pechenaya OL,Goddu SM,Mutic S,Rangaraj D,Bradley JD,Low D

    更新日期:2009-04-21 00:00:00

  • Visually interpretable deep network for diagnosis of breast masses on mammograms.

    abstract::Recently, deep learning technology has achieved various successes in medical image analysis studies including computer-aided diagnosis (CADx). However, current CADx approaches based on deep learning have a limitation in interpreting diagnostic decisions. The limited interpretability is a major challenge for practical ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aaef0a

    authors: Kim ST,Lee JH,Lee H,Ro YM

    更新日期:2018-12-04 00:00:00

  • Intraventricular vector flow mapping-a Doppler-based regularized problem with automatic model selection.

    abstract::We propose a regularized least-squares method for reconstructing 2D velocity vector fields within the left ventricular cavity from single-view color Doppler echocardiographic images. Vector flow mapping is formulated as a quadratic optimization problem based on an [Formula: see text]-norm minimization of a cost functi...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aa7fe7

    authors: Assi KC,Gay E,Chnafa C,Mendez S,Nicoud F,Abascal JFPJ,Lantelme P,Tournoux F,Garcia D

    更新日期:2017-08-11 00:00:00

  • Role of skin tissue layers and ultra-structure in transcutaneous electrical stimulation including tDCS.

    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

    pub_type: 杂志文章

    doi:10.1088/1361-6560/abb7c1

    authors: Khadka N,Bikson M

    更新日期:2020-09-11 00:00:00

  • Optimizing functional parameter accuracy for breath-hold DCE-MRI of liver tumours.

    abstract::Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a valuable tool for assessing treatment response to novel cancer therapeutics. With appropriate data acquisition, quantitative functional parameter estimates can be obtained by fitting a model to the data. This research focuses on applying a dual-input ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/54/7/023

    authors: Orton MR,Miyazaki K,Koh DM,Collins DJ,Hawkes DJ,Atkinson D,Leach MO

    更新日期:2009-04-07 00:00:00

  • A comparison between the patella and the calcaneus using ultrasound velocity and attenuation as predictors of bone mineral density.

    abstract::The bone mineral density (BMD), ultrasound velocity (UV) and attenuation were examined in sixteen matched sets of human patellae and calcanei. For the sixteen calcanei, BMD was strongly correlated with all ultrasound parameters. Calcaneal UV appeared to be inferior to attenuation in the ability to predict BMD. For the...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/42/10/008

    authors: Han SM,Davis J

    更新日期:1997-10-01 00:00:00

  • Design and performance of the micro-dose calibrator.

    abstract::A new class of dose calibrator called a micro-dose calibrator, designed to measure radioactivity rates in the range between 1 kBq up to 370 kBq, has been designed and an 8 NaI(Tl)/photo multiplier tube (PMT) module prototype built to evaluate its performance. The design of the micro-dose calibrator is based on the con...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aadb3b

    authors: Adler S,Choyke P

    更新日期:2018-09-10 00:00:00

  • Volumetric characterization of the Aurora magnetic tracker system for image-guided transorbital endoscopic procedures.

    abstract::In some medical procedures, it is difficult or impossible to maintain a line of sight for a guidance system. For such applications, people have begun to use electromagnetic trackers. Before a localizer can be effectively used for an image-guided procedure, a characterization of the localizer is required. The purpose o...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/53/16/009

    authors: Atuegwu NC,Galloway RL

    更新日期:2008-08-21 00:00:00

  • Factors affecting the repeatability of gamma camera calibration for quantitative imaging applications using a sealed source.

    abstract::Several applications in nuclear medicine require absolute activity quantification of single photon emission computed tomography images. Obtaining a repeatable calibration factor that converts voxel values to activity units is essential for these applications. Because source preparation and measurement of the source ac...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/60/3/1325

    authors: Anizan N,Wang H,Zhou XC,Wahl RL,Frey EC

    更新日期:2015-02-07 00:00:00

  • Controlled E-field gradient coils for MRI.

    abstract::Peripheral neural stimulation is a major problem in current gradient coil designs. Induced current problems in patients relate directly to gradient strength and modulation frequency. Present designs of gradient coil tend to limit ultra-high-speed imaging methods such as echo-planar imaging (EPI) and echo-volumar imagi...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/53/7/001

    authors: Mansfield P,Haywood B

    更新日期:2008-04-07 00:00:00

  • New compensator design options for charged-particle radiotherapy.

    abstract::The purpose of this investigation is to propose new compensator design strategies for protons and heavier particles which are based on pencil-beam (PB) dose calculations and which significantly reduce the dose to tissues downstream from the target, yet provide acceptable target coverage under conditions of patient mot...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/42/7/005

    authors: Petti PL

    更新日期:1997-07-01 00:00:00

  • How to harmonize SUVs obtained by hybrid PET/CT scanners with and without point spread function correction.

    abstract::State of the art point-spread function (PSF) corrections implemented in positron emission tomography/computed tomography (PET/CT) reconstruction improved image quality and diagnostic performance but caused an increase in the standardized uptake value (SUV) compared to a conventional OSEM reconstruction system. The EAN...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aaee27

    authors: Ferretti A,Chondrogiannis S,Rampin L,Bellan E,Marzola MC,Grassetto G,Gusella S,Maffione AM,Gava M,Rubello D

    更新日期:2018-11-26 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

  • Kill painting of hypoxic tumors with multiple ion beams.

    abstract::We report on a novel method for simultaneous biological optimization of treatment plans for hypoxic tumors using multiple ion species. Our previously introduced kill painting approach, where the overall cell killing is optimized on biologically heterogeneous targets, was expanded with the capability of handling differ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aafe40

    authors: Sokol O,Krämer M,Hild S,Durante M,Scifoni E

    更新日期:2019-02-08 00:00:00

  • SiPM signal readout for inter-crystal scatter event identification in PET detectors.

    abstract::In positron emission tomography (PET) with pixelated detectors, a significant number of annihilation photons interact with scintillation crystals through single or multiple Compton scattering events. When these partial energy depositions occur across multiple crystal elements, we call them inter-crystal scatter (ICS) ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/aba8b4

    authors: Park H,Lee JS

    更新日期:2020-10-21 00:00:00

  • Comparing the effectiveness and efficiency of various gating approaches for PBS proton therapy of pancreatic cancer using 4D-MRI datasets.

    abstract::Abdominal organ motion may lead to considerable uncertainties in pencil-beam scanning (PBS) proton therapy of pancreatic cancer. Beam gating, where irradiation only occurs in certain breathing phases in which the gating conditions are fulfilled, may be an option to reduce the interplay effect between tumor motion and ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/1361-6560/ab1175

    authors: Dolde K,Naumann P,Dávid C,Kachelriess M,Lomax AJ,Weber DC,Saito N,Burigo LN,Pfaffenberger A,Zhang Y

    更新日期:2019-04-10 00:00:00

  • Dose effect of guidewire position in intravascular brachytherapy.

    abstract::It has been reported that the dose effects of metallic guidewires are significant in intravascular brachytherapy (IVBT) using a beta source. The purpose of this work is to investigate the dependence of these dose effects on guidewire position. The EGS4 Monte Carlo codes were used to perform the dose calculations for t...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/47/10/309

    authors: Shih R,Hsu WL,Li XA

    更新日期:2002-05-21 00:00:00

  • Multi-view 3D echocardiography compounding based on feature consistency.

    abstract::Echocardiography (echo) is a widely available method to obtain images of the heart; however, echo can suffer due to the presence of artefacts, high noise and a restricted field of view. One method to overcome these limitations is to use multiple images, using the 'best' parts from each image to produce a higher qualit...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章

    doi:10.1088/0031-9155/56/18/020

    authors: Yao C,Simpson JM,Schaeffter T,Penney GP

    更新日期:2011-09-21 00:00:00