Large blood vessel effect on thermal ablation with a water-cooled microwave antenna

2010 ◽  
Author(s):  
Qun Nan ◽  
Yulin Lu ◽  
Youjun Liu ◽  
Yi Zeng
Keyword(s):  
Blood Vessel ◽  
Thermal Ablation ◽  
Microwave Antenna ◽  
Large Blood Vessel

The Comparison of Two Simulation Methods on the Thermal Ablation with Large Blood Vessel

2013 ◽  
Vol 444-445 ◽  
pp. 1177-1181
Author(s):  
Fei Zhai ◽  
Qun Nan ◽  
Hui Juan Zhang ◽  
Xue Mei Guo
Keyword(s):  
Heat Exchange ◽  
Blood Vessel ◽  
Thermal Ablation ◽  
Blood Flow Rate ◽  
Bioheat Transfer ◽  
Microwave Antenna ◽  
Simulation Methods ◽  
Large Blood Vessel ◽  
Significant Difference ◽  
Coupling Algorithm

Purpose: The aim of this study is to contrast the coupling algorithm (CEE) and boundary heat exchange coefficients (Nu) used in treatment of the large blood vessel in thermal ablation. Methods: Based on the Pennes bioheat transfer equation, the models with blood vessel parallel to microwave antenna were built with finite element method. In two kind of simulation, blood flow rate was set in 0.2 m/s or boundary heat exchange coefficients was set in 1750 W / (m2 °C), respectively. Results and conclusions : There was no significant difference on shape of effective ablation areas and 54°C temperature contours by using two kinds of simulation methods, especially the place far away from the blood vessel. At the place near the blood vessel, the method of CEE is closer to real condition which considers directivity of blood. Whats more, there are higher temperature by using method of Nu inside effective ablation areas.

Mathematical Modeling of Thermal Ablation in Tissue Surrounding a Large Vessel

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Xin Chen ◽  
Gerald M. Saidel
Keyword(s):  
Temperature Distribution ◽  
Blood Vessel ◽  
Thermal Ablation ◽  
Large Vessel ◽  
Tissue Temperature ◽  
Maximum Temperature ◽  
Capillary Perfusion ◽  
Distribution Dynamics ◽  
Large Blood Vessel ◽  
Power Inputs

Thermal ablation of a solid tumor in a tissue with radio-frequency (rf) energy can be accomplished by using a probe inserted into the tissue under the guidance of magnetic resonance imaging. The extent of the ablation can be significantly reduced by heat loss from capillary perfusion and by blood flow in a large vessel in the tissue. A mathematical model is presented of the thermal processes that occur during rf ablation of a tissue near a large blood vessel, which should not be damaged. Temperature distribution dynamics are described by the combination of a 3D bioheat transport in tissue together with a 1D model of convective-dispersive heat transport in the blood vessel. The objective was to determine how much of the tissue can be ablated without damaging the blood vessel. This was achieved by simulating the tissue temperature distribution dynamics and by determining the optimal power inputs so that a maximum temperature increase in the tissue was achieved without inducing tissue damage at the edge of the large vessel. The main contribution of this study is to provide a model analysis for pretreatment and, eventually, for intra-operative application to thermal ablation of a tumor located near a large blood vessel.

Proceso de Optimización y Evaluación de una Antena Micro-coaxial para el Tratamiento de Tumores Óseos

2021 ◽  
Author(s):  
◽  
S. E. Rojas Hernández
Keyword(s):  
Quality Of Life ◽  
Radiation Therapy ◽  
Thermal Ablation ◽  
Bone Tumors ◽  
Tumor Volume ◽  
Microwave Antenna ◽  
Comsol Multiphysics ◽  
Necrotic Tissue ◽  
The One

Bone tumors are commonly treated with surgery (amputation), radiation therapy, and chemotherapy; however, its side effects compromise the patient’ quality of life. Thermotherapy is a less aggressive alternative to treat these tumors. In thermal ablation temperatures between 60 °C-100 °C must be reached in the tumor. The process to design and optimize a one-slot microwave antenna by using COMSOL Multiphysics, is proposed. An axi-symmetric 2D parametric study was carried out, in which 576 scenarios (antenna designs) were analyzed to choose the one that allowed higher energy transmission, temperature increases in the ablation range, larger areas of necrotic tissue, etc. From this study, the best scenario was chosen to evaluate its performance by using a 3D anatomical model. The final optimized antenna presented a SWR = 1.45; moreover, it was possible to observed that the 67.35% of tumor volume reaches ablation temperatures.

scholarly journals Pre-Diabetes Induces Ultrastructural Alterations in the Large Blood Vessel Aorta in Rats

2019 ◽  
Vol 37 (2) ◽  
pp. 647-653
Author(s):  
Abbas O El-Karib ◽  
Mohammad Dallak ◽  
Mohamed Abd-Ellatif ◽  
Refaat A Eid ◽  
Mohamed A Haidara ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Ultrastructural Alterations ◽  
Large Blood Vessel

scholarly journals Interleukin-10 induces E-selectin on small and large blood vessel endothelial cells.

1996 ◽  
Vol 184 (3) ◽  
pp. 821-829 ◽  
Author(s):  
M Vora ◽  
L I Romero ◽  
M A Karasek
Keyword(s):  
Endothelial Cells ◽  
Blood Vessel ◽  
Skin Diseases ◽  
Umbilical Vein ◽  
Quantitative Polymerase Chain Reaction ◽  
Pcr Analysis ◽  
Transcriptional Level ◽  
Neutrophil Accumulation ◽  
Inflammatory Skin Diseases ◽  
Large Blood Vessel

In vitro, expression of E-selectin is largely restricted to endothelial cells activated by inflammatory cytokines. Under activated conditions, cytokines such as interleukin (IL) 10, released by keratinocytes in large quantities, may also increase the expression of E-selectin on the dermal microvasculature. The aim of the present study was to investigate the expression of E-selectin on cultured human dermal microvascular endothelial cells (HDMEC) isolated from neonatal foreskins when exposed to IL-10. Expression of E-selectin was determined by immunofluorescence microscopy, FACS analysis, an HL-60 cell-binding assay, and quantitative polymerase chain reaction (PCR) analysis. For comparison with large blood vessel cells, the expression of E-selectin on human umbilical vein endothelial cells (HUVEC) was also determined in parallel by FACS and reverse transcriptase-PCR analysis under identical conditions. These studies demonstrate that IL-10 induces the expression of E-selectin on both HDMEC and HUVEC and that the level of expression of HDMEC is comparable with that induced by IL-1 beta and tumor necrosis factor-alpha. When HL-60 cells are incubated with HDMEC pretreated with IL-10, a consistent increase in adherence of HL-60 to endothelial cells is observed. This adherence was found to be mediated by L-selectin. PCR analysis and the quantification of E-selectin cDNA by a novel, highly sensitive and specific PCR-immunoassay demonstrate the induction of E-selectin mRNA at the transcriptional level. The induction of the expression of E-selectin by IL-10 on HDMEC may provide additional insights into the pathogenic mechanism of neutrophil accumulation at the site of inflammation in inflammatory skin diseases.

Large blood vessel cooling in heated tissues: a numerical study

1995 ◽  
Vol 40 (4) ◽  
pp. 477-494 ◽  
Author(s):  
M C Kolios ◽  
M D Sherar ◽  
J W Hunt
Keyword(s):  
Blood Vessel ◽  
Numerical Study ◽  
Large Blood Vessel

Investigation Into the Acoustic Streaming and Convective Cooling Phenomena During a High-Intensity Focused Ultrasound Thermal Ablation

2011 ◽  
Author(s):  
Maxim A. Solovchuk ◽  
Tony W. H. Sheu ◽  
Marc Thiriet
Keyword(s):  
Blood Vessel ◽  
High Intensity ◽  
Thermal Ablation ◽  
Focused Ultrasound ◽  
Acoustic Streaming ◽  
Flow Distribution ◽  
Tissue Perfusion ◽  
High Intensity Focused Ultrasound ◽  
Hepatic Tissue ◽  
Convective Cooling

The present study is aimed at predicting liver tumor temperature increase during a high-intensity focused ultrasound (HIFU) thermal ablation using the proposed acoustics-heat-fluid coupling model. The linear Westervelt equation is adopted for modeling the incident finite-amplitude wave propagation. The nonlinear hemodynamic equations are also taken into account in the simulation domain that contains a hepatic tissue domain, where homogenization dominates perfusion, and a vascular domain, where blood convective cooling may be essential in determining the success of HIFU. We also consider the energy equation for the modeling thermal conduction heat transfer. Two heat sinks are dealt with to account for tissue perfusion and forced convection-induced cooling. The effect of acoustic streaming is also included in the current HIFU simulation study. Convective cooling in large blood vessel and acoustic streaming were shown to change the temperature near blood vessel. It was shown that the acoustic streaming effect can change the blood flow distribution in hepatic arterial branches and leads to mass flux redistribution. The effect of acoustic streaming can be used to control blood drug delivery. In the current work the realistic geometry for the blood vessel and liver was reconstructed using the MRI images. The presented results may be further used to construct a surgical planning platform for the non-invasive HIFU (High-Intensity Focal Ultrasound) tumor ablating (or cauterizing) therapy in real liver geometry on the basis of the MRI image.

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