Search results for " function interpolation."

showing 3 items of 3 documents

Fuzzy Smoothed Composition of Local Mapping Transformations for Non-rigid Image Registration

2009

This paper presents a novel method for medical image regis- tration. The global transformation is obtained by composing affine trans- formations, which are recovered locally from given landmarks. Transfor- mations of adjacent regions are smoothed to avoid blocking artifacts, so that a unique continuous and differentiable global function is obtained. Such composition is operated using a technique derived from fuzzy C- means clustering. The method was successfully tested on several datasets; results, both qualitative and quantitative, are shown. Comparisons with other methods are reported. Final considerations on the efficiency of the technique are explained.

Settore ING-INF/05 - Sistemi Di Elaborazione Delle Informazionibusiness.industryImage registrationPattern recognitionComposition (combinatorics)Blocking (statistics)Fuzzy logicfree form deformation image registration fuzzy clustering function interpolation.Global transformationComputer visionDifferentiable functionArtificial intelligenceAffine transformationbusinessCluster analysisMathematics
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Referenceless thermometry using radial basis function interpolation

2014

The Proton Resonance Frequency (PRF) shift provide a method for temperature change measurements during thermotherapy. Conventional PRF thermometry works subtracting one or multiple baseline images. The method leads to artifacts caused by tissue motion and frequency drift. Various works estimating the background phase from each acquired image phase are present in literature. These algorithms are called “referenceless” because they don’t require any subtraction of baseline images for calculating temperature increment. Conventional referenceless methods estimate baseline image by fitting the background phase outside the heated region through a polynomial approach. In this work a background pha…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniMaterials sciencebusiness.industryRadial basis function interpolationThermometry ultrasound thermal ablation referenceless methods RBF interpolation MRgFUSComputer visionArtificial intelligencebusinessComputational physics2014 World Symposium on Computer Applications & Research (WSCAR)
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Radial Basis Function Interpolation for Referenceless Thermometry Enhancement

2015

MRgFUS (Magnetic Resonance guided Focused UltraSound) is a new and non-invasive technique to treat different diseases in the oncology field, that uses Focused Ultrasound (FUS) to induce necrosis in the lesion. Temperature change measurements during ultrasound thermo-therapies can be performed through magnetic resonance monitoring by using Proton Resonance Frequency (PRF) thermometry. It measures the phase variation resulting from the temperature-dependent changes in resonance frequency by subtracting one phase baseline image from actual phase. Referenceless thermometry aims to re-duce artefacts caused by tissue motion and frequency drift, fitting the back-ground phase outside the heated reg…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniProton resonance frequencyMaterials sciencemedicine.diagnostic_testbusiness.industryFrequency driftUltrasoundPhase (waves)Magnetic resonance imagingRadial Basis Function Interpolation Referenceless Thermometry Artificial Neural Network MRgFUS.Radial basis function interpolationmedicineRadial basis functionbusinessBiomedical engineeringInterpolation
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