Design and realization of a hybrid medical imaging system: harmonic motion microwave doppler imaging

Download

index.pdf

Date

2016

Author

Tafreshi, Azadeh Kamali

Metadata

Show full item record

Item Usage Stats

263
views

325
downloads

Harmonic Motion Microwave Doppler Imaging (HMMDI) is a novel imaging modality to image electrical and mechanical properties of body tissues. This modality is recently proposed by the researchers in the METU EEE department for early-stage diagnosis of cancerous tissues. The main goal of this thesis study is to contribute various stages of the HMMDI's development processes. Speci cally, phantom development, dielectric and elastic characterization of the phantoms, experimental system realization, phantom experiments, and system performance evaluation, are in the scope of this thesis study. In the earlier stages, di effrent phantoms that mimic the mechanical and electrical properties of the body tissues are developed and characterized. In parallel to the phantom studies, experimental system design and realization studies are performed and the performance of the designed system is tested using phantom materials. The developed phantoms are scanned using the HMMDI method and the extracted information is used to generate HMMDI data profi les of the phantoms. The potential of detecting different tissues phantoms from the generated data pro files is explored. Eff ect of different vibration frequencies in HMMDI is discussed. In the acquired 2-D HMMDI data profi les, the potential of this imaging method in detecting 1) 5 mm tumor inside the fat, 2) 14 mm tumor phantom inside 25 mm fibro-glandular phantom in the middle of the fat phantom, 14 mm fi bro-glandular phantom inside the fat phantom, and 14 mm tumor inside the fat phantom, at the depth of 20 mm depths are observed. The experimental system limitations are clarif ed and the possible solutions to improve the system are presented.

Subject Keywords

Diagnostic imaging., Doppler ultrasonography., Diagnostic ultrasonic imaging., Breast, Microwave imaging in medicine.

URI

http://etd.lib.metu.edu.tr/upload/12619797/index.pdf
https://hdl.handle.net/11511/25478

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

An Improved Receiver for Harmonic Motion Microwave Doppler Imaging Soydan, Damla Alptekin; Irgin, Umit; Top, Can Baris; Gençer, Nevzat Güneri (2020-03-01) © 2020 EurAAP.Harmonic motion microwave Doppler imaging is a novel imaging modality that combines focused ultrasound and radar techniques to obtain data based on mechanical and electrical properties of the tissue. In previous experimental studies, the Doppler component of the scattered signal is sensed and used to create 2D images of a tumor inside a homogeneous fat phantom. Due to the drawbacks of the receiver configuration, scanning time was high, the signal-to-noise ratio was low, and the multi-frequency...
Analysis of reconstruction performance of magnetic resonance conductivity tensor imaging (MRCTI) using simulated measurements DEĞİRMENCİ, EVREN; Eyüboğlu, Behçet Murat (2017-01-01) Magnetic resonance conductivity tensor imaging (MRCTI) was proposed recently to produce electrical conductivity images of anisotropic tissues. Similar to magnetic resonance electrical impedance tomography (MREIT), MRCTI uses magnetic field and boundary potential measurements obtained utilizing magnetic resonance imaging techniques. MRCTI reconstructs tensor images of anisotropic conductivity whereas MREIT reconstructs isotropic conductivity images. In this study, spatial resolution and linearity of five rec...
Microwave Sensing of Acoustically Induced Local Harmonic Motion: Experimental and Simulation Studies on Breast Tumor Detection top, Can Baris; TAFRESHI, Azadeh Kamali; Gençer, Nevzat Güneri (2016-11-01) Sensing acoustically induced local harmonic motion using a microwave transceiver system may provide useful information for detecting nonpalpable tumors in dense breast tissue. For this purpose, we propose the harmonic motion microwave Doppler imaging method, in which the first harmonic of the phase modulated signal due to local harmonic motion is sensed. This signal is related to the dielectric, elastic, and acoustic properties of the vibrating region. The purpose of this paper is twofold: 1) to demonstrate...
Experimental studies for LFEIT with magnetic field measurements Tetik, Ahmet Önder; Gençer, Nevzat Güneri; Department of Electrical and Electronics Engineering (2018) Lorentz Force Electrical Impedance Tomography based on magnetic field measurements (LFEIT) is a hybrid imaging modality to image the electrical impedance of body tissues. In this modality, ultrasound pressure waves applied to the body tissues under static magnetic fields induce Lorentz currents. Magnetic flux density due to these currents is measured using receiver coils. The main aim of this thesis is to develop an experimental setup and a data acquisition system to obtain LFEIT sig nals from phantoms. Mor...
Received Signal in Harmonic Motion Microwave Doppler Imaging as a Function of Tumor Position in a 3D Scheme IRGIN, Umit; TOP, Can Baris; TAFRESHI, Azadeh Kamali; Gençer, Nevzat Güneri (2017-02-08) Harmonic Motion Microwave Doppler Imaging method, which was proposed as an alternative method for breast tumor detection, is a combination of microwave radar and focused ultrasound techniques yielding data depending on electrical and mechanical properties of the tissue. In this study, Harmonic Motion Microwave Doppler Imaging data from a small tumor inside homogeneous fat is analyzed as a function of tumor location on three orthogonal planes using Finite Difference Time Domain simulations. The results show ...

Citation Formats

A. K. Tafreshi, “Design and realization of a hybrid medical imaging system: harmonic motion microwave doppler imaging,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.