Magnetomotive optical coherence tomography and elastography with applications in magnetic thermotherapy dosimetry

Huang, Pin-Chieh

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https://hdl.handle.net/2142/109607 Copy

Description

Title

Magnetomotive optical coherence tomography and elastography with applications in magnetic thermotherapy dosimetry

Author(s)

Huang, Pin-Chieh

Issue Date

2020-12-02

Director of Research (if dissertation) or Advisor (if thesis)

Boppart, Stephen A

Doctoral Committee Chair(s)

Boppart, Stephen A

Committee Member(s)

• Insana, Michael F
• Sutton, Bradley P
• Sobh, Nahil A

Department of Study

Bioengineering

Discipline

Bioengineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Optical coherence tomography
• Elastography
• Magnetic nanoparticles
• Magnetic hyperthermia

Abstract

Magnetic nanoparticles (MNPs), with their versatility, have raised extensive interest in the field of biomedicine. MNPs can be delivered to the tumors as therapeutic agents in magnetic thermotherapy (MT) to ablate the malignancies. Remotely manipulated with an external magnetic field, the same MNPs can also induce “magnetomotions”, which can be detected via magnetomotive optical coherence tomography (MM-OCT) and enable biomechanical characterization with magnetomotive optical coherence elastography (MM-OCE). In this thesis, the theranostic functionality of MNPs are exploited, where the biomechanical alterations of the MT-treated tissues were probed by MM-OCE; thereby providing a biophysically informative evaluation of the thermal damage. Treated with MNP hyperthermia, the elasticity changes were qualitatively measured based on the natural/resonant frequency detected by transient-response or spectroscopic MM-OCE. Interstitial MT was provided using a magnetic thermoseed, and the thermally perturbed tissue stiffness was quantified with shear-wave MM-OCE. From ex vivo porcine livers, a linear correlation between the stiffness increase and the thermal energy deposited was observed, offering physical meanings to the elasticity-based metric. In addition, in vivo MM-OCE-based elastograms were generated, for the first time, with an accelerated MM-OCE platform developed with a single chirped force excitation, rapid BM-mode scanning, and parallel-programming-based image reconstruction. Finally, the association between the tissue elasticity, the fundamental biological variations (i.e. tumor cellularity, protein conformation forms), and the MT-induced temperature rise was characterized on in vivo murine melanoma tumors. It was observed that tumors with lower cellularity can be softened after MT treatment. In contrast, depending on the temperature rise achieved and the conformation forms of the collagen fibers, highly cellular tumors can be stiffened either reversibly or irreversibly. In summary, theranostic MNPs can be delivered to the tumors and tracked by MM-OCT imaging. The MT-induced biomechanical alteration (which is related to the intrinsic biological features and molecular changes) can then also be characterized with MM-OCE.

Graduation Semester

2020-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/109607

Copyright and License Information

Copyright 2020 Pin-Chieh Huang

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