Show simple item record

dc.contributor.advisorWang, Lihong V.
dc.creatorKu, Geng
dc.date.accessioned2006-04-12T16:04:00Z
dc.date.available2006-04-12T16:04:00Z
dc.date.created2004-12
dc.date.issued2006-04-12
dc.identifier.urihttp://hdl.handle.net/1969.1/3181
dc.description.abstractPhotoacoustic tomography (PAT), as well as thermoacoustic tomography (TAT), utilize electromagnetic radiation in its visible, near infrared, microwave, and radiofrequency forms, respectively, to induce acoustic waves in biological tissues for imaging purposes. Combining the advantages of both the high image contrast that results from electromagnetic absorption and the high resolution of ultrasound imaging, these new imaging modalities could be the next successful imaging techniques in biomedical applications. Basic research on PAT and TAT, and the relevant physics, is presented in Chapter I. In Chapter II, we investigate the imaging mechanisms of TAT in terms of signal generation, propagation and detection. We present a theoretical analysis as well as simulations of such imaging characteristics as contrast and resolution, accompanied by experimental results from phantom and tissue samples. In Chapter III, we discuss the further application of TAT to the imaging of biological tissues. The microwave absorption difference in normal and cancerous breast tissues, as well as its influence on thermoacoustic wave generation and the resulting transducer response, is investigated over a wide range of electromagnetic frequencies and depths of tumor locations. In Chapter IV, we describe the mechanism of PAT and the algorithm used for image reconstruction. Because of the broad bandwidth of the laser-induced ultrasonic waves and the limited bandwidth of the single transducer, multiple ultrasonic transducers, each with a different central frequency, are employed for simultaneous detection. Chapter V further demonstrates PAT’s ability to image vascular structures in biological tissue based on blood’s strong light absorption capability. The photoacoustic images of rat brain tumors in this study clearly reveal the angiogenesis that is associated with tumors. In Chapter VI, we report on further developing PAT to image deeply embedded optical heterogeneity in biological tissues. The improved imaging ability is attributed to better penetration by NIR light, the use of the optical contrast agent ICG (indocyanine green) and a new detection scheme of a circular scanning configuration. Deep penetrating PAT, which is based on a tissue’s intrinsic contrast using laser light of 532 nm green light and 1.06 µm near infrared light, is also presented.en
dc.format.extent3052679 bytesen
dc.format.mediumelectronicen
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherTexas A&M University
dc.subjectphotoacoustic tomographyen
dc.subjectthermoacoustic tomographyen
dc.subjectmicrowaveen
dc.subjectultrasonicsen
dc.subjectmedical imagingen
dc.subjectbiological tissueen
dc.subjectbrain imagingen
dc.subjectspatial resolutionen
dc.subjectreconstructionen
dc.subjectpenetration depthen
dc.subjectabsorption coefficienten
dc.subjectcontrast agenten
dc.titlePhotoacoustic and thermoacoustic tomography: system development for biomedical applicationsen
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentBiomedical Engineeringen
thesis.degree.disciplineBiomedical Engineeringen
thesis.degree.grantorTexas A&M Universityen
thesis.degree.nameDoctor of Philosophyen
thesis.degree.levelDoctoralen
dc.contributor.committeeMemberStoica, Georghe
dc.contributor.committeeMemberCote, Gerard L.
dc.contributor.committeeMemberWu, Hsin-i
dc.type.genreElectronic Dissertationen
dc.type.materialtexten
dc.format.digitalOriginborn digitalen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record