Imaging elastographic contrast in optical coherence tomography for applications in dermatology and oncology
2012
Skin cancer diagnosis often requires invasive biopsies. These can be time-consuming
and cause discomfort to the patient. Optical coherence tomography is a non-invasive
tool capable of imaging skin on the micron scale. However, the modality’s contrast
sensitivity limits its ability to distinguish between healthy and diseased tissue in
some non-melanoma skin cancers. In this thesis, optical coherence elastography is
explored as a means of contrast enhancement through the analysis of a sample’s
mechanical, rather than optical, properties.
An analysis of OCT imaging performance is used to design a suitable elastography
phantom. Experimental measurements are also used to optimise the image
tracking software. A well-defined, controlled actuation is applied to a tissue phantom
and imaged using optical coherence elastography. A stiff inclusion is subsequently
discerned from the surrounding material, even though conventional image contrast
is low. Elastographic detail is also depicted in tissue. Finally, enhancements in axial
displacement sensitivity are acquired through the acquisition of phase data and
alternative actuation techniques are explored.
The optical coherence elastography technique was sensitive to a Young’s modulus
ratio of 7 from a 56 μm actuation. The possibility of detecting smaller changes
in mechanical properties was also investigated. Axial phase displacement sensitivity
was 50 nm, with an order of magnitude increase in strain sensitivity. This demonstrates
the technique’s potential usefulness in discriminating between cancerous and
healthy tissues.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
1
Citations
NaN
KQI