title: Improved measurement of vibration amplitude in dynamic optical coherence elastography.
abstract: Optical coherence elastography employs optical coherence tomography (OCT) to measure the displacement of tissues under load and, thus, maps the resulting strain into an image, known as an elastogram. We present a new improved method to measure vibration amplitude in dynamic optical coherence elastography. The tissue vibration amplitude caused by sinusoidal loading is measured from the spread of the Doppler spectrum, which is extracted using joint spectral and time domain signal processing. At low OCT signal-to-noise ratio (SNR), the method provides more accurate vibration amplitude measurements than the currently used phase-sensitive method. For measurements performed on a mirror at OCT SNR = 5 dB, our method introduces <3% error, compared to >20% using the phase-sensitive method. We present elastograms of a tissue-mimicking phantom and excised porcine tissue that demonstrate improvements, including a 50% increase in the depth range of reliable vibration amplitude measurement.
authors.affiliation: Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009,  Australia.
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Kennedy
authors.forename: Maciej
authors.initials: M
authors.lastname: Wojtkowski
authors.forename: Maciej
authors.initials: M
authors.lastname: Szkulmowski
authors.forename: Kelsey M
authors.initials: KM
authors.lastname: Kennedy
authors.forename: Karol
authors.initials: K
authors.lastname: Karnowski
authors.forename: David D
authors.initials: DD
authors.lastname: Sampson