Robust reconstruction of local optic axis orientation with fiber-based polarization-sensitive optical coherence tomography

Abstract

It is challenging to recover local optic axis orientation from samples probed with fiber-based polarization-sensitive optical coherence tomography (PS-OCT). In addition to the effect of preceding tissue layers, the transmission through fiber and system elements, and imperfect system alignment, need to be compensated. Here, we present a method to retrieve the required correction factors from measurements with depth-multiplexed PS-OCT, which accurately measures the full Jones matrix. The correction considers both retardation and diattenuation and is applied in the wavenumber domain, preserving the axial resolution of the system. The robustness of the method is validated by measuring a birefringence phantom with a misaligned system. Imaging ex-vivo lamb trachea and human bronchus demonstrates the utility of reconstructing the local optic axis orientation to assess smooth muscle, which is expected to be useful in the assessment of airway smooth muscle thickness in asthma, amongst other fiber-based applications.

Patient-specific targeted bronchial thermoplasty: predictions of improved outcomes with structure-guided treatment

“…An assumption of the study is that perfect information on airway structure is obtainable throughout the airway tree, which is currently impractical. Structural information can be obtained using CT (6), bronchoscopy (32), or OCT (1,22,25), but this is likely to be limited to a relatively small number of relatively large airways. Exactly how much data might be plausibly collected, and how much uncertainty this introduces into the structure-guided predictions, remains an open question.…”

Parametric imaging of attenuation by optical coherence tomography: review of models, methods, and clinical translation

“…123 Estimation of the birefringence and related polarization parameters (e.g., degree of polarization uniformity and optic axis orientation) represents an interesting alternative form of parametric imaging both with versions that integrate over similar axial regions as OCT attenuation imaging 72,132 and local versions. 133,134 Finally, retrieval of diattenuation-the polarization state-dependent differential attenuation-is also possible via PS-OCT but to the authors' knowledge is thought to be a small effect and has not yet been widely investigated. 135,136 Also based on polarization detection, Yashin et al 94 recently used crosspolarization OCT to simultaneously measure the attenuation coefficients of the co-and crosspolarized detected light.…”

Jones matrix‐based speckle‐decorrelation angiography using polarization‐sensitive optical coherence tomography

“…The measurement of the Jones matrix offers a pathway to extract additional tissue contrast associated with birefringence, such as phase retardation, birefringence and optic axis orientation. [19][20][21][22][23] By more complex processing, such measurements may also be converted to be differential with depth, either within a given large (ie, many resolution cells) window 24 or locally (ie, depth-resolved, to a single or a few resolution cells). 22,23 The complete detection of polarized signals in PS-OCT provides as a minimum a more reliable OCT signal, by eliminating polarization fading, which may improve OCTA imaging.…”