title: Extracting structural features of rat sciatic nerve using polarization-sensitive spectral domain optical coherence tomography.
abstract: We present spectral domain polarization-sensitive optical coherence tomography (SD PS-OCT) imaging of peripheral nerves. Structural and polarization-sensitive OCT imaging of uninjured rat sciatic nerves was evaluated both qualitatively and quantitatively. OCT and its functional extension, PS-OCT, were used to image sciatic nerve structure with clear delineation of the nerve boundaries to muscle and adipose tissues. A long-known optical effect, bands of Fontana, was also observed. Postprocessing analysis of these images provided significant quantitative information, such as epineurium thickness, estimates of extinction coefficient and birefringence of nerve and muscle tissue, frequency of bands of Fontana at different stretch levels of nerve, and change in average birefringence of nerve under stretched condition. We demonstrate that PS-OCT combined with regular-intensity OCT (compared with OCT alone) allows for a clearer determination of the inner and outer boundaries of the epineurium and distinction of nerve and muscle based on their birefringence pattern. PS-OCT measurements on normal nerves show that the technique is promising for studies on peripheral nerve injury.
authors.affiliation: University of California Riverside, Department of Bioengineering, Riverside, CA 92521, USA.
authors.forename: M Shahidul
authors.initials: MS
authors.lastname: Islam
authors.forename: Michael C
authors.initials: MC
authors.lastname: Oliveira
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Francis P
authors.initials: FP
authors.lastname: Henry
authors.forename: Mark A
authors.initials: MA
authors.lastname: Randolph
authors.forename: B Hyle
authors.initials: BH
authors.lastname: Park
authors.forename: Johannes F
authors.initials: JF
authors.lastname: de Boer
mesh_terms: D000465:Algorithms; D000818:Animals; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008859:Microscopy, Polarization / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D059348:Peripheral Nerve Injuries / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012584:Sciatic Nerve / Q000293:injuries* / Q000473:pathology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*