Colposcopic imaging using visible-light optical coherence tomography

Abstract

High-resolution colposcopic optical coherence tomography (OCT) provides key anatomical measures, such as thickness and minor traumatic injury of vaginal epithelium, of the female reproductive tract noninvasively. This information can be helpful in both fundamental investigations in animal models and disease screenings in humans. We present a fiber-based visible-light OCT and two probe designs for colposcopic application. One probe conducts circular scanning using a DC motor, and the other probe is capable of three-dimensional imaging over a 4.6 × 4.6 - mm 2 area using a pair of galvo scanners. Using this colposcopic vis-OCT with both probes, we acquired high-resolution images from whole isolated macaque vaginal samples and identified biopsy lesions.

Fig. 1

Vis-OCT colposcopic imaging system. (a) Schematic of the fiber-based vis-OCT, (b) spectral envelope of the probe beam, (c) point spread function of a mirror signal measured in air. SC, supercontinuum source; FC, fiber coupler; CL, collimator; M, mirror; PC, polarization controller; EP, endoscopic probe; SM, spectrometer.

Fig. 2

Vis-OCT colposcopic imaging probes. (a) and (b) are the schematic and photograph of the circular scanning probe, respectively, (c) and (d) are the schematic and photograph of raster scanning probe, respectively. PSW, power supply wire; RT, rigid tube; FL, focus lens; GW, glass window; M, mirror; DCM, DC motor; DH, dome head; GS, galvo scanners.

Fig. 3

Vis-OCT imaging using the circular scanning probe. (a) A typical circular B-scan image, (b) and (c) are magnified views of the highlighted areas in panel (a), (d) histology of normal macaque vaginal wall. Bars: $100\mu \mathrm{m}$. Yellow and red arrows indicate epithelial layer and connective tissue, respectively.

Fig. 4

Vis-OCT imaging using the raster scanning probe. (a) is a representative B-scan image; (b) and (c) are top and side views of 3-D-rendered vis-OCT dataset, (d) and (e) are cross-sectional OCT and histology images, respectively, of the tissue section from the position indicated by the blue line in panel (b). Green arrows indicate thin horizontal linear textures; yellow and red arrows indicate epithelial layer and connective tissue, respectively.