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Introduction and objective: In Europe, nearly every sixth couple in the reproductive age is involuntarily
childless. In about 30%, both male and female reveal fertility problems. In about 10% of infertile men,
azoospermia is the underlying cause. As conventional therapeutic options are limited, surgical testicular sperm
extraction (TESE) is necessary to obtain sperms for assisted reproductive techniques. Regarding the females, up
to 30% of all idiopathic infertilities are due to alterations of the uterine tube So far, no imaging technique, which
does not require any labelling, is available to evaluate the male and female genital tract at a microscopic level
under in vivo conditions. Thus, the aim of this study was to investigate the potential of optical coherence
tomography (OCT) as a non-invasive diagnostic tool in gynaecology and andrology.
Material and Methods: Tissues samples from the bovine testis, epididymis, vas deferens, ovary, oviduct
(ampulla and isthmus) and uterus were obtained immediately after slaughter (14 cows aged 3 to 8 years and 14
bulls aged 3 to 6 years; breeds: Holstein- Friesian, and Deutsches Fleckvieh). Imaging was done by using the US
Food and Drug Administration (FDA) approved probe-based Niris Imaging System (Imalux, Cleveland, Ohio,
USA) and the Telesto 1325 nm OCT System and Ganymede 930 nm OCT System (Thorlabs Inc., Dachau,
Germany). All images obtained were compared to histological images after paraffin embedding and HE
staining.
Results: OCT imaging visualized the microarchitecture of the testis, epididymis, spermatic duct and the ovary,
oviduct and uterus. Using the Thorlabs systems a axial resolution of approx. 5μm and lateral resolution of 8-
15μm could be achieved. Different optical tissue volumes could be visualized, which depends on the optical
penetration depth of the wavelength of the system used. While the tissue volume observed by probe based
Imalux-OCT is similar to the used Thorlabs systems, the optical resolution is reduced. By means of the
microscopic OCT-system differentiation of testical tissue structures like content and diameter of seminiferous
tubules and the epididymal duct was possible. Structures of the female oviduct, like the primary, secondary and
tertiary folds including the typical epithelium consisting of secretory and ciliated cells were identified. Ampulla
and isthmus were clearly differentiated by the height of the folds and the thickness of the smooth muscle layer.
Imaging was successful both from the outside wall and from the inner lumen. After experience with microscopic
OCT-structure identification such structures could also be identified by means of probe based OCT.
Conclusions: Technical improvement of probe-based OCT up to a high-resolution level of nowadays-available
OCT microscopic systems could open up new ways of in vivo imaging in the reproductive tract. Potential
applications could be an OCT-guided testicular biopsy for improving sperm retrieval or microscopic evaluation
of the oviduct by OCT-assisted fertiloscopy. The latter would provide a valuable tool to facilitate the decision of
which type of assisted reproductive techniques might be preferred.
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