Evaluation of ovarian structures using computerized microtomography

Abstract

Visualization and clear understanding of the ovarian structures are important in determining the stage of oestrus, helping to diagnose several pathologies and supporting advances in reproductive technologies. In this research, computerized microtomography (microCT) was used to explore and characterize the ovarian structure of seven mammalian species. Ovaries of rats, female dog, queens, cows, mares, sows and a female donkey were used. After microCT scanning, the same samples were prepared for histologic evaluation, used here as a validation criterion. It was possible to distinguish regions of the cortex and medulla, visualize the morphology and distribution of blood vessels, clearly observe corpus luteum and antral follicles, and visualize oocytes inside some antral follicles. This is the first report using microCT to explore and compare ovarian structures in several domestic mammals. MicroCT revealed great potential for the evaluation of ovarian structures. This research open prospects for the use of computerized tomography (CT) as a non-invasive approach to studying ovarian structures in live animals, which may be especially attractive for scientific study of development of ovarian structures and/or ovarian pathologies in small animals' models.

Morphological and Chemical Investigation of Ovarian Structures in a Bovine Model by Contrast-Enhanced X-ray Imaging and Microscopy

“…A three-dimensional visualization of these structures directly inside the tissues could provide new information about their development/growth. The use of microtomography in studies of the ovary is very recent [ 11 , 24 ], and our group has already demonstrated the feasibility and utility of microCT experiments on human ovarian tissues [ 11 ]. The development of an effective protocol to study these samples is fundamental for visualizing the features of interest as best as possible and for taking full advantage of this powerful three-dimensional imaging mode.…”

Three-Dimensional Micro-Computed Tomography of the Adult Mouse Ovary

“…On the contrary, tomographic methods produce a true 3D reconstruction of an object, with cubic voxels (i.e., image elements) and isotropic resolution, in other words, the space between two tomographic sections (z-axis) equals the resolution of the xy plane (Flannery et al, 1987;Mizutani and Suzuki, 2012). In order to reconstruct the folliculogenetic process inside the volume of the ovary, different attempts have been made using ultrasonography (Mircea et al, 2009;Ginther et al, 2014;Migone et al, 2016), micro-Magnetic Resonance Imaging (µ-MRI) (Hensley et al, 2007), laboratory-based X-ray micro-Computed Tomography (microCT) (Paulini et al, 2017), synchrotron radiation Computed Tomography (SR-CT) (Kim et al, 2012), and phase contrast Computed Tomography (PC-CT) (Pascolo et al, 2019). However, none of them, with the exception of SR-CT-a technique difficult to access-were capable to identify ovarian follicles smaller in size than those present in the pre-ovulatory compartment on the organ surface (e.g., 450 µm in diameter in rat; 10 mm in bovine).…”

Hard and soft X-ray imaging to resolve human ovarian cortical structures

“…During recent years, microCT using laboratory sources has seen an increasing use in biological and medical research areas with the development of the staining methods (Metscher, 2009), proving to be a powerful technique for biomedical studies. Recent advanced synchrotron and laboratory studies reported also investigations of whole ovaries of laboratory animals (Kim et al, 2012;Paulini et al, 2017) and bovines , demonstrating the potentialities of this approach for estimating ovarian reserve or analysing tissue changes in a 3D perspective. However, to the best of our knowledge, there is no literature reporting X-ray microCT of human ovarian tissue, likely in part because of the difficulty in accessing human material for research purposes.…”

“…The improved visualization and clear understanding of human ovary's structures is highly desirable to support diagnostics as well as advances in reproductive technologies (Paulini et al, 2017). Several works have been reported in the literature concerning the ovary anatomy resolved at high resolution (Bukovsky et al, 2004); however, conventional examinations are usually performed with two-dimensional techniques such as visible light and transmission electron (TEM) microscopies (Makabe et al, 2006).…”

“…However, primordial, primary, secondary and little antral follicles are too small to be seen with ultrasounds (Williams & Erickson, 2000). Computed tomography (CT) is often used for monitoring and diagnosing cysts and tumours in ovaries (Paulini et al, 2017;Rozenblit et al, 2001;Saksouk & Johnson, 2004), but the resolution offered by clinical CT instruments is not high enough to resolve details of the follicles. The possibility of resolving this type of tissue in a threedimensional (3D) visualization with micrometre resolution is of paramount importance for a comprehensive understanding not only of its morphology but also its physiology.…”