Ultrasound biomicroscopy: a non-invasive approach for in vivo evaluation of oocytes and small antral follicles in mammals

Abstract

The use of ultrasonography has changed our understanding of the ovarian function in live animals. However, most of the studies that have used ultrasonography to image the ovary have provided data only of structures >1mm in diameter. The recent availability of high-resolution ultrasound technology with high-frequency transducers (25-70 MHz), offers the potential to examine the developmental dynamics of small antral follicles and the cumulus-oocyte complex (COC) in vivo. In this review we provide data from a series of studies performed by Veterinary Biomedical Sciences Laboratory describing the advantages and disadvantages, as well as image characteristics, of ultrasound biomicroscopy (UBM) to study ovarian biology in mammals. Data and images of small ovarian structures in rabbits, cattle, mice and humans are shown. The UBM technique allowed visualisation of small antral follicles ranging in size from 300 to 700 μm in all species examined, as well as COC within follicles in rabbits, cattle and humans. Furthermore, UBM permitted clear distinction of the follicular wall from the surrounding ovarian stroma in cattle and humans. At present, the limited depth of penetration of UBM restricts the use of this technique to an experimental setting. In that regard, further studies using UBM will probably result in a greater understanding of the pattern and control of early antral folliculogenesis and oogenesis.

Validation of ultrasound biomicroscopy for the assessment of xenogeneic testis tissue grafts and cell implants in recipient mice

“…The objective of the present study was to validate the use of UBM histochemical analyses. 1,2,27 UBM has facilitated several fields of basic research and clinical applications, including developmental biology, 28 female reproductive biology, [18][19][20][21][22] cardiology, [29][30][31] neurology, 32 oncology, 13,17,33,34 embryology, 14 and ophthalmology. 10,35,36 In a recent feasibility study, we showed that UBM has the potential to be used as a predictive tool for the development of testis tissue grafts and cell implants.…”

“…11,12 Because of its low cost, high speed, accuracy, and non-invasiveness, UBM has been widely used in imaging of laboratory animals, especially to investigate pathogenesis of diseases and embryonic development of mice. [13][14][15][16][17] This technology has been successfully used in reproductive sciences to visualize the ovarian follicular development and cumulus-oocyte complexes in laboratory animals 18,19 as well as in farm animals 20,21 and humans. 21,22 UBM has also been utilized in three-dimensional (3-D) measurements of melanomas in mice where the UBM-measured dimensions were shown to be in excellent agreement with those measured using the caliper volume of tumors.…”

“…[13][14][15][16][17] This technology has been successfully used in reproductive sciences to visualize the ovarian follicular development and cumulus-oocyte complexes in laboratory animals 18,19 as well as in farm animals 20,21 and humans. 21,22 UBM has also been utilized in three-dimensional (3-D) measurements of melanomas in mice where the UBM-measured dimensions were shown to be in excellent agreement with those measured using the caliper volume of tumors. 13,17 Although UBM has been used in a number of applications including in oncology, embryology, and developmental biology, 23 no study has validated its use for monitoring the developmental changes in tissue grafts/cell implants in vivo.…”

Advancing ovarian folliculometry with selective plane illumination microscopy

“…It is worth noticing that putative COCs appearing as protrusion into the fluid-filled lumen can only be detected in less than 25% of the ovarian follicles by ultrasound biomicroscopy. SPIM far outperforms the ultrasound techniques in terms of the spatial resolution14, and is thus more suitable for small follicle detection.…”