Use of ultrasound biomicroscopy to image human ovaries in vitro

Abstract

To test the hypothesis that ultrasound biomicroscopy is an effective tool for imaging human ovaries in vitro. This was a prospective, observational study of 11 women (mean age, 48.9 +/- 2.3 years; range, 40-65 years) undergoing unilateral or bilateral oophorectomy. Ovaries were obtained in the operating room and imaged in a cooled saline bath using conventional two-dimensional (2D) ultrasound. Follicles identified using conventional 2D ultrasound were then imaged in a cooled saline bath using ultrasound biomicroscopy. Ovaries were then placed in 10% neutral-buffered formaldehyde and transported to the Pathology Department for histological evaluation. Digital images of individually identified ovarian follicles using conventional ultrasound, ultrasound biomicroscopy and histology were obtained (n = 22). Thicknesses of the follicle wall, granulosa layer and theca interna layer were measured using standardized techniques. The imaging sensitivity, defined as the smallest follicle visualized, was greater using ultrasound biomicroscopy (0.33 +/- 0.07 mm) than it was using conventional ultrasound (1.5 +/- 0.21 mm; P < 0.0001). The mean follicle wall thickness was greater using conventional ultrasound (0.675 +/- 0.039 mm) compared with ultrasound biomicroscopy (0.254 +/- 0.017 mm), which in turn, was greater than that measured by histology (0.160 +/- 0.009 mm) (P < 0.0001). The mean granulosa and theca layer thickness measurements, respectively, were greater using ultrasound biomicroscopy (0.067 +/- 0.004 mm; 0.186 +/- 0.014 mm) compared with histology (0.034 +/- 0.002 mm; 0.126 +/- 0.008 mm) (P < or = 0.001). Protrusions from the follicle wall into the antrum, believed to represent cumulus-oocyte complexes, were visualized in five of 22 follicles using ultrasound biomicroscopy. The ultrasound biomicroscope was an effective tool to image human ovaries in vitro. Ultrasound biomicroscopy provided greater sensitivity and resolution for imaging ovarian follicles compared with conventional 2D ultrasonographic techniques.