Within and between observer agreement on ultrasonic evaluation of bovine ovarian structures

Abstract

A diagnostic ultrasound unit with a 5 MHz probe was used to examine ovarian structures in vitro from 32 reproductive tracts obtained at slaughter from young cows. Agreement between and within observers, and between observers and dissection results was evaluated using the kappa statistic. Agreement was high (kappa from 0.531 to 0.969) for all evaluations of corpora lutea. The sensitivity, specificity and predictive value of both positive and negative findings for presence of a corpus luteum was > 0.9. Agreement between and within observers was little better than chance for follicles measuring 4 to < 6 mm and for follicles measuring 6 to < 10 mm. However, agreement between observers and dissection results indicated that observers could detect follicles 4 to < 6 mm and 6 to < 10 mm (kappa 0.301 to 0.731 and 0.414 to 0.612, respectively). Kappa values within and between observers and between observers and dissection results for observations of follicles measuring > or = 10 mm were almost all > 0.4 indicating that large follicles can be readily detected using ultrasound. It is suggested that further validation of ultrasound methods is needed to determine whether follicles measuring < 4 mm can be accurately identified, and whether follicles can be accurately identified and monitored over a number of days. The ultrasound unit was useful for detecting the presence of corpora lutea and follicles. However, agreement between and within observers on the presence of follicles measuring < 10 mm was poor.

Ultrasonographic reproductive tract measures and pelvis measures as predictors of pregnancy failure and anestrus in restricted bred beef heifers

“…Previous findings indicating the superior ability of ultrasonography to detect the presence of a CL [10] are supported by this study due to the fact that significant proportions of heifers with ultrasonographically visible CLs were assigned RTS 3 or 4.…”

“…The ultrasonographic presence of a corpus luteum (CL) has been used to mark the onset of puberty, has substantial repeatability, is more accurate than blood progesterone determination and is a predictor of reproductive outcome in seasonally bred cows and heifers [9][10][11][12]. Ovary size is associated with antral follicle count (AFC), which in turn is associated with follicular reserve and fertility, whereas AFC is not affected by estrus cycle stage [13,14].…”

Ovarian ultrasound image analysis: follicle segmentation

“…Previous studies dealing with measurement reproducibility and interobserver and intraobserver variability demonstrated that ultrasonography allows accurate measurement of follicular diameter [31], facilitates sequential follicle analysis [32], and that the agreement within and between operators for presence of corpora lutea and follicles larger than 10 mm is comparable with that achieved in radiograms [33]. Pierson and Ginther quantitatively compared ultrasound-based follicle diameter measurements with quantitative measurements on sliced of the excised heifer ovaries and concluded that diagnostic ultrasonography is a reliable method for identifying and measuring follicles [31].…”

“…Pierson and Ginther quantitatively compared ultrasound-based follicle diameter measurements with quantitative measurements on sliced of the excised heifer ovaries and concluded that diagnostic ultrasonography is a reliable method for identifying and measuring follicles [31]. Lean et al demonstrated high agreement between three observers when analyzing ultrasound images of follicles larger than 4 mm [33]. They called for additional validation of image acquisition reproducibility since cross-sections through the longest axis of the follicle may be difficult to obtain reproducibly possibly causing errors in sequential measurements.…”

Applications of Ultrasonography in Dairy Cattle Reproductive Management

“…Ultrasound is a highly sensitive method for detecting the presence of a CL. In one early study, ultrasound examination agreed with dissection 96.9% of the time when a profi cient operator used a high -quality machine (Lean et al, 1992 ).…”