Use of B-mode Ultrasound and Grey-Scale Analysis to Study Uterine Echogenicity in the Pig

Abstract

Abstract. This study was conducted to determine uterine echogenicity by grey-scale analysis (GSA) and transcutaneous ultrasonography in pregnant sows (P-sows; n=16) and gilts (P-gilts; n=13) vs. cyclic gilts (C-gilts; n=9) between days 8 and 16 post ovulation (po) with the aims of testing for feasibility of uterine GSA and of gathering reference data. Estruses and ovulations were hormonally synchronized and the animals artificially inseminated. Ovulation was monitored by ultrasound. The equipment used was a HS 2000 ultrasound unit and a 5 MHz linear probe. Unit settings were standardized for all GSA scanning sessions and the animals crated during scanning. For GSA, cross-sections of the uterine horns were imaged, entirely defined as regions of interest, and pixel analyses done. A total of 342 scanning sessions were performed, 341 GSA accomplished, and 1-13 cross-sections analyzed per session. Comparison of coefficients of variation suggests that analysis of two cross-sections per session is sufficient for a reliable GSA per animal. P-sows and P-gilts were similar in their echogenicity course, but differed from C-gilts. Most noticeable, echogenicity declined in pregnant animals on day 12 po, while it increased in cyclic gilts. In conclusion, the study demonstrates that GSA using transcutaneous ultrasound is a feasible procedure for the determination of uterine echogenicity in the pig, and that pregnant and cyclic pigs differ in the uterine echogenicity, particularly during the time when maternal recognition of pregnancy occurs. Key words: Female pig, Grey-scale analysis, Pregnancy, Ultrasonography, Uterus (J. Reprod. Dev. 56: [444][445][446][447][448] 2010) chogenicity is a valuable parameter in order to define the appearance of a tissue or organ by using B-mode ultrasound. Echogenicity is either described based on a score system, and is rather subjective depending on the assessment of the operator. Alternatively, grey-scale analysis (GSA) is used, which is based on computer-supported pixel quantification and is thus a more objective procedure. In large animal species, GSA has mostly been used to define echogenicity patterns of reproductive tissues such as of testes and accessory glands in growing bulls and rams [1,2], as well as of ovarian structures in mares [3], cows and heifers [4,5], and ewes [6,7]. Also, GSA has been employed for studying endometrial echogenicity in pregnant vs. non-pregnant cows [8][9][10] and the European roe deer [11], and has been advocated as an appropriate procedure for the delineation of uterine diseases in mares [12]. B-mode ultrasound is widely used in pigs too, and is predominantly dedicated to examine genital organs which include the ovaries as well as the pregnant and non-pregnant uterus [13]. While differences in echotexture patterns have been described for the porcine uterus depending on the stage of estrous cycle as well as for the healthy vs. diseased uterus, uterine echogenicity using GSA has never been studied except once in a very preliminarily study on a subset of cyc...

Ultrasound monitoring of blood flow and echotexture of the corpus luteum and uterus during early pregnancy of beef heifers

“…Very few studies have assessed pregnancy-induced changes in uterine echotexture in domestic animals. Of the handful that do exist, differences in uterine echotexture were observed in pregnant compared with cyclic sows from Days 11 to 15 [20]. Differences in uterine echotexture have also been observed from Days 7 to 13 between pregnant and cyclic cows [3,19].…”

Optical density changes in ultrasonographic images of the endometrium and corpus luteum in pregnant and cyclic cows

“…The endometrial echotexture decreases following ovulation, which is linked to edema (7,31). Kauffold et al (15) reported a notable increase in the MGL value during implantation in pigs. Cengiz et al (16) also reported a significant increase in the HOM value in pregnant goats 17 days after mating related to the implantation process.…”

“…While the echotextural changes in the endometrium were evaluated by visualizing ultrasonographic images in initial studies (7,31) two decades ago, computer-assisted image analysis systems are nowadays used in veterinary reproduction (14,15). By allowing quantitative evaluation, computer-assisted image analysis eliminates individual observation bias.…”

“…Recording and analyzing ultrasonic digital images allows quantitative assessments to overcome the subjectivity of visual analysis. This methodology, primarily used in human medicine as a part of evidence-based medicine, was also adapted to farm animal reproduction (14)(15)(16). The ultrasonographic appearance or image pattern of an organ is termed "echotexture".…”

Evaluación del descarte en cerdas: causas, registros reproductivos e inspección en planta de faena

“…Estas últimas imágenes son compatibles con la presencia de colecta purulenta en la luz del útero. Sin embargo, en la práctica, estas imágenes no siempre se interpretan de manera correcta, dado que se necesita entrenamiento y experiencia por parte del operador (Almond et al, 2006;Kauffold et al, 2004Kauffold et al, , 2010.…”