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Qualitative and quantitative ultrasound attributes of maternal‐foetal structures in pregnant ewes
Author(s) -
da Silva PDA,
Uscategui RAR,
Santos VJC,
Taira AR,
Mariano RSG,
Rodrigues MGK,
Simões APR,
Maronezi MC,
Avante ML,
Vicente WRR,
Feliciano MAR
Publication year - 2018
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.13163
Subject(s) - echogenicity , ultrasound , medicine , homogeneous , ultrasonography , gestational age , fetus , pregnancy , anatomy , radiology , obstetrics , biology , mathematics , genetics , combinatorics
Contents The aim of this study was to examine foetal organs and placental tissue to establish a correlation between the changes in the composition of these structures associated with their maturation and the ultrasonographic characteristics of the images. Twenty‐four pregnant ewes were included in the study. Ultrasonography assessments were performed in B‐mode, from the ninth gestational week until parturition. The lungs, liver and kidneys of foetuses and placentomes were located in transverse and longitudinal sections to evaluate the echogenicity (hypoechoic, isoechoic, hyperechoic or mixed) and echotexture (homogeneous and heterogeneous) of the tissues of interest. For quantitative evaluation of the ultrasonographic characteristics, it was performed a computerized image analysis using a commercial software (Image ProPlus ® ). Mean numerical pixel values ( NPV s), pixel heterogeneity (standard deviation of NPV s) and minimum and maximum pixel values were measured by selecting five circular regions of interest in each assessed tissue. All evaluated tissues presented significant variations in the NPV s, except for the liver. Pulmonary NPV mean, NPV min and NPV max decreased gradually through gestational weeks. The renal parameters gradually decreased with the advancement of the gestational weeks until the 17th week and later stabilized. The placentome NPV mean, NPV min and NPV max decreased gradually over the course of weeks. The hepatic tissue did not show echogenicity and echotexture variations and presented medium echogenicity and homogeneous echotexture throughout the experimental period. It was concluded that pixels numerical evaluation of maternal‐foetal tissues was applicable and allowed the identification of quantitative ultrasonographic characteristics showing changes in echogenicity related to gestational age.