2D shear wave elastography in abdominal structures of nursery swine.

BACKGROUND

Ultrasonography is a non-invasive and painless imaging technique widely used in veterinary medicine. In swine, this modality is important due to the anatomical and physiological similarities between this species and humans. 2D Shear Wave Elastography complements B-mode, allowing for both qualitative and quantitative analysis of tissue stiffness without operator interference. In swine, elastography has been used to identify and stage hepatic fibrosis, renal fibrosis, and to evaluate pulmonary diseases. However, the literature still lacks information on the normal values of abdominal structures in nursery-phase swine, particularly regarding elastographic evaluation. This study aimed to standardize the renal, splenic, and hepatic stiffness of nursery swine under two sedation protocols.

METHODS

A total of 22 healthy nursery swine were evaluated. The animals were divided into two groups (11 animals each), and each group received a specific sedation protocol. Fifteen minutes after drug administration, B-mode and elastographic ultrasonographic evaluations of the kidneys, spleen, and liver were performed. At the end of the assessment, all animals were neutered.

RESULTS

The evaluated structures showed similar echogenicities in B-mode. The average length of the left kidney was 62.77 ± 5.66 cm and the right kidney 62.92 ± 5.37 cm. A positive correlation was identified between the size of the left kidney (P = 0.012; c = 0.538) and the right kidney (P = 0.001; c = 0.649) and the animals’ weight.In the elastographic evaluation, the left kidney exhibited an average stiffness of 1.71 ± 0.40 m/s, the right kidney 1.73 ± 0.28 m/s, the spleen 1.77 ± 0.45 m/s, and the liver 1.42 ± 0.16 m/s. No statistical difference was observed between the stiffness of the structures and the sedation protocols used.

CONCLUSIONS

B-mode ultrasonography enabled an effective assessment of the kidneys, spleen, and liver in nursery swine. Additionally, 2D shear wave elastography allowed the assessment of the stiffness of these structures without complications, providing a non-invasive and easily performed approach.