Applicability of B-mode ultrasonography, ARFI elastography and contrast-enhanced ultrasound in the evaluation of chronic kidney disease in dogs

ABSTRACT: The objective of this study was to verify the applicability of B-mode ultrasonography, ARFI elastography and CEUS in the diagnosis of chronic kidney disease and its Stages in dogs. 24 healthy dogs and 28 with CKD were included. In B-mode, the echogenicity, echotexture and cortico-medullary ratio of the kidneys were verified. By elastography, the shear-wave velocity of the cortical (SWVcort) and medullary (SWVmed) regions were determined and tissue deformity was evaluated. Wash-in, wash-out and peak enhancement (TPic) of the contrast in the renal parenchyma were calculated and homogeneity, presence of filling gaps and distinction of filling phases were evaluated by CEUS. Changes in echogenicity, echotexture and cortico-medullary ratio were observed only in sick patients. There was an increase in SWVcort in CKD, with a cutoff point >2.91m/s. Healthy kidneys were non-deformable and 25% had changes in gray scales. There was an increase in wash-in and TPic, changes in filling characteristics, filling failures and difficulty in distinguishing between the Stages in CEUS in CKD. It was found that dogs with CKD 2, 3 and 4 had greater SWVcort and wash-in values than CKD 1. Elastographic and CEUS changes were observed in dogs with CKD, demonstrating the applicability of ultrasonographic techniques in their diagnosis.

RESUMO: O objetivo deste estudo foi verificar a aplicabilidade da ultrassonografia modo-B, elastografia ARFI e CEUS no diagnóstico da doença renal crônica e seus estágios em cães. Foram incluídos 24 cães saudáveis e 28 com DRC. Pelo modo-B, verificou-se ecogenicidade, ecotextura e relação córtico-medular dos rins. Pela elastografia, foram determinadas as velocidades de cisalhamento das regiões cortical (SWVcort) e medular (SWVmed) e foi avaliada a deformidade tecidual. Calculou-se os temos de wash-in, wash-out e pico de intensidade (TPic) do parênquima renal e avaliou-se homogeneidade, presença de falhas e distinção das fases de preenchimento por contraste por meio de CEUS. Alterações em ecogenicidade, ecotextura e relação córtico-medular foram observadas somente em pacientes doentes. Houve aumento da SWVcort na DRC, com ponto de corte >2.91m/s. Rins saudáveis foram não-deformáveis e 25% apresentou alterações nas escalas de cinza. Houve aumento do wash-in e TPic, alterações nas características de preenchimento, falhas e dificuldade para distinguir as fases de preenchimento do contraste nos rins com DRC. Verificou-se que cães com DRC graus 2, 3 e 4 tiveram valores de SWVcort e wash-in maiores que cães com DRC grau 1. Foram obsrervadas alterações elastográfica e de CEUS em cães com DRC, demonstrando a aplicabilidade destas técnicas ultrassonográficas no seu diagnóstico.

Applicability of B-mode ultrasonography, ARFI elastography and contrast-enhanced ultrasound in the evaluation of chronic kidney disease in dogs / Aplicabilidade da ultrassonografia modo-B, elastografia ARFI e ultrassonografia contrastada na avaliação da doença renal crônica em cães

The objective of this study was to verify the applicability of B-mode ultrasonography, ARFI elastography and CEUS in the diagnosis of chronic kidney disease and its Stages in dogs. 24 healthy dogs and 28 with CKD were included. In B-mode, the echogenicity, echotexture and cortico-medullary ratio of the kidneys were verified. By elastography, the shear-wave velocity of the cortical (SWVcort) and medullary (SWVmed) regions were determined and tissue deformity was evaluated. Wash-in, wash-out and peak enhancement (TPic) of the contrast in the renal parenchyma were calculated and homogeneity, presence of filling gaps and distinction of filling phases were evaluated by CEUS. Changes in echogenicity, echotexture and cortico-medullary ratio were observed only in sick patients. There was an increase in SWVcort in CKD, with a cutoff point >2.91m/s. Healthy kidneys were non-deformable and 25% had changes in gray scales. There was an increase in wash-in and TPic, changes in filling characteristics, filling failures and difficulty in distinguishing between the Stages in CEUS in CKD. It was found that dogs with CKD 2, 3 and 4 had greater SWVcort and wash-in values than CKD 1. Elastographic and CEUS changes were observed in dogs with CKD, demonstrating the applicability of ultrasonographic techniques in their diagnosis.(AU)

O objetivo deste estudo foi verificar a aplicabilidade da ultrassonografia modo-B, elastografia ARFI e CEUS no diagnóstico da doença renal crônica e seus estágios em cães. Foram incluídos 24 cães saudáveis e 28 com DRC. Pelo modo-B, verificou-se ecogenicidade, ecotextura e relação córtico-medular dos rins. Pela elastografia, foram determinadas as velocidades de cisalhamento das regiões cortical (SWVcort) e medular (SWVmed) e foi avaliada a deformidade tecidual. Calculou-se os temos de wash-in, wash-out e pico de intensidade (TPic) do parênquima renal e avaliou-se homogeneidade, presença de falhas e distinção das fases de preenchimento por contraste por meio de CEUS. Alterações em ecogenicidade, ecotextura e relação córtico-medular foram observadas somente em pacientes doentes. Houve aumento da SWVcort na DRC, com ponto de corte >2.91m/s. Rins saudáveis foram não-deformáveis e 25% apresentou alterações nas escalas de cinza. Houve aumento do wash-in e TPic, alterações nas características de preenchimento, falhas e dificuldade para distinguir as fases de preenchimento do contraste nos rins com DRC. Verificou-se que cães com DRC graus 2, 3 e 4 tiveram valores de SWVcort e wash-in maiores que cães com DRC grau 1. Foram obsrervadas alterações elastográfica e de CEUS em cães com DRC, demonstrando a aplicabilidade destas técnicas ultrassonográficas no seu diagnóstico.(AU)

Acoustic radiation force impulse (ARFI) elastography to asses maternal and foetal structures in pregnant ewes.

The aim of this study was to evaluate the stiffness of foetal lungs, liver, kidneys and placentomes by acoustic radiation force impulse (ARFI) elastography in ovine and to correlate obtained findings with foetal development. Twenty-four ewes were included, and tissue stiffness of foetal lung, liver, kidney and placentome was measured beginning with 10th gestational week by qualitative-quantitative ARFI elastography. A total of 33 healthy lambs were born. Qualitative elastographic analysis permitted to classify maternal and foetal tissues elasticity in decreasing order as follows: placentome, kidney, liver and lung. Regarding quantitative ARFI elastography data, shear wave velocity (SWV) of foetal lung and liver varied. The lung SWV decreased gradually from the 16th to the 21st gestational week (R2  = 0.80; p < 0.001), while liver SWV increased gradually from the 14th to 21st gestational week (R2  = 0.80; p < 0.001). In contrast, the kidneys and placentomes SWV's remained constant through gestation (p = 0.076; and 0.34). ARFI elastography was shown feasible for evaluation of maternal and foetal tissues stiffness in the ovine model. It can be used to demonstrate pulmonary and hepatic stiffness modifications during foetal development.