Characterization of uterine involution using B-mode ultrasonography, color Doppler and elastography (acoustic radiation force impulse) for assessing postpartum in Santa Inês ewes

The aim of this study was to investigate uterine involution using ultrasonography techniques during postpartum. Postpartum ultrasonography evaluation (B-mode, color Doppler and Acoustic Radiation Force Impulse elastography) of the uterus was performed by transabdominal approach at immediate after birth and sequentially every 48 hours, during 30 days. The uterine echotexture did not present significant variations (P >0.05) being homogeneous in most evaluations; echogenicity of the uterus increased along the evaluation period (P =0.0452). Progressive and remarkable decrease of the total uterine diameter (UD) were observed (P <0.0001), especially during the first days postpartum. The thickness of uterine wall gradually decreased, as well the endometrial, myometrium and lumen diameters (P <0.0001). Uterine blood flow was assessed by Doppler and decreased during postpartum period, being significantly lower (P=0.0225) on the 30th day of postpartum. Uterine parenchyma presented as homogeneous dark areas (not deformable) on qualitative ultrasound elastography and the means shear velocity values of the uterine wall on quantitative elastography did not differ. This is the first study that evaluate the stiffness of uterine wall in healthy ewes, providing baseline data about quantitative and qualitative stiffness of the normal uterus, and it may be a useful tool for early diagnosis of uterine alterations during the postpartum period, using the reference parameter established for the assessment of uterine integrity during postpartum period.(AU)

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs

ABSTRACT: Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P 0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P 0.001). On cortical region the SWV was significantly higher (P 0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P 0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.

RESUMO: O objetivo foi avaliar a precisão da elastografia na diferenciação entre lentes normais e de catarata. Cento e quarenta e cinco olhos de 98 cães foram divididos em grupos de acordo com o estágio de maturação da catarata. Quarenta e dois olhos foram submetidos à facoemulsificação. Parâmetros biométricos, ecogenicidade e padrões de ecotextura das câmaras anterior, posterior e vítrea, lente e complexos retina-coróide-esclera foram avaliados por ultrassonografia ocular nos modos A e B. A deformabilidade e a coloração (cor azul = indicou estruturas menos rígidas, cor vermelha = estruturas mais rígidas) das lentes foram avaliadas pelo elastograma. A velocidade da onda de cisalhamento (SWV; m/s) foi calculada em três regiões da lente, tanto no córtex quanto no núcleo. A SWV do núcleo foi estatisticamente diferente entre as lentes normais e com catarata e entre os estágios da catarata (P 0,001). Lentes saudáveis e cataratas incipientes tinham um núcleo mais rígido. Cataratas maduras apresentaram menor rigidez nuclear (P 0,001). Na região cortical, a SWV foi significativamente maior (P 0,01) nas cataratas intumescentes e incipientes. Uma SWV menor que 2,67m/s indica catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. Uma SWV superior a 2,66m/s está associada à catarata normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes normais de olhos saudáveis e afetadas e a classificação dos estágios evolutivos. A elastografia se mostrara uma ferramenta viável para avaliar as lentes de cães, caracterizando os tipos de catarata e demonstrando maior rigidez das lentes doentes.

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs / Acurácia da elastografia ARFI na diferenciação dos estágios da catarata em cães

Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P<0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P<0.001). On cortical region the SWV was significantly higher (P<0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P<0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.(AU)

O objetivo foi avaliar a precisão da elastografia na diferenciação entre lentes normais e de catarata. Cento e quarenta e cinco olhos de 98 cães foram divididos em grupos de acordo com o estágio de maturação da catarata. Quarenta e dois olhos foram submetidos à facoemulsificação. Parâmetros biométricos, ecogenicidade e padrões de ecotextura das câmaras anterior, posterior e vítrea, lente e complexos retina-coróide-esclera foram avaliados por ultrassonografia ocular nos modos A e B. A deformabilidade e a coloração (cor azul = indicou estruturas menos rígidas, cor vermelha = estruturas mais rígidas) das lentes foram avaliadas pelo elastograma. A velocidade da onda de cisalhamento (SWV; m/s) foi calculada em três regiões da lente, tanto no córtex quanto no núcleo. A SWV do núcleo foi estatisticamente diferente entre as lentes normais e com catarata e entre os estágios da catarata (P<0,001). Lentes saudáveis e cataratas incipientes tinham um núcleo mais rígido. Cataratas maduras apresentaram menor rigidez nuclear (P<0,001). Na região cortical, a SWV foi significativamente maior (P<0,01) nas cataratas intumescentes e incipientes. Uma SWV menor que 2,67m/s indica catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. Uma SWV superior a 2,66m/s está associada à catarata normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes normais de olhos saudáveis e afetadas e a classificação dos estágios evolutivos. A elastografia se mostrara uma ferramenta viável para avaliar as lentes de cães, caracterizando os tipos de catarata e demonstrando maior rigidez das lentes doentes.(AU)

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs / Acurácia da elastografia ARFI na diferenciação dos estágios da catarata em cães

Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P<0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P<0.001). On cortical region the SWV was significantly higher (P<0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P<0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.(AU)

O objetivo foi avaliar a precisão da elastografia na diferenciação entre lentes normais e de catarata. Cento e quarenta e cinco olhos de 98 cães foram divididos em grupos de acordo com o estágio de maturação da catarata. Quarenta e dois olhos foram submetidos à facoemulsificação. Parâmetros biométricos, ecogenicidade e padrões de ecotextura das câmaras anterior, posterior e vítrea, lente e complexos retina-coróide-esclera foram avaliados por ultrassonografia ocular nos modos A e B. A deformabilidade e a coloração (cor azul = indicou estruturas menos rígidas, cor vermelha = estruturas mais rígidas) das lentes foram avaliadas pelo elastograma. A velocidade da onda de cisalhamento (SWV; m/s) foi calculada em três regiões da lente, tanto no córtex quanto no núcleo. A SWV do núcleo foi estatisticamente diferente entre as lentes normais e com catarata e entre os estágios da catarata (P<0,001). Lentes saudáveis e cataratas incipientes tinham um núcleo mais rígido. Cataratas maduras apresentaram menor rigidez nuclear (P<0,001). Na região cortical, a SWV foi significativamente maior (P<0,01) nas cataratas intumescentes e incipientes. Uma SWV menor que 2,67m/s indica catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. Uma SWV superior a 2,66m/s está associada à catarata normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes normais de olhos saudáveis e afetadas e a classificação dos estágios evolutivos. A elastografia se mostrara uma ferramenta viável para avaliar as lentes de cães, caracterizando os tipos de catarata e demonstrando maior rigidez das lentes doentes.(AU)

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)

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 of testicular disorders in dogs: preliminary results / Elastografia acoustic radiation force impulse (ARFI) de afecções testiculares em cães: resultados iniciais

The aim of this study was to describe the use of acoustic radiation force impulse (ARFI) elastography in the evaluation of testicular disorders in dogs. Eighteen dogs with testicular disorders (thirty-six testicles) were assessed. Echotexture, size, contours and margins of testes were analysed by ultrasonography. Deformities and tissue stiffness (greyscale and homogenous or heterogeneous) were evaluated by qualitative elastography and shear velocity was determined quantitatively. Subsequent to orchiectomy, testicular samples were collected for histopathology analysis and thirty-six disorders were identified. Qualitative elastography revealed that normal healthy testicular tissues were homogenous and not pliable while the affected testicles had alterations in tissue stiffness and homogeneity. The values obtained for quantitative elastography of the testicular tissues were: normal/healthy - 1.30±0.12 m/s; degenerated - 0.97±0.08 m/s; atrophied - 2.00±0.35 m/s; hypoplastic - 0.82±0.2 m/s; cystic - 1.32±0.18 m/s; orchitis - 2.68±0.42 m/s; interstitial cell tumours - 3.32±0.65 m/s; sertolioma - 2.99±0.07 m/s and leydigoma - 2.73±0.37. ARFI elastography of abnormal testes proved to be an applicable and complementary technique in the diagnosis of testicular disease in dogs.(AU)

O objetivo deste estudo foi descrever o uso da elastografia ARFI (acoustic radiation force impulse) para avaliar as afecções testiculares em cães. Dezoito cães com distúrbios testiculares (36 testículos) foram avaliados. Ecotextura, tamanho, contornos e margens dos testículos foram avaliados por meio da ultrassonografia modo-B. A presença de deformidades e a rigidez tecidual (escala de cinza; homogênea ou heterogênea) foram avaliadas pela elastografia qualitativa; e a velocidade de cisalhamento foi determinada pela avaliação quantitativa. Amostras dos tecidos testiculares foram coletadas após orquiectomia para o diagnóstico histopatológico. Após ultrassonografia, orquiectomia e histopatologia, foram identificados 36 distúrbios em tecidos testiculares. Durante a elastografia qualitativa, os tecidos normais apresentaram-se homogêneos e não deformáveis; os testículos alterados demonstraram alterações na rigidez tecidual e de sua homogeneidade. Para a elastografia quantitativa, os valores obtidos foram: tecidos normais - 1,30±0,12m/s; degenerados - 0,97±0,08m/s; atrofiados - 2,00±0,35m/s; hipoplásicos - 0,82±0,2m/s; cistos - 1,32±0,18m/s; orquite - 2,68±0,42m/s; tumores de células intersticiais - 3,32±0,65m/s; sertolioma - 2,99±0,07m/s; e leydigoma - 2,73±0,37m/s. A elastografia ARFI de testículos anormais em cães demonstrou ser uma técnica aplicável e complementar para o diagnóstico de doenças testiculares nessa espécie animal.(AU)

ARFI elastography of healthy adults felines testes

Background: Elastography is a promising ultrasound technique that evaluates tissue elasticity, characteristic related to the ability of a body or substance to return to its original size or shape after it is deformed by an external force. In veterinary, the research conducted for the standardization of elastography in tissue evaluation of the animals are recent and given the importance of this new ultrasound technique for studying the stiffness of various tissues and its recent application in veterinary medicine, the aims of this study were to describe the use of ARFI elastography for evaluating the testicular stroma in adults felines and to establish normal reference values for this tissue.Materials, Methods & Results: Forty five male cats were submitted to B-Mode ultrasonography and ARFI Elastography, by qualitative and quantitative analysis to describe baseline data for the study of domestic feline testes. The echotexture (homogeneous or heterogeneous) ecogenicity (hypo, hyperechoic or mixed), size (increased, decreased or normal) and contours and margins (regular or irregular) of the testes (right and left) were assessed and categorised via B-Mode ultrasound in longitudinal and transverse sections for research of structural changes, such as the presence of cystic areas or masses. Qualitative and quantitative elastography of the testes in felines was performed without difficulty and without sedation. Due to the location of the evaluated structures, there was no interference from movements that hindered the acquisition of the measurements. During qualitative elastography, the felines demonstrated a homogenous and not pliable testicular stroma. The rigidity observed in the testicles of felines was lower compared to the adjacent tissue.[...](AU)

ARFI elastography of healthy adults felines testes

Background: Elastography is a promising ultrasound technique that evaluates tissue elasticity, characteristic related to the ability of a body or substance to return to its original size or shape after it is deformed by an external force. In veterinary, the research conducted for the standardization of elastography in tissue evaluation of the animals are recent and given the importance of this new ultrasound technique for studying the stiffness of various tissues and its recent application in veterinary medicine, the aims of this study were to describe the use of ARFI elastography for evaluating the testicular stroma in adults felines and to establish normal reference values for this tissue.Materials, Methods & Results: Forty five male cats were submitted to B-Mode ultrasonography and ARFI Elastography, by qualitative and quantitative analysis to describe baseline data for the study of domestic feline testes. The echotexture (homogeneous or heterogeneous) ecogenicity (hypo, hyperechoic or mixed), size (increased, decreased or normal) and contours and margins (regular or irregular) of the testes (right and left) were assessed and categorised via B-Mode ultrasound in longitudinal and transverse sections for research of structural changes, such as the presence of cystic areas or masses. Qualitative and quantitative elastography of the testes in felines was performed without difficulty and without sedation. Due to the location of the evaluated structures, there was no interference from movements that hindered the acquisition of the measurements. During qualitative elastography, the felines demonstrated a homogenous and not pliable testicular stroma. The rigidity observed in the testicles of felines was lower compared to the adjacent tissue.[...]

ELASTOGRAFIA ACOUSTIC RADIATION FORCE IMPULSE (ARFI) DOS TECIDOS HEPÁTICO E ESPLÊNICO DE PACIENTES CANINOS AFETADOS PELA SÍNDROME BRAQUICEFÁLICA

O presente estudo teve como objetivo avaliar a rigidez tecidual de fígado e baço de cães braquicefálicos e sua correlação com a síndrome braquicefálica. A metodologia foi realizada com base em elastografia ARFI com utilização do aparelho ACUSON S2000/SIEMENS, com transdutores multifrequenciais convexo e linear, e softwares específicos. Foram selecionados 48 pacientes braquicefálicos e 22 controles mesocefálicos, com idade entre um a seis anos e faixa de peso delimitada. As raças braquicefálicas apresentaram rigidez hepática (lobos mediais: 1.52 m/s ± 0.36; lobo esquerdo lateral: 1.47 m/s ± 0.47; lobo direito lateral: 1.20 m/s ± 0.29 e lobo caudado: 1.23 m/s ± 0.39) e esplênica (2.51 m/s ± 0.45) significativamente maior do que cães mesocefálicos (Fígado: lobos mediais: 0.96 m/s ± 0.10, lobo esquerdo lateral: 0.93 m/s ± 0.11, lobo direito lateral: 0.74 m/s ± 0.08, lobo caudado: 0.76 m/s ± 0.10; baço: 2.29 m/s ± 0.34) pela análise de variâncias ANOVA. Análise dos componentes principais fora realizada, na qual dois componentes (velocidades de cisalhamento do lobo esquerdo lateral, lobos mediais e lobo caudado versus hemoglobina, hematócrito, eritrócitos e ALT) explicaram 70% das variações obtidas entre os grupos. Cães braquicefálicos apresentaram maior rigidez de parênquima hepático e esplênico avaliado por elastografia ARFI quando comparados a cães mesocefálicos.

The present study aimed to evaluate the hepatic and spleen stiffness of brachycephalic dogs and its correlation with the brachycephalic syndrome. The tissue elasticity was evaluated by ARFI (Acoustic radiation force impulse) elastography, with convex and linear multifrequential transducers and specific software. Forty-eight brachycephalic and 22 mesocephalic dogs, with an age range between one to six years old and weight range also pre-define. The brachycephalic breeds showed values of liver stiffness (medial lobes: 1.52 m/s ± 0.36; left lateral lobe: 1.47 m/s ± 0.47; right lateral lobe: 1.20 m/s ± 0.29 and caudate lobe: 1.23 m/s ± 0.39) and spleen stiffness (2.51 m/s ± 0.45) significantly higher than the mesocephalic dogs (Liver: medial lobes: 0.96 m/s ± 0.10, left lateral lobe: 0.93 m/s ± 0.11, right lateral lobe: 0.74 m/s ± 0.08, caudate lobe: 0.76 m/s ± 0.10; spleen: 2.29 m/s ± 0.34) by the analyses of variances ANOVA. A principal component analysis was performed in which two components (shear wave velocities of the left lateral, medial and caudate lobes versus hemoglobin, hematocrit erythrocytes and ALT) explained 70% of the variances between the groups. Brachycephalic dogs had higher spleen and liver stiffness when compared with mesocephalic dogs.

ELASTOGRAFIA Acoustic Radiation Force Impulse (ARFI) EM LENTES DE CÃES COM CATARATA

Os objetivos deste estudo foram avaliar a acurácia da elastografia Acoustic Radiation Force Impulse na diferenciação entre lentes normais e com catarata, além de correlacionar o grau de rigidez da lente intraocular com os parâmetros avaliados durante a facoemulsificação (tempo de ultrassom, controle de vácuo e quantitativo de solução salina balanceada). No total, 145 olhos de 98 cães foram avaliados e divididos em grupos de lentes normais e de acordo com o estágio da catarata.. A velocidade de cisalhamento (VC) (m/s) do núcleo foi estatisticamente diferente entre lentes normais e lentes com catarata, bem como entre os estágios da catarata (P <0,001). As lentes saudáveis e as cataratas incipientes tinham um núcleo mais rígido do que as intumescentes, as imaturas e as hipermaturas. A catarata madura apresentou maior rigidez nuclear (P <0,001). Na região cortical, a VC foi maior (P <0,01) nas cataratas intumescentes e incipientes. VC inferiores a 2,67 m/s indicam que a lente apresenta catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23 m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. VC superiores a 2,66 m/s estão associadas às cataratas normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes saudáveis e cataratosas e a classificação de seus estágios evolutivos da catarata. Dentre os pacientes avaliados, 42 olhos, de 26 cães, foram submetidos à facoemulsificação. Houve correlação entre o grau de rigidez da lente nas regiões cortical e nuclear (p=00165; r=0,37) e entre o quantitativo de solução salina balanceada utilizada e o tempo cirúrgico (p<0,01; r=0,73). O grau de rigidez da lente não apresentou correlação com os parâmetros cirúrgicos da facoemulsificação. O tempo cirúrgico (p=0,130), o quantitativo de solução salina balanceada (p=0,174), e o vácuo aplicado (p=0,167) foram estatisticamente similares independente do estágio evolutivo. Embora a técnica tenha se mostrado exequível para a avaliação da lente, a sensibilidade e a especificidade não são suficientes para considerar o método como ferramenta de diagnóstico da afecção.

The goals of this study were to evaluate the accuracy of the acoustic radiation force impulse in the differentiation between normal and cataract lenses and correlate the degree of lens rigidity to the parameters evaluated during phacoemulsification. In total, 145 eyes of 98 dogs were assessed and divided into groups according to the cataract stage. The shear velocity of the nucleus was statistically different between the normal lenses and lenses with cataracts, and between the stages of cataract (P<0.001). Healthy lenses and incipient cataracts had a more rigid nucleus than those affected by intumescent, immature and hypermature cataracts. Mature cataracts presented greater nuclear rigidity when compared to the others (P<0.001). On cortical region, shear velocity was significantly higher (P<0.01) in intumescent and incipient cataracts than in the other stages. SWV less than 2.67 m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23 m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. Shear velocity greater than 2.66 m/s are associated with normal or incipient cataract, presenting sensitivity of 94% and specificity of 84%. The qualitative method allowed differentiation between healthy and affected lenses and the classification of the evolutionary stages of the cataract. Forty-two eyes of 26 dogs were submitted to phacoemulsification, after finding significant visual deficiency and normality of retinal parameters to the electroretigraphy examination. There was a correlation between the degree of stiffness of the lens in the cortical and nuclear regions (p = 00165; r = 0.37) and between the BSS quantitative and surgical time (p <0.01; r = 0.73). The degree of stiffness of the lens did not correlate with surgical parameters of phacoemulsification (time, vacuum and quantitative BSS). The surgical time (p = 0.130), the quantitative BSS (p = 0.174) as well as the applied vacuum (p = 0.167) were similar regardless of the evolutionary stage of the cataract. Although the elastographic method proved feasible for evaluating the lens of dogs, its sensitivity and specificity were not sufficient to consider the method applicable to the diagnosis of this condition in the present study.

ULTRASSONOGRAFIAS MODO-A, MODO-B E ELASTOGRAFIA ACOUSTIC RADIATION FORCE IMPULSE DO BULBO OCULAR DE CÃES BRAQUICEFÁLICOS

Estudaram-se olhos de cães braquicefálicos por elastografia acoustic radiation force impulse (ARFI) estabelecendo-se padrões de referência qualiquantitativos relacionados com a rigidez de estruturas oculares. Compararam-se imagens obtidas à ultrassonografia ocular convencional com às geradas pelo método elastográfico ARFI. Quarenta e dois cães braquicefálicos (16 Shih Tzus, 11 Buldogues Ingleses, 11 Buldogues Franceses e 4 Pugs), adultos, com um a seis anos de idade, sendo 10 machos e 32 fêmeas, foram incluídos no estudo, totalizando 84 olhos. Os animais foram submetidos a exames físico, laboratorial e oftálmico. Constatadas as boas condições de saúde, foram submetidos à ultrassonografia e à elastografia qualitativa e quantitativa, com ênfase para o nervo óptico, o corpo ciliar e a lente. Ao exame ultrassonográfico, o diâmetro axial horizontal dos olhos foi de 19,52±1,22 mm; o comprimento da câmara anterior foi de 3,06±0,73 mm; da câmara vítrea foi de 9,5±0,46 mm e a espessura da lente foi de 6,93±0,71 mm. Ao modo-B, o nervo óptico mostrou-se hipoecogênico e os humores aquoso e vítreo apresentaram-se anecogênicos. As cápsulas da lente exibiram padrão hiperecogênico, enquanto, seu interior revelou-se anecoico. O complexo retina-coróide-esclera apresentou-se como estrutura hiperecogênica única. À elastografia qualitativa, observaram-se características de homogeneidade em nervo óptico e corpo ciliar e imagens em mosaico referentes ao interior da lente, bem como dos humores aquoso e vítreo. As cápsulas anterior e posterior da lente apresentaram aspecto homogêneo e coloração negra devido ao seu alto grau de rigidez. Em relação ao método quantitativo, o valor médio de velocidade de cisalhamento do nervo óptico foi de 1,01±0,27 m/s, do corpo ciliar, em região temporal, foi de 0,91±0,24 m/s e, em região nasal, de 0,91±0,3 m/s. Para lente, observaram-se valores acima das detectáveis pelo software (X.XX m/s). A elastografia forneceu informações adicionais àquelas obtidas à ultrassonografia oftálmica, configurando-se como método factível em cães, não invasivo e de rápida consecução

Eyes from brachycephalic dogs were studied by acoustic radiation force impulse elastography (ARFI) to establish quantitative and qualitative reference values of some ocular structures. Images obtained by conventional ocular ultrasonography were compared with images obtained by ARFI elastography. Eighty-four eyes from 42 adult (ranging between one to six years) brachycephalic dogs, (16 Shih Tzus, 11 French Bulldogs, 11 English Bulldogs, and 4 Pugs), 10 male and 32 female, were included in this study. The animals were submitted to physical, laboratory, ophthalmic examinations, ocular ultrasonography and elastography, emphasizing the optic nerve, ciliary body, and lens. A-mode US mean values were 19.52 ± 1.99 mm for axial length, 3.06 ± 0.73 mm for anterior chamber length, 9.50 ± 0.46 mm for vitreous chamber length, and 6.93 ± 0.71 mm for lens thickness. On B-mode, the optic nerve presented hypoechoic, whereas aqueous and vitreous humors presented anechoic. Anterior and posterior lens capsules presented hyperechoic and the lens revealed anechoic. The retina-choroide-sclera complex presented hyperechoic. On qualitative elastography, the optic nerve and ciliary body were homogeneous. Anterior and posterior lens capsules were homogeneous and more rigid than other structures. The lens presented heterogeneous, the aqueous and vitreous humors showed mosaic-like images. Quantitative elastography mean of optic nerve was 1.01 ± 0.27 m/s, temporal ciliary body was 0.91 ± 0.24 m/s, nasal ciliary body was 0.91 ± 0.3 m/s and lens values were out of range: X.XX m/s. The exam is feasible, fast, non-invasive and provides complementary information to ultrasound

Tenderness Analysis of Muscles Fixed in Formaldehyde and Kept in 0.5% Sodium Benzoate and 0.5% Acetic Acid Solution / Análise da textura de músculos submetidos à fixação em formaldeído e conservação em solução de benzoato de sódio 0,5% e ácido acético 0,5%

Background: Tissue texture, or tenderness, may be checked-out by analyzing the force necessary to cause muscle fibers rupture (shearing force) and the result is expressed in kilogram-force (kgf). The aim of this paper was to analyze the texture of broiler chicken breast muscles fi xed in a 10% formaldehyde solution and kept in a 0.5% sodium benzoate and 0.5% acetic acid solution up to 180 days so any alteration regarding resistance and the best moment for dissection could be described. Materials, Methods & Results: Forty chicken breasts were used and muscle texture was analyzed by the shearing force whose values were correspondent to the maximum force necessary to chisel the samples. Eight of 40 breasts were taken as a control group (fresh muscles). The remaining breast muscles were fi xed in a 4% formaldehyde solution and kept in plastic containers with this solution during seven days and, then, eight breasts went through texture analysis. The 24 remaining breasts were set in plastic containers with 0.5% sodium benzoate and 0.5% acetic acid solution. The texture analyses were taken out at 30, 90 and 180 days of conservation, and eight breasts were used in each time. The shearing force was obtained for each sample and, just before cutting, muscles were washed in running water for 24 h so the excess of the conservation agent could be removed. Data were submitted to statistic

Background:  Tissue  texture,  or  tenderness,  may  be  checked-out  by  analyzing  the  force  necessary  to  cause  muscle  fibers rupture  (shearing  force)  and  the  result  is  expressed  in  kilogram-force  (kgf).  The  aim  of  this  paper  was  to  analyze  the  texture of  broiler  chicken  breast  muscles  fi  xed  in  a  10%  formaldehyde  solution  and  kept  in  a  0.5%  sodium  benzoate  and  0.5%  acetic acid  solution  up  to  180  days  so  any  alteration  regarding  resistance  and  the  best  moment  for  dissection  could  be  described.Materials,  Methods  &  Results:  Forty  chicken  breasts  were  used  and  muscle  texture  was  analyzed  by  the  shearing  force whose  values  were  correspondent  to  the  maximum  force  necessary  to  chisel  the  samples.  Eight  of  40  breasts  were  taken as  a  control  group  (fresh  muscles).  The  remaining  breast  muscles  were  fi  xed  in  a  4%  formaldehyde  solution  and  kept in  plastic  containers  with  this  solution  during  seven  days  and,  then,  eight  breasts  went  through  texture  analysis.  The  24 remaining  breasts  were  set  in  plastic  containers  with  0.5%  sodium  benzoate  and  0.5%  acetic  acid  solution.  The  texture analyses  were  taken  out  at  30,  90  and  180  days  of  conservation,  and  eight  breasts  were  used  in  each  time.  The  shearing force  was

Análise da textura de músculos submetidos à fixação em formaldeído e conservação em solução de benzoato de sódio 0, 5% e ácido acético 0, 5% / Tenderness analysis of muscles fixed in formaldehyde and kept in 0, 5% sodium benzoate and 0, 5% acetic acid solution

Background: Tissue texture, or tenderness, may be checked-out by analyzing the force necessary to cause muscle fibers rupture (shearing force) and the result is expressed in kilogram-force (kgf). The aim of this paper was to analyze the texture of broiler chicken breast muscles fixed in a 10% formaldehyde solution and kept in a 0.5% sodium benzoate and 0.5% acetic acid solution up to 180 days so any alteration regarding resistance and the best moment for dissection could be described. Materials, Methods & Results: Forty chicken breasts were used and muscle texture was analyzed by the shearing force whose values were correspondent to the maximum force necessary to chisel the samples. Eight of 40 breasts were taken as a control group (fresh muscles). The remaining breast muscles were fixed in a 4% formaldehyde solution and kept in plastic containers with this solution during seven days and, then, eight breasts went through texture analysis. The 24 remaining breasts were set in plastic containers with 0.5% sodium benzoate and 0.5% acetic acid solution. The texture analyses were taken out at 30, 90 and 180 days of conservation, and eight breasts were used in each time. The shearing force was obtained for each sample and, just before cutting, muscles were washed in running water for 24 h so the excess of the conservation agent could be removed. Data were submitted to statistical analysis by the 5% Tukey's test. The average shearing force of the control, formaldehyde and 30-day sodium benzoate and acetic acid groups differed among them and from the 90-day and 180-day of sodium benzoate and acetic acid groups. The average shearing forces of the two last groups did not statistically differ among them. Discussion: The longer the muscles were kept in the sodium benzoate and acetic acid solutions, the more they became soft, and the shearing force decreased from 21.46 Kgf (seven days of conservation) to 19.20 Kgf (30 days), 17.23 Kgf (90 days) and 16.32 Kgf (180 days) not reaching, however, values from 8.97 to 15.31 Kgf, as described in chicken breasts conserved in 96oGL ethylic alcohol. The average shearing force of chicken breasts conserved in sodium benzoate and acetic acid progressively decreased during 180 days of conservation, when it reached a value of 16.32 Kgf, similar to the value of 15.32 Kgf of chicken breasts conserved for 45 days in formaldehyde. By the seventh day of conservation in 10% formaldehyde, samples presented an average shearing force of 21.46 Kgf, which was higher than the 15.33 Kgf of chicken breasts conserved during 45 days or the 14.74 to 17.37 Kgf of the same tissue kept up to a year in formaldehyde solution. It was concluded that conservation of breast broiler chickens fixed in formaldehyde and conserved in sodium benzoate and acetic acid made them softer through within 180 days, resulting in a better structure malleability and suggesting that dissection of anatomical muscle pieces may occur in an easier way in this moment. Although the sodium benzoate and acetic acid effect in texture of broiler chicken muscle tissue fixed in formaldehyde has been studied, it is believed that, due this great tissue homogeneity, these data might be taken or used as basis to similar studies in other species.

Análise da textura de músculos peitorais submetidos à fixação e conservação em álcool / Tenderness analysis of muscles fixed and kept in alcohol

A textura, ou maciez, pode ser avaliada pela mensuração da força necessária para ocorrer o cisalhamento das fibras musculares. Objetivou-se, nesse trabalho, a análise da textura de músculos submetidos à fixação e conservação em álcool, ao longo de um ano, mediante uso de um aparelho analisador de textura. Foram utilizados 48 peitos de frangos jovens, pesados, fixados e conservados em álcool etílico 96° GL. As análises foram realizadas após 15, 30, 90, 180 e 360 dias de conservação, além do grupo controle de músculos frescos. Os valores da força de cisalhamento dos diferentes grupos aumentaram progressivamente de 3,38 (grupo controle) até 15,31 Kgf (180 dias), caindo para 9,53 Kgf após 360 dias. Concluiu-se que quando músculos são submetidos à fixação e conservação em álcool 96° GL, ocorre diminuição da maciez, tornando-os quase cinco vezes mais rígidos ao corte após seis meses, e três vezes mais rígidos após um ano. Sugere-se que a dissecção de peças anatômicas musculares ocorra até 90 dias após fixação e conservação em álcool 96° GL ou ao redor de um ano nesse agente conservante, pois há menor rigidez tissular nesses períodos. Embora se tenha estudado o efeito do álcool na textura de tecido muscular de aves, acredita-se que, devido à grande homogeneidade tissular neste caso, tais dados possam ser extrapolados ou servir de base para estudos similares em outras espécies.(AU)

Texture, or tenderness, may be evaluated by measuring the force necessary to cause rupture of muscle fibers. The aim of this paper was to analyze the texture of muscles fixed and kept in alcohol, throughout a year, by using a texture analyzer. Forty eight poultry breasts were weighted, fixed and kept in a 96° GL ethylic alcohol solution. Analyses were performed at 15, 30, 90, 180 and 360 days of conservation, besides the one of the control group of fresh breasts. Values of shear forces of different groups increased progressively from 3.38 (control group) to 15.31 Kgf (180 days), decreasing to 9.53Kgf after 360 days. It was concluded that when muscles are fixed and kept in ethylic alcohol 96° GL the tenderness is decreased, becoming almost five times harder during the first six months and three times harder after a year. It is suggested that muscle anatomic pieces dissection occurs up to 90 days after fixation and conservation in 96° GL alcohol or around 1 year on this conservation product because there is smaller muscle stiffness in these times. Although the alcohol effect in texture of poultry muscle tissue has being studied in this paper, it is believed that, due this great tissue homogeneity, these data might be taken or being basis to similar studies in other species.(AU)

Tenderness Analysis of Muscles Fixed in Formaldehyde and Kept in 0.5% Sodium Benzoate and 0.5% Acetic Acid Solution / Análise da textura de músculos submetidos à fixação em formaldeído e conservação em solução de benzoato de sódio 0,5% e ácido acético 0,5%

Background: Tissue texture, or tenderness, may be checked-out by analyzing the force necessary to cause muscle fibers rupture (shearing force) and the result is expressed in kilogram-force (kgf). The aim of this paper was to analyze the texture of broiler chicken breast muscles fi xed in a 10% formaldehyde solution and kept in a 0.5% sodium benzoate and 0.5% acetic acid solution up to 180 days so any alteration regarding resistance and the best moment for dissection could be described. Materials, Methods & Results: Forty chicken breasts were used and muscle texture was analyzed by the shearing force whose values were correspondent to the maximum force necessary to chisel the samples. Eight of 40 breasts were taken as a control group (fresh muscles). The remaining breast muscles were fi xed in a 4% formaldehyde solution and kept in plastic containers with this solution during seven days and, then, eight breasts went through texture analysis. The 24 remaining breasts were set in plastic containers with 0.5% sodium benzoate and 0.5% acetic acid solution. The texture analyses were taken out at 30, 90 and 180 days of conservation, and eight breasts were used in each time. The shearing force was obtained for each sample and, just before cutting, muscles were washed in running water for 24 h so the excess of the conservation agent could be removed. Data were submitted to statistic

Background:  Tissue  texture,  or  tenderness,  may  be  checked-out  by  analyzing  the  force  necessary  to  cause  muscle  fibers rupture  (shearing  force)  and  the  result  is  expressed  in  kilogram-force  (kgf).  The  aim  of  this  paper  was  to  analyze  the  texture of  broiler  chicken  breast  muscles  fi  xed  in  a  10%  formaldehyde  solution  and  kept  in  a  0.5%  sodium  benzoate  and  0.5%  acetic acid  solution  up  to  180  days  so  any  alteration  regarding  resistance  and  the  best  moment  for  dissection  could  be  described.Materials,  Methods  &  Results:  Forty  chicken  breasts  were  used  and  muscle  texture  was  analyzed  by  the  shearing  force whose  values  were  correspondent  to  the  maximum  force  necessary  to  chisel  the  samples.  Eight  of  40  breasts  were  taken as  a  control  group  (fresh  muscles).  The  remaining  breast  muscles  were  fi  xed  in  a  4%  formaldehyde  solution  and  kept in  plastic  containers  with  this  solution  during  seven  days  and,  then,  eight  breasts  went  through  texture  analysis.  The  24 remaining  breasts  were  set  in  plastic  containers  with  0.5%  sodium  benzoate  and  0.5%  acetic  acid  solution.  The  texture analyses  were  taken  out  at  30,  90  and  180  days  of  conservation,  and  eight  breasts  were  used  in  each  time.  The  shearing force  was