B-mode ultrasonography and ARFI elastography of articular and peri-articular structures of the hip joint in non-dysplastic and dysplastic dogs as confirmed by radiographic examination.

BACKGROUND: Canine hip dysplasia is a common orthopedic disease in veterinary practice. The diagnosis is made by radiographic examinations that evaluate bone alterations associated with hip dysplasia. Although radiographic examination is the gold standard for diagnosis, it does not allow a detailed evaluation of soft tissues such as the joint capsule and periarticular muscles. This study aimed to evaluate the accuracy of B-mode ultrasonography and acoustic radiation force impulse (ARFI) elastography in assessing the joint capsule and periarticular muscles of dogs using the Orthopedic Foundation of Animals (OFA) classification and the distraction index (DI) in the early and late diagnosis of hip dysplasia. This study sought to propose a protocol for the ultrasonographic evaluation of the structures involved in canine hip dysplasia. METHODS: Radiographic and ultrasonographic evaluations were performed on 108 hip joints of 54 dogs. Thirty dogs were older than 2 years and 24 were aged between 4 and 10 months. RESULTS: It was verified that an increase in pectineus muscle stiffness (cutoff value > 2.77 m/s) by elastography in some dysplastic dogs and an increase in the thickness of the joint capsule (cutoff value > 0.9 mm) in B-mode ultrasonography, were associated with a distraction index > 0.5, with both having a positive correlation. In B-mode ultrasonographic evaluation, the presence of signs of degenerative joint disease, such as irregularities of the cranial edge of the acetabulum and femoral head, were associated with a distraction index > 0.5 in canines, with a specificity of 94%. In adult dogs, the findings of degenerative joint disease on ultrasound were associated with a diseased OFA classification (P < 0.05). Measurement of the joint capsule > 1.10 mm was diagnostic for dysplasia in unhealthy dogs by OFA. CONCLUSIONS: ARFI elastography has shown that the pectineus muscle may experience changes in stiffness in dysplastic animals. Additionally, changes in joint capsule thickness can be identified in B-mode in young and adult dogs with dysplastic joints, which contributes to the diagnosis of hip dysplasia.

Diagnostic assessment of two-dimensional shear wave elastography in relation to dimethyl arginine levels in dogs with chronic kidney disease.

BACKGROUND: In veterinary medicine, previous studies regarding the diagnostic performance of shear wave elastography (SWE) in chronic kidney disease (CKD) are not consistent with each other. Moreover, there has been no study evaluating the relationship between symmetric dimethyl arginine (SDMA) concentration and renal shear wave velocity (SWV) using two-dimensional SWE (2D SWE) in dogs with CKD. OBJECTIVES: This study aimed to evaluate the diagnostic capability of 2D SWE in dogs with CKD and to assess the relationship between renal SWV and SDMA concentration. METHODS: Dogs with healthy kidneys and dogs with CKD underwent 2D SWE and SDMA assay. Renal stiffness was estimated as renal SWV in m/s. RESULTS: SDMA concentration had a weak positive correlation with the left (r = 0.338, p = 0.022) and right renal SWV (r = 0.337, p = 0.044). Renal SWV was not significantly different between healthy kidney and CKD groups in the left (p = 0.085) and right (p = 0.171) kidneys. CONCLUSIONS: 2D SWE may could not distinguish between dogs with healthy kidney and dogs with early stage of CKD, but it would be useful for assessing the serial change of renal function in dogs.

Shear wave velocity values measured by 2D-shear wave elastography are not different between awake and anesthetized cats without clinically significant hepatic fibrosis.

Two-dimensional shear wave elastography (2D-SWE) is widely used as a noninvasive method to quantify liver stiffness. In humans, liver stiffness approximates histologic hepatic fibrosis. While histology is the gold standard for diagnosing liver disease, 2D-SWE may be a minimally invasive alternative to biopsy in feline patients. The objectives of this prospective, observational, crossover study were trifold: (1) to assess the feasibility of performing 2D-SWE in awake cats, (2) to determine whether anesthesia altered shear wave velocity (SWV) measurements, and (3) to correlate hepatic stiffness with histologically quantified hepatic fibrosis. Eleven healthy, purpose-bred cats underwent 2D-SWE in awake and anesthetized states. SWV measurements were compared with histologic fibrosis measurements obtained from liver biopsies during the anesthetic period. The mean velocities were not significantly different between awake (1.47 ± 0.18 m/s) and anesthetized (1.47 ± 0.24 m/s) cats. Premedication and anesthetic drugs did not impact mean SWV. There was a higher variability in the SWV values in the awake group. The data points were reliably replicated, with an interquartile range of 0.24 and 0.32 in anesthetized and awake groups, respectively. There was moderate agreement between observers (intraclass correlation coefficient = 0.66). All cats had clinically insignificant fibrosis. There was no correlation between the SWV measurements and the histological fibrosis values. This study demonstrates that 2D-SWE is feasible in awake cats and that the anesthetic protocol employed did not significantly alter mean SWV. This work is the first to histologically validate normal SWV values in cats and show that 2D-SWE cannot differentiate minimal differences in feline hepatic fibrosis.

Shear wave elastography evaluation of cats with chronic kidney disease.

Chronic kidney disease (CKD) is a major health condition in cats that can lead to poor quality of life and financial implications for therapy. Currently staging and identification of CKD is limited by diagnostic testing such as creatinine and urine-specific gravity, which do not change until late in the disease course. Other methods to evaluate CKD would be valuable in the clinical setting. Shear wave elastography is one novel ultrasound method, which has shown promise in identifying increases in tissue stiffness and identifying CKD in people. As CKD is often histologically characterized by tubulointerstitial fibrosis, shear wave elastography has the potential to identify CKD and differentiate between stages of CKD in cats. This prospective observational case-control study with 78 cats found no difference in shear wave velocities between groups (P = 0.33), a contradictory finding to one prior publication. There was no effect of weight (P = 0.65), nor the presence of mineralization (P = 0.31) or infarction (P = 0.52) on cortical shear wave velocities. There was a significant effect of age on shear wave velocity (P = 0.018) where velocities increased with age. The intraclass correlation coefficient was only moderate (0.62). Possible reasons for the difference in results between our work and that published prior, include differences in methodology and differences in instrumentation. Variability in measurements in our population may be due to the effects of respiratory motion or limitations in shear wave elastography software. As such, shear wave elastography is not currently recommended as a tool to evaluate CKD in cats and further work is necessary.

Correlating two-dimensional shear wave elastography of acute pancreatitis with Spec cPL in dogs.

BACKGROUND: Pancreatitis is a common disease in which 37% of dogs had evidence of acute or chronic pancreatitis at necropsy. Although biopsy is still the gold standard to diagnose acute pancreatitis, clinical data including ultrasonographic findings and measurement of canine serum pancreatic lipase immunoreactivity (cPLI) are used in routine. However, it may be insufficient in the diagnostic approach to acute pancreatitis. OBJECTIVES: To evaluate the clinical diagnostic feasibility of two-dimensional shear wave elastography (2D SWE) on canine acute pancreatitis for enhanced diagnostic confidence. METHODS: 2D SWE was used to assess pancreatic stiffness and determine the correlation between pancreatic shear wave velocity (SWV) and Spec cPL concentration in 31 dogs with healthy pancreas and 10 dogs with acute pancreatitis. RESULTS: The pancreatic SWV was significantly higher in the acute pancreatitis group (2.67 ± 0.20 m/s) than in the healthy pancreas group (2.30 ± 0.26 m/s; p < 0.05). The moderate positive correlation was found between the pancreatic SWV and Spec cPL concentration (95% confidence interval, 0.214-0.693; r = 0.489; p < 0.05). CONCLUSIONS: These results indicated that 2D SWE was feasible for assessing pancreatic stiffness in acute pancreatitis, and that pancreatic SWV using 2D SWE correlated with Spec cPL concentration. SWE could provide a quantitative measure of pancreatic stiffness, which can increase the accuracy of diagnosing acute pancreatitis in dogs. The 2D SWE can be used as a complementary imaging modality for diagnosing acute pancreatitis in dogs.

Malignancy prediction of cutaneous and subcutaneous neoplasms in canines using B-mode ultrasonography, Doppler, and ARFI elastography.

BACKGROUND: Cutaneous and subcutaneous neoplasms are highly prevalent in dogs, ranging from benign to highly aggressive and metastatic lesions. The diagnosis is obtained through histopathology, however it is an invasive technique that may take a long time to obtain the result, delaying the beginning of the adequate treatment. Thus, there is a need for non-invasive tests that can help in the early diagnosis of this type of cancer. The aim of this study was to verify the accuracy of B-mode ultrasonography, Doppler, and ARFI elastography to predict malignancy in cutaneous and subcutaneous canine neoplasms. In addition, we aim to propose an ultrasonography evaluation protocol and perform the neoplasms characterization using these three proposed techniques. RESULTS: Twenty-one types of specific neoplasm were diagnosed, and using B-mode, we verified the association between heterogeneous echotexture, invasiveness, presence of hyperechoic spots, and cavity areas with malignancy. An increased pulsatility was verified in malignant neoplasms using Doppler (cut-off value > 0.93). When using the elastography, malignancy was associated with non-deformable tissues and shear wave velocity > 3.52 m/s. Evaluation protocols were proposed associating 4, 5, 6, or 7 malignancy predictive characteristics, and characterization was done for all tumors with at least two cases. CONCLUSIONS: We concluded that ultrasonography methods are promising and effective in predicting malignancy in these types of tumors, and the association of methods can increase the specificity of the results.

Shear wave elastography of lymph nodes in dogs with head and neck cancer: A pilot study.

Shear wave elastography (SWE) is a novel ultrasound imaging technique, used in human medicine to differentiate metastatic from non-metastatic lymph nodes (LNs) based on higher tissue stiffness. The objective of this pilot study was to evaluate whether canine metastatic LNs were stiffer compared to non-metastatic LNs. SWE of sentinel or regional LNs in dogs with head and neck cancer was performed. Ten elastograms of each LN were acquired. In each elastogram, mean, median, and maximum shear wave velocities (SWVs) were calculated in the most elastic region, the stiffest region, and the entire LN. The means of those SWVs for each region of each LN were subsequently calculated. Furthermore, a stepwise subsampling was performed to assess the effect of the number of acquired elastograms on the consistency of the classification of a LN as metastatic or not. Twenty-four LNs in 15 dogs with head and neck cancer were included, of which 10 LNs were metastatic. Metastatic medial retropharyngeal and mandibular LNs were successfully distinguished from non-metastatic LNs based on higher mean and median SWVs in the stiffest region and higher maximum SWVs in entire LNs. Furthermore, maximum SWVs in the stiffest region of mandibular LNs were higher in metastatic LNs compared to non-metastatic LNs. Downstream analyses demonstrated that at least eight elastograms were necessary to perform reliable analyses. This pilot trial demonstrated that SWE has potential to discriminate metastatic from non-metastatic LNs; however, LN status should be based on at least eight elastograms in future clinical trials.

Shear wave velocity measurements obtained in different regions are repeatable for presumed normal canine lymph nodes: A pilot study.

Shear wave elastography (SWE) has been applied as a noninvasive method for predicting regional lymph node (LN) metastases in human and veterinary patients. However, published studies describing standardized protocols and repeatability of this technique are currently lacking. The objective of this prospective, pilot, observer agreement study was to determine whether different shear wave velocity (SWV) measurements obtained in different regions of presumed normal canine LNs would be repeatable. Two imagers consecutively performed shear wave elastography of submandibular, superficial inguinal, and popliteal LNs in 10, clinically healthy adult dogs. Ten elastograms of each LN were acquired by each imager. In each adequate elastogram, three regions of interest (ROIs) were placed in the softest and stiffest region of the LN. Additionally, one ROI was drawn covering the entire LN. In each ROI, mean, median, and maximum SWVs were calculated. Mean values for the mean, median, and maximum SWVs varied from 2.33 to 3.10 m/s, 2.32 to 3.10 m/s, and 2.61 to 4.09 m/s, respectively. Intra- and interobserver agreements were acceptable. Superficial inguinal LNs demonstrated the highest intra- and interobserver agreement, followed by the popliteal and the submandibular LNs, respectively. Using the different measurements (mean, median, or maximum SWVs) had no significant effect on the intra- and interobserver variability, neither did the region (softest, stiffest, or entire LN). Findings indicated that all evaluated measurements and regions could be used to obtain reliable elastography data of presumed normal canine LNs. Clinical trials in dogs with cancer are necessary to compare SWVs of metastatic LNs with the reported SWVs and evaluate whether various measurements and regions can also be used in metastatic LNs.

Strain elastography for the assessment of skin nodules in dogs.

BACKGROUND: Strain elastography (SE) is a modern imaging technology that provides an additional way of evaluating the changes in soft tissue elasticity caused by pathophysiological processes. Despite its widespread use in human medicine, only a few studies on the application of SE in veterinary medicine are available. OBJECTIVES: To evaluate the potential usefulness of SE as an integrative imaging model in the standard ultrasound technique to better discriminate between inflammatory and neoplastic skin nodules in dogs. ANIMALS: Fifty-one client-owned dogs with clinical evidence of single or multiple skin nodules detected during routine dermatological examination. METHODS AND MATERIALS: Margins, echogenicity, echo-structure, calcification and vascularisation of 65 skin nodules were assessed with ultrasound, and SE was used to score qualitative (E-score, E-index, E2) and semiquantitative (SR) parameters. A comparison of diagnostic yields with cytological and histological findings as the gold standard was performed. RESULTS: Mast cell and benign follicular tumours showed the highest E-scores and SRs among neoplastic nodules; statistically significant differences were not detected. Calcific and nonvascularised nodules showed significantly higher E-index values than the others. Overall, a negative correlation was observed between the longitudinal diameter of skin nodules and the qualitative elastic parameters. CONCLUSIONS AND CLINICAL IMPORTANCE: In this study, SE proved to be useful to identify only a subset of nodules such as mast cells and hair follicular tumours. Although evidence supporting the use of SE in evaluating skin nodules was demonstrated to below, indicators to guide further research were developed.

Extrahepatic biliary obstruction can interfere with hepatic fibrosis prediction using two-dimensional shear wave elastography in dogs.

Two-dimensional shear wave elastography (2D-SWE) can be used to quantitatively evaluate the elastic modulus of the liver as shear wave velocity (SWV), which can noninvasively predict clinically relevant hepatic fibrosis in both dogs and humans. However, extrahepatic biliary obstruction (EHBO), regardless of the presence of clinically relevant hepatic fibrosis, can influence SWVs in humans and thus may interfere with hepatic fibrosis prediction using 2D-SWE in dogs. The aim of this prospective, observational, and one-group pretest-posttest study is to investigate whether SWV measured by 2D-SWE displays a difference between dogs with and without EHBO. A total of 20 dogs were included (7 with EHBO and 13 with gallbladder pathology but no EHBO) that underwent preoperative SWV measurement using 2D-SWE. In all dogs, stages of hepatic fibrosis were evaluated histopathologically using a scoring scheme. In addition, postoperative SWVs in dogs with EHBO relieved via laparotomy were also evaluated. The median (range) SWVs in the dogs with and without EHBO were 1.91 (1.81-2.54) m/s and 1.57 (1.37-1.64) m/s, respectively. Although there was no significant difference in the histopathological hepatic fibrosis stages between the dogs with and without EHBO, the preoperative SWVs in the dogs with EHBO were significantly higher than in dogs without EHBO (P = .0004), and SWVs were found to decrease significantly after surgery (P = .0097). This study demonstrates that EHBO can increase the SWV of dogs without clinically relevant hepatic fibrosis and can interfere with the prediction of noninvasive hepatic fibrosis using 2D-SWE.

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 ARFI elastography in the evaluation of canine prostatic alterations detected by b-mode and Doppler Ultrasonography / [Aplicabilidade da elastografia ARFI na avaliação de alterações prostáticas caninas detectadas pela ultrassonografia modo-B e Doppler]

The aim of this study was to assess the applicability of ARFI elastography for the complementary diagnosis of canine prostatic alterations. Twenty-two healthy dogs and 45 with prostatic alterations were diagnosed by the association of general and specific physical exams. Complete blood count, B-mode and Doppler ultrasound were performed. For the elastography study, tissue homogeneity and deformity were verified using the elastogram, and the shear velocities of the left and right lobes of all prostates were obtained. The change in tissue homogeneity was observed in 62.2% of the animals, while the shear speed was significantly higher in dogs with prostatic alterations, with a cut-off point > 2.35m/s as an indication of change. All animals in both groups were non-deformable. It was concluded that ARFI elastography is capable of providing qualitative and quantitative results that assist in the diagnosis of canine prostatic alterations in a non-invasive way.(AU)

O objetivo deste estudo foi avaliar a aplicabilidade da elastografia ARFI na complementação diagnóstica das alterações prostáticas em cães. Foram avaliados 22 cães saudáveis e 45 com alterações prostáticas, diagnosticadas pela associação de exames físicos geral e específico, hemograma, ultrassonografia modo B e Doppler. No estudo elastográfico, foram verificadas a homogeneidade e a deformidade tecidual, pelo elastograma, e obtidas as velocidades de cisalhamento dos lobos esquerdo e direito de todas as próstatas. A alteração de homogeneidade tecidual foi observada em 62,2% dos animais, enquanto a velocidade de cisalhamento se mostrou significativamente maior em cães com alterações prostáticas, com ponto de corte >2,35m/s como indicativo de alteração. Todos os animais de ambos os grupos se apresentaram não deformáveis. Concluiu-se que a elastografia ARFI é capaz de fornecer resultados qualitativos e quantitativos que auxiliam no diagnóstico das alterações prostáticas caninas de forma não invasiva.(AU)

Effect of Stifle Flexion Angle on the Repeatability of Real-Time Elastosonography of the Patellar Ligament in Medium- to Large-Breed Dogs.

OBJECTIVE: The aims of this study were to describe the elastosonographic findings of the patellar ligament in healthy dogs >15 kg in different positions and determine the most appropriate stifle angle to perform elastosonography of the patellar ligament. STUDY DESIGN: Eighteen clinically healthy dogs, weighing >15 kg, were prospectively recruited. B-mode ultrasound and real-time elastosonography of both patellar ligaments were performed on days 0 and 14. Elastosonography examinations were performed with the stifle in four positions: standing position, lateral recumbency with the stifle positioned at 135 degrees extension and in full passive flexion and extension. RESULTS: The percentage hardness of the patellar ligament was significantly lower when the elastosonographic examination was performed with the dog standing, compared with the other positions (p < 0.005). The variability in the elastosonography readings for each stifle position was lowest when the dog was standing (89.32%). CONCLUSION: Elastosonography is a feasible technique for evaluating the elasticity of the normal canine patellar ligament in dogs >15 kg and would be a useful technique for investigating the mechanical changes within the patellar ligament following stifle surgery. Elastosonography of the patellar ligament should be performed with the dog standing to provide the most accurate elastosonograms with lowest variability between readings.

Acoustic radiation force impulse (ARFI) elastography of the stifle joint of healthy beagles / [Elastografia acoustic radiation force impulse (ARFI) da articulação do joelho de beagles saudáveis]

The objective was to establish the reference standards for elastography of the main structures of the canine stifle joint. The medial meniscus, patellar and cruciate ligaments of thirty healthy beagles was evaluated by B-mode and ARFI elastography (n=60 joints). Analysis detected a positive correlation of the shear wave velocity (SWV) of structures according to age. Patellar ligament presented a gradual stiffness increase in relation to age, while medial meniscus and cruciate ligament were more rigid in puppies than in adults. However, greater stiffness of these structures was observed in elderly animals. Elasticity of each structure was evaluated according to gender and reproductive status. Females presented greater stiffness of all structures, with SWV differing 0.3 and 0.36m/s between genders. Only the medial meniscus was not stiffer in neutered animals when compared to intact animals, differing only 0.02m/s in menisci and 0.4 to 0.47m/s in ligaments between groups. These findings corroborate with literature data that states a higher prevalence of ligament insufficiency in elderly dogs, females and neutered animals. It was concluded that ARFI elastography of the canine stifle joint is feasible and its application can be potentially effective in early diagnosis of ligament and meniscal changes.(AU)

O objetivo foi estabelecer os padrões normais para elastografia das principais estruturas da articulação do joelho em cães. O menisco medial, ligamento patelar e cruzado de trinta beagles saudáveis foram avaliados pelo modo B e elastografia ARFI (n=60 articulações). A análise detectou uma correlação positiva da velocidade de cisalhamento (SWV) das estruturas com a idade. O ligamento patelar apresentou um aumento gradual da rigidez em relação à idade, enquanto o menisco medial e o ligamento cruzado foram mais rígidos em filhotes do que em adultos. Entretanto, observou-se maior rigidez dessas estruturas em idosos. A elasticidade de cada estrutura foi avaliada de acordo com o sexo e o estado reprodutivo. As fêmeas apresentaram maior rigidez em todas as estruturas, com SWV diferente de 0,3 e 0,36m/s entre os sexos. Somente o menisco medial não foi mais rígido nos animais castrados quando comparado não castrados, diferindo apenas 0,02m/s no menisco e 0,4 a 0,47m/s nos ligamentos entre os grupos. Esses achados corroboram com dados da literatura que afirmam maior prevalência de insuficiência ligamentar em cães idosos, fêmeas e animais castrados. Concluiu-se que a elastografia ARFI da articulação do joelho canino é viável e sua aplicação pode ser eficaz no diagnóstico precoce de alterações ligamentares e meniscais.(AU)

Acoustic Radiation Force Impulse (ARFI) elastography imaging of equine distal forelimb flexor structures / [Elastografia Acoustic Radiation Force Impulse (ARFI) das estruturas flexoras da porção distal do membro torácico de equinos]

This study set out to determine normal values for acoustic radiation force impulse (ARFI) elastography of the superficial digital flexor tendon, deep digital flexor tendon, accessory ligament of the deep digital flexor tendon and suspensory ligament in horses. Twenty-four horses were submitted to conventional sonographic assessment and elastography imaging (quantitative ARFI method) of distal forelimb tendons and ligaments at nine anatomical regions. Elastograms depicted tendons and ligaments in orange to red tones consistent with greater stiffness. Shear wave velocity was higher in the longitudinal compared to the cross-sectional plane but did not differ significantly between the left and right forelimbs. The suspensory ligament was stiffer compared to remaining structures in the cross-sectional plane. Ligaments were stiffer than tendons and the deep digital flexor tendon was stiffer than the superficial digital flexor tendon in the longitudinal plane. Target structures were stiffer in male compared to female horses and stiffness tended to increase with age. ARFI elastography proved to be a feasible and reproducible imaging modality for assessment of distal forelimb tendons and ligaments in horses. Qualitative features derived from stiffness quantification in these structures can be applied to horses with musculoskeletal disorders, as well as to other animal species.(AU)

Este trabalho objetivou estabelecer valores de referência por meio da elastografia ARFI ("Acoustic Radiation Force Impulse") do tendão flexor digital superficial, tendão flexor digital profundo, ligamento acessório inferior e ligamento suspensor do boleto em equinos hígidos. Vinte e quatro equinos foram submetidos aos exames ultrassonográfico e elastográfico (método ARFI quantitativo) dos tendões e ligamentos da porção distal do membro torácico, em nove regiões anatômicas diferentes. Os elastogramas mostraram tendões e ligamentos de coloração alaranjada a vermelha, que representam maior rigidez. Não houve diferenças em relação ao membro avaliado; as velocidades de cisalhamento foram maiores nos planos longitudinais. No plano transversal, os ligamentos suspensores foram mais rígidos em comparação aos demais. No plano longitudinal, os ligamentos mostraram-se mais rígidos que os tendões, e o tendão flexor digital profundo, mais rígido que o tendão flexor digital superficial. As estruturas mostraram-se mais rígidas nos machos, e houve uma tendência à maior rigidez em animais mais velhos. A elastografia ARFI comprovou ser um método viável e reprodutível para avaliação dos tendões e ligamentos dos membros torácicos de equinos. As características qualitativas obtidas a partir da rigidez dessas estruturas podem ser utilizadas para testes em equinos com distúrbios musculoesqueléticos e também em outras espécies animais.(AU)

Contrast-enhanced ultrasound sonography combined with strain elastography to evaluate mandibular lymph nodes in clinically healthy dogs and those with head and neck tumors.

Determining lymph node metastases in dogs with neoplasia is important in staging and developing a therapeutic plan. In this study, the clinical efficacy of combined lymphosonography and strain elastography was evaluated for its ability to identify metastatic mandibular lymph nodes. Data from clinically healthy dogs (n = 16) and those with head/neck tumors (n = 11) were enrolled. Strain elastographic patterns were classified according to the percentage of the stiffness lymph node area (grade 1-4/4). Lymphosonographic images were evaluated quantitatively (visualization of lymphatic vessels/lymph nodes; contrast transit time) and qualitatively (enhancement pattern). There was a significant difference in the strain elastographic pattern (P = 0.011) and lymphosonographic contrast enhancement (P = 0.001) in the metastatic nodes compared to clinical healthy or non-metastatic nodes. Mandibular lymph nodes with filling defects after lymphosonography and high-grade strain elastographic patterns suggested metastasis, and the combination of lymphosonography and strain elastography was useful for identifying malignancy.

Renal ultrasonographic strain elastography and symmetric dimethylarginine (SDMA) in canine and feline chronic kidney disease.

Chronic kidney disease (CKD) is a common renal disease in dogs and cats. Renal fibrosis is a main pathologic process leading of CKD progression. Renal biopsy is the gold standard for renal fibrosis assessment. However, it is not routinely performed in clinic due to its invasiveness. Therefore, the aim of this study was to evaluate the use of ultrasonographic strain elastography (SE), which is a non-invasive method for renal tissue stiffness determination and its association with renal function. Renal strain ratios and renal function were evaluated in 13 CKD dogs (CKDD), 38 healthy dogs (HD), 17 CKD cats (CKDC) and 26 healthy cats (HC). There were significantly lower renal cortical strain ratios than medullary strain ratios in all groups (HD; P<0.01, HC; P<0.01, CKDD and CKDC; P<0.05) and significantly lower cortical and medullary strain ratios in both CKDD and CKDC than in healthy control animals of both species (P<0.0001). In dogs, the renal cortical and medullary strain ratios significantly negatively correlated with plasma creatinine (P<0.05), blood urea nitrogen (BUN; P<0.05; P<0.01, respectively), and symmetric dimethylarginine (SDMA; P<0.01). In cats, similar correlations were found for plasma creatinine (P<0.001), BUN (P<0.05; P<0.001, respectively) and SDMA (P<0.05). SE might be a promising imaging diagnostic tool for renal-elasticity evaluation, also correlating with renal functional impairment in canine and feline CKD.

Quantitative ultrasound elastography and biometry of the bitch uterus in the early puerperium after vaginal delivery and caesarean section.

Elastography is an actual imaging method used to qualitatively and quantitatively evaluate the elastic properties of tissues. The aim of this study was to evaluate and compare uterine tissue biometry and stiffness during post-partum period in brachycephalic bitches (n = 12) after c-section (GCS; n = 8) or normal delivery (GNB; n = 4). These animals were evaluated daily by abdominal ultrasound from the day of delivery until the 10th day post-partum; measuring uterine diameter, myometrial and endometrial thickness (mm) and shear wave velocity (SWV; m/s), by B-mode and ARFI (acoustic radiation force impulse) elastography, respectively. Uterine diameter was higher (p = .012) in animals submitted to c-section (15.26 ± 4.73 mm) than in normal birth (12.53 ± 2.64 mm) during the first 7 days post-partum. Uterine thickness gradually involuted in both groups (p < .0001), the myometrium during the first 9 days (p = .005) and the endometrium during the first 6 days (p = .003). The myometrial and endometrial SWVs were similar between types of delivery (p = .7846 and .8273) and presented a gradual increase (p = .411; .0043, respectively), during the first 10 days post-partum. It was concluded that bitches with normal delivery had smaller uterine thickness and faster puerperal involution than submitted to c-section, while uterine tissue stiffness was similar between delivery types and increased gradually during post-partum.

Semi-quantitative strain elastography may facilitate pre-surgical prediction of mandibular lymph nodes malignancy in dogs.

Evaluation of mandibular lymph nodes in a patient with head and neck cancer is important for stage determination and prognosis development, and, in human medicine, the use of sonoelastography for differentiating between non-metastatic and metastatic lymph nodes has been reported. Our prospective, cross-sectional study aimed to evaluate the diagnostic performance of strain elastography and to determine elastographic cut-off values for predicting malignancy. Sixty-six mandibular lymph nodes were included (clinical healthy, n = 45; non-metastatic, n = 8; and metastatic, n = 13). Elastographic images were evaluated qualitatively (elastographic pattern) and semi-quantitatively (mean hue histogram and stiffness area ratios). Elastographic patterns were classified as grades 1 to 4, according to the percentage of high elasticity determined by visualization. The mean hue histogram was defined based on as the mean pixel color values within the lymph node. Stiffness area ratios were determined by computer program analysis of the stiff area. Among the criteria, receiver operating characteristic curve analyses revealed cut-off values for the prediction of malignancy of 92.26 for mean hue histogram (sensitivity: 100%, specificity: 92%), and 0.17 for stiffness area ratios (sensitivity: 86%, specificity of 100%). Reproducibility and repeatability were excellent. In conclusion, semi-quantitative evaluation via strain elastography holds potential for predicting lymph node malignancy.

Usefulness of noninvasive shear wave elastography for the assessment of hepatic fibrosis in dogs with hepatic disease.

BACKGROUND: Two-dimensional shear wave elastography (2D-SWE) can noninvasively evaluate hepatic elastic modulus as shear wave velocity (SWV). Additionally, it may predict the presence of clinical relevant hepatic fibrosis (≥F2) in dogs with hepatic disease. OBJECTIVES: To investigate whether SWV measured by 2D-SWE can differentiate between dogs with (≥F2) and without (F0-1) clinically relevant hepatic fibrosis. ANIMALS: Twenty-eight client-owned dogs with hepatic disease and 8 normal healthy Beagle dogs were enrolled. METHODS: In this cross-sectional prospective study, SWVs were measured using 2D-SWE in all dogs. Hepatic fibrosis stages and necroinflammatory activity grades were histopathologically evaluated using a histological scoring scheme that was adapted from the Ishak schema used in human medicine. RESULTS: Median SWVs were significantly higher in dogs with clinically relevant hepatic fibrosis (2.04 m/s; range, 1.81-2.26 m/s) than in healthy dogs (1.51 m/s; range, 1.44-1.66 m/s; P = .007), and dogs without clinically relevant hepatic fibrosis (1.56 m/s; range, 1.37-1.67 m/s; P < .001). However, no significant difference was found in the SWVs between dogs without clinically relevant hepatic fibrosis and healthy dogs (P = .99). Furthermore, median SWVs were not significantly different among dogs with necroinflammatory activity, those without necroinflammatory activity, and healthy dogs (Kruskal-Wallis test, P = .12). CONCLUSIONS AND CLINICAL IMPORTANCE: The 2D-SWE may be useful for predicting the presence of hepatic fibrosis in dogs with hepatic disease.