CT features of feline lipiduria and renal cortical lipid deposition.

OBJECTIVES: The aims of this study were to document the presence and prevalence of feline lipiduria and renal lipid deposition on CT, and to search for associations between the presence of lipiduria and sex, urinary tract abnormalities and urolithiasis. METHODS: The CT examinations of 252 cats were reviewed for the presence of an antigravitational hypodense bubble in the urinary bladder with density values between -180 Hounsfield units (HU) and -20 HU. To identify associations between lipiduria and sex, urinary tract abnormalities and urolithiasis, Fisher's exact test was used. Renal cortical density measurement was performed in all cats. The Mann-Whitney test was performed to compare renal cortical density between lipiduric and unaffected cats. RESULTS: A total of 27 domestic cats (10.7%) had CT evidence of lipiduria. Lipiduric cats had a significantly lower renal cortical density than unaffected cats (P <0.01). Male neutered cats had a significantly higher frequency of lipiduria and lower renal cortical density compared with female neutered cats (P <0.01). There was no significant difference between the groups regarding renal, ureteral or urethral abnormalities. CONCLUSIONS AND RELEVANCE: Lipiduria is a common physiological phenomenon in cats that can be detected on routine CT examinations. Decreased renal cortical density is associated with lipiduria. This may aid in the diagnosis of feline lipiduria and help to differentiate its presence from other pathological depositions and excretions.

TOMOGRAPHIC ATTENUATION OF THE HEPATIC PARENCHYMA OF ADULT FREE-RANGING AND CAPTIVE BOAS (BOA CONSTRICTOR).

Improperly managed care conditions for reptiles can lead to clinical problems, including those of nutritional origin. A diagnostic tool to aid in the assessment of hepatic lipidosis is warranted. Evaluation of attenuation using quantitative computed tomography has a variety of indications in animals and permits the standardization of hepatic computed tomography (CT) reference values, aiding in the diagnosis of lipidosis. The objective of this paper was to estimate hepatic quantitative CT reference values for boas because of the lack of data in the literature for this species. CT scans were performed in 13 boas (Boa constrictor constrictor): 5 under managed care and 8 that were free ranging. Results show that the mean hepatic attenuation in the captive boa group was well below the mean for the free-ranging animals (P < 0.05) with respective values of 48.78 ± 6.57 and 61.76 ± 7.11 HU. These results suggest an influence of managed care on liver attenuation. These results were observed despite the lack of clinical or laboratory changes. This imaging technique is useful to detect early hepatic changes; however, clinical relevance is unknown at this point. Further studies and standardization of species-specific values for hepatic quantitative CT would contribute to better understanding of the physiologic, physiopathologic, environmental, and nutritional processes.

OSTEODENSITOMETRY AND TOMOGRAPHIC FINDINGS IN FOUR CAPTIVE GIANT SOUTH AMERICAN TURTLES (PODOCNEMIS EXPANSA) WITH METABOLIC BONE DISEASE.

Giant South American turtles (Podocnemis expansa) are at a risk of extinction because of the rapid decline in their population over the last few decades. Metabolic bone disease (MBD) is common in captive testudines, but is often not diagnosed until a later stage. The authors present the cases of four captive giant South American turtles with carapace deformity secondary to MBD that underwent computed tomography (CT) scans of the carapace bones and vertebral column. Findings indicative of changes in geometry were found in both. The cancellous bone pattern was characterized by varying degrees of increased trabecular spacing and cortical thinning of the pleural bones. Bone densitometry analysis of the pleural and neural bones and at the level of the body of the third, fourth, and fifth dorsal vertebrae showed mean density values much lower than those found in two adult specimens of the same species that were considered healthy. In conclusion, CT contributed important information on the degree of demineralization and possible structural changes due to MBD and should be considered a relevant tool for diagnosis of this condition.

Determination of baseline values for routine ophthalmic tests in bearded capuchin (Sapajus libidinosus).

BACKGROUND: Establish baseline values for ophthalmic diagnostic tests in Sapajus libidinosus. METHODS: Ophthalmic diagnostic tests, namely Schirmer tear test 1 (STT-1), intraocular pressure (IOP), B-mode ultrasound, culture of the bacterial conjunctival microbiota, and conjunctival exfoliative cytology, were performed in 15 S. libidinosus. RESULTS: Mean values found were as follows: 2.50 ± 2.94 mm/min for the STT-1; 13.3 ± 3.32 mm Hg for the IOP; 2.47 ± 0.41 mm for the depth of the anterior chamber; 2.86 ± 0.96 mm for the axial length of the lens; 10.97 ± 0.48 mm for the depth of the vitreous chamber; and 16.32 ± 1.24 mm for the axial length of the eyeball. The bacterial genus most frequently found was Staphylococcus spp. Conjunctival cytology showed intermediate epithelial, squamous superficial epithelial, and keratinized cells. CONCLUSIONS: Determination of baseline values for eye measurements and ophthalmic tests will assist in the diagnosis of eye diseases in S. libidinosus monkeys.

QUANTITATIVE COMPUTED TOMOGRAPHY OF HEALTHY ADULT BOAS ( BOA CONSTRICTOR).

The evaluation of radiodensity using quantitative computed tomography (QCT) has several indications in animals. It allows for standardization of reference values for bone densitometry and helps in the clinical diagnosis of diseases. Currently, there is a lack of such data in the literature for Boa constrictor constrictor. Therefore, the objective of this study was to estimate reference values for bone density in boas ( Boa constrictor constrictor). Computed tomography scans were performed on 10 adult, healthy, free-ranging boas. Results showed mean values of vertebral trabecular bone for free-ranging boas were 1,237.91 ± 54.61 mg/cm3. Because of the difficulty in obtaining clinical and radiographic diagnoses of metabolic bone diseases, especially in a timely manner, densitometry may become a helpful tool in preventive veterinary medicine.

Development of a finite element model of the ligamentous cervical vertebral column of a Great Dane.

Cervical spondylomyelopathy (CSM), also known as wobbler syndrome, affects mainly large and giant-breed dogs, causing compression of the cervical spinal cord and/or nerve roots. Structural and dynamic components seem to play a role in the development of CSM; however, pathogenesis is not yet fully understood. Finite element models have been used for years in human medicine to study the dynamic behavior of structures, but it has been mostly overlooked in veterinary studies. To our knowledge, no specific ligamentous spine models have been developed to investigate naturally occurring canine myelopathies and possible surgical treatments. The goal of this study was to develop a finite element model (FEM) of the C2-C7 segment of the ligamentous cervical vertebral column of a neurologically normal Great Dane without imaging changes. The FEM of the intact C2-C7 cervical vertebral column had a total of 188,906 elements (175,715 tetra elements and 12,740 hexa elements). The range of motion (in degrees) for the FEM subjected to a moment of 2Nm was approximately 27.94 in flexion, 25.86 in extension, 24.14 in left lateral bending, 25.27 in right lateral bending, 17.44 in left axial rotation, and 16.72 in right axial rotation. We constructed a ligamentous FEM of the C2-C7 vertebral column of a Great Dane dog, which can serve as a platform to be modified and adapted for studies related to biomechanics of the cervical vertebral column and to further improve studies on osseous-associated cervical spondylomyelopathy.

USE OF COMPUTED TOMOGRAPHY FOR INVESTIGATION OF HEPATIC LIPIDOSIS IN CAPTIVE CHELONOIDIS CARBONARIA (SPIX, 1824).

Computed tomography is a sensitive and highly applicable technique for determining the degree of radiographic attenuation of the hepatic parenchyma. Radiodensity measurements of the liver can help in the diagnosis of hepatic lipidosis in humans and animals. The objective was to investigate the presence of hepatic lipidosis in captive red-footed tortoises (Chelonoidis carbonaria) using computed tomography. Computed tomography was performed in 10 male red-footed tortoises. Mean radiographic attenuation values for the hepatic parenchyma were 11.2±3.0 Hounsfield units (HU). Seven red-footed tortoises had values lower than 20 HU, which is compatible with C. carbonaria hepatic lipidosis. These results allowed an early diagnosis of the hepatic changes and suggested corrective measures regarding feeding and management protocols.

Creatine kinase serum activity in feline hyperthyroidism / Atividade sérica da creatinina quinase no hipertireoidismo felino

The aim of this study is to determine the occurrence of creatine kinase (CK) serum activity in cats with hyperthyroidism and its associations with clinical-pathological alterations and with total (TT4) and free (FT4) thyroxin. CK serum activity was evaluated in 19 cats with spontaneous hyperthyroidism, with TT4 ranging from 34.88-294.98nmol L-1 and FT4 ranging from 2.83-52.9pmol L-1 and also by serum biochemical analysis, including the activity of CK, alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), cholesterol and bile acids. The reference value for CK considered in this study was of 110-250U L-1. CK serum activity was evaluated in 19 cats with spontaneous hyperthyroidism, with TT4 ranging from 34.88-294.98nmol L-1 and FT4 ranging from 2.83-52. 9pmol L-1. Its activity CK was elevated in 47.3% of cats (≥250U L-1) and presented statistical difference (P<0.05) between cats with or without cardiac disease. CK presented weak association with all parameters in biochemical analysis. In this study, it was not possible to establish a clear association between hyperthyroidism and the increase of CK. However, it is important to highlight the inclusion of CK activity in the routine examinations for the evaluation of hyperthyroidism and for further studies to be developed.

O hipertireoidismo é uma doença endócrina comum em gatos, resultante da excessiva secreção dos hormônios tireoidianos (tiroxina-T4 e triiodotironina-T3), possui caráter multissistemico e provoca várias alterações nos parametros bioquímicos. A creatina quinase (CK) é uma enzima que tem sua atividade sérica aumentada em diversas enfermidades e, na medicina veterinária, é principalmente utilizada para avaliar lesões no músculo esquelético, músculo cardíaco e tecido hepático. O objetivo deste estudo foi determinar a ocorrência da atividade sérica da CK em gatos com hipertireoidismo e suas associações com alterações clínico-patológicas e com a tiroxina total (TT4) e livre (FT4). A atividade sérica da CK foi avaliada em 19 gatos com hipertireodismo espontâneo, com TT4 variando de 34,88-294,98nmol L-1 e FT4 variando de 2,83-52,9nmol L-1. Sua atividade estava elevada em 47,3% dos gatos (≥250U L-1) e apresentou diferença estatística (P<0,05) entre gatos com ou sem doença cardíaca. A CK apresentou associação fraca com os paramêtros bioquímicos avaliados. Neste estudo, não foi possível estabelecer uma associação clara entre o hipertireoidismo e o aumento da CK. Contudo, os resultados encontrados da atividade da CK encorajam a realização de novos estudos, para uma compreensão mais profunda da elevação da CK no hipertireoidismo.

Quantitative computed tomography of the liver in juvenile green sea turtles (Chelonia mydas).

Quantitative computed tomography (QCT) is a highly sensitive, applicable technique for determining the x-ray attenuation of organs. This technique reveals great precision in the detection of alterations in the x-ray attenuation of hepatic parenchyma, although the lack of studies establishing normal values limits its application in wild animals. The objective of this study was to establish mean hepatic attenuation values in four healthy juvenile sea turtles (Chelonia mydas) using QCT. Helical computed tomography scans were performed and regions of interest selected in the liver after multi-planar reconstruction images were obtained. The mean attenuation value for the hepatic parenchyma in these four turtles was 60.09 +/- 5.3 standard deviation Hounsfield units. Determining normal x-ray attenuation values of the liver increases knowledge of the computed tomographic anatomy of this species and may be useful in the investigation of hepatic diseases.

Densitometria da vértebra dorsal, osso pleural e osso neural em tartarugas verdes hígidas por tomografia computadorizada quantitativa / Densitometry of dorsal vertebrae, pleural bone and neural bone in healthy green sea turtles by quantitative computed tomography

A tomografia computadorizada quantitativa (TCQ) é uma técnica com alta sensibilidade, aplicabilidade e precisão no diagnóstico de perda de massa óssea, entretanto a falta de valores de normalidade para animais silvestres limita a sua aplicação clínica. O presente estudo objetiva estabelecer valores médios de radiodensidade do osso trabecular das vértebras dorsais, osso pleural e osso neural de tartarugas marinhas juvenis hígidas utilizando a TCQ. Para isso, utilizou-se um grupo experimental de cinco animais que foram submetidos a exames de tomografia computadorizada helicoidal, sendo as mensurações da radiodensidade óssea realizadas ao nível da terceira, quarta e quinta vértebras dorsais. Os valores médios de radiodensidade do osso trabecular das vértebras dorsais, osso pleural e osso neural foram, respectivamente, de 287,4±39,1, 1093,74±100,4 e 1089,6±86,5 unidades Hounsfield (HU). Estudos complementares devem ser realizados em diferentes espécies e faixas etárias de quelônios para favorecer a aplicação clínica desta técnica.

Quantitative computed tomography (QCT) is a technique with high sensitivity, applicability and accuracy in the diagnosis of bone loss; however the lack of normal values for wild animals limits their clinical application. This study aims to establish medium values radiodensity trabecular bone of the dorsal vertebrae, bone pleural and neural bone in healthy juvenile sea turtles using the QTC. For this we used an experimental group of five animals that underwent helical computed tomography, and measurements of bone radiodensity conducted at the level of the third, fourth and fifth dorsal vertebrae. The medium values of radiodensity trabecular bone of the dorsal vertebrae, pleural bone, and neural bone were respectively 287.4±39.1, 1093.74±100.4, and 1089.6±86.5 Hounsfield units (HU). Further studies should be performed in different species and ages of turtles to encourage the clinical application of this technique.

Pulsed-wave tissue Doppler imaging of the myocardium of cats with induced thyrotoxicosis / Doppler tecidual pulsado do miocárdio de gatos com tirotoxicose induzida

Left ventricular myocardial motion was quantified using pulsed-wave tissue Doppler imaging (PW-TDI) in nine adult cats before and after thyrotoxicosis induction. In order to induce thyrotoxicosis, all cats were given 150µg kg-1 of levothyroxine sodium as a single oral dose each day for 10 weeks. PW-TDI examinations were performed immediately before the induction and by the end of the experimental protocol. An increase in myocardial motion velocity was documented at the interventricular septum level, demonstrated by an elevation in systolic (Sa), and early (Ea) and late (Aa) diastolic waves (P<0.05). However, no alteration in Sa, Ea and Aa values was seen at the lateral mitral annulus. Heart rate increased significantly between the experimental stages, and three of the animals presented fused Ea and Aa waves at the end of the experiment. The experimental protocol used in this study caused alterations in left ventricular myocardial motion velocity, but did not impair left ventricular diastolic function.

A velocidade de movimentação miocárdica do ventrículo esquerdo foi quantificada por meio de exames ecocardiográficos com Doppler tecidual pulsado (PW-TDI) em nove gatos adultos antes e após indução à tirotoxicose. Para indução da tirotoxicose, todos os gatos receberam doses diárias de 150mg kg-1 de levotiroxina sódica, por via oral, durante 10 semanas. Os exames de PW-TDI foram realizados imediatamente antes da indução e ao final do protocolo experimental. Uma elevação na velocidade de movimentação miocárdica foi documentada ao nível do septo interventricular, demonstrado por um aumento das ondas sistólica (Sa) e diastólicas (Ea e Aa; P<0,05). No entanto, nenhuma alteração nos valores de Sa, Ea e Aa foi encontrada ao nível da parede livre do ventrículo esquerdo. A frequência cardíaca aumentou significativamente entre os momentos experimentais, sendo que três animais apresentaram fusão das ondas Aa e Ea ao final do experimento. O protocolo experimental utilizado neste estudo causou alterações na velocidade de movimentação do miocárdio ventricular esquerdo, mas sem causar danos à função diastólica do ventrículo esquerdo.

Radiografia quantitativa hepática de cães tranquilizados com acepromazina / Hepatic quantitative radiography in dogs with acepromazine

O maleato de acepromazina é um dos tranquilizantes mais utilizados em medicina veterinária, podendo causar esplenomegalia, mas não é conhecida a possibilidade de ocorrência de hepatomegalia. Objetivou-se, com o presente estudo, utilizar a radiografia quantitativa com auxilio digital para determinar o tamanho e volume do fígado de cães tranquilizados com acepromazina. Foram radiografados, na projeção lateral direita e ventrodorsal do fígado, nove cães hígidos, antes e após a administração intramuscular de maleato de acepromazina, na dose de 0,1mg kg-1 de peso. Foi possível caracterizar aumento das dimensões hepáticas (P<0,05) entre os diferentes momentos experimentais com forte correlação positiva entre as medidas corpóreas. A técnica radiográfica quantitativa empregada neste estudo caracterizou com precisão o aumento de tamanho e volume hepático nos cães tratados com acepromazina.

The acepromazine is one of the most commonly tranquilizer used in veterinary medicine and its use may cause splenomegaly. However it is not known if it can cause hepatomegaly. The aim of this study is to evaluate the quantitative radiography with digital assistance to determine the liver size and volume of dogs tranquilized with acepromazine. Nine healthy dogs were radiographed in the lateral right and ventral-dorsal liver , before and after intramuscular administration of acepromazine at a dose of 0.1kg-1. It was possible to characterize the size and increase in liver size (P<0.05) between the different experimental moments with a strong positive correlation between the measures liver assets. The quantitative radiographic technique used in this study accurately characterized the increase in size and volume of the liver in dogs treated with acepromazine.

Grau de desmineralização em osso trabecular e cortical por meio de tomografia computadorizada quantitativa em cães submetidos à terapia com prednisona / Trabecular and cortical bone demineralization degree by quantitative computed tomography in dogs treated with prednisone

Os glicocorticóides são fármacos amplamente utilizados na medicina veterinária, entretanto, além dos efeitos benéficos, o seu emprego pode desencadear uma série de efeitos indesejados. Foi realizado um ensaio clínico em oito cães hígidos com o intuito de avaliar possíveis alterações na densidade mineral óssea após a terapia com prednisona, utilizando a tomografia computadorizada helicoidal. Todos os animais receberam a prednisona via oral na dose diária de 2mg kg-1 de peso durante 30 dias. A densidade mineral óssea foi determinada a partir da obtenção de valores de radiodensidade da região de osso cortical e osso trabecular do corpo vertebral da segunda vértebra lombar, imediatamente antes e após o período de administração do medicamento. O protocolo experimental permitiu a caracterização de significativa (P<0,05) diminuição da radiodensidade do corpo vertebral da segunda vértebra lombar, entretanto não se constatou desmineralização significativa na região cortical. Nenhum dos animais apresentou fratura patológica ao término da administração do medicamento. O presente estudo comprovou que as alterações no metabolismo ósseo de cães submetidos à terapia com prednisona na dose de 2mg kg-1 ocorrem precocemente somente em osso trabecular, tornando-se recomendado um monitoramento dos pacientes para prevenção de fraturas patológicas.

Glucocorticoids are widely used in veterinary medicine. However, beyond the beneficial effects, their use can trigger a series of unwanted effects. A clinical trial was conducted in eight healthy dogs in order to assess possible changes in bone mineral density after therapy with prednisone using helical computed tomography. All animals received oral prednisone at a daily dose of 2mg kg-1 of body weight for 30 days. Bone mineral density was determined by the obtaining of radiodensity values from the cortical region and the trabecular region of the second lumbar vertebra immediately before and after the period of drug administration. The experimental protocol allowed the characterization of a significant (P<0.01) decrease of trabecular bone radiodensity on the second lumbar vertebra, but no significant demineralization was found in the cortical region. None of the dogs used in this experiment had pathological fracture at the end of the experimental protocol. This study showed that in dogs subjected to therapy with prednisone at a dose of 2mg kg-1 changes in bone metabolism occur early in trabecular bone, being recommended to monitor these patients for the prevention of pathologic fractures.

Marcadores do metabolismo ósseo em gatos / Bone metabolism markers in cats

A formação e reabsorção óssea são processos contínuos no organismo e uma das maneiras de avaliar as alterações, a intensidade ou alterações desse processo é pela mensuração dos marcadores do metabolismo ósseo no soro ou na urina. Os objetivos deste estudo foram identificar se os testes comerciais para detectar osteocalcina (OC), peptídeo aminoterminal do procolágeno tipo I (PINP) e telopeptídeo carboxiterminal do colágeno tipo I (ICTP) em seres humanos podem ser utilizados em gatos; e mensurar os valores de OC, PINP e ICTP e correlacioná-los com a densitometria mineral óssea (DMO) em gatos adultos jovens. As médias das concentrações séricas da OC e do ICTP obtidas foram, respectivamente, 0,15±0,03ng mL-1 e 8,59±5,78ng mL-1. A média (±DP) da DMO apresentada foi 1,40±0,23mmAl. Os marcadores do metabolismo ósseo apresentaram baixa correlação entre si e com a DMO. Este estudo concluiu que o teste comercial para mensuração da OC e ICTP em seres humanos podem ser utilizados em gatos, e o teste comercial para mensuração do PINP em seres humano não é viável para essa espécie.

Bone formation and resorption are continuous processes and a tool to evaluate alterations these activities is to measure seric or urinary markers of bone metabolism. The aims of this study were to identify if commercial sets available to detect human osteocalcin, (OC) amino-terminal propeptides of procollagen type I (PINP), type-I collagen carboxi-terminal telopeptide (ICTP) are also available for usage in domestic cats; measure seric levels of OC, PINP and ICTP; correlate findings with bone mineral density (BMD) in young adult cats. OC and ICTP means (±SD) was 0.15±0.03ng mL-1 and 8.59±5.78ng mL-1, respectively. BMD while 1.40±0.23mm Al. Bone metabolism markers showed low correlation between then and also BMD. This paper concludes that commercial sets designed for OC and ICTP measures in humans may be used for same purpose in cats to evaluate bone metabolism activity alterations and that kits used for PINP in human should not be used to evaluate in cats.

Avaliação ecocardiográfica de gatos com tirotoxicose induzida / Echocardiographic evaluation of cats with induced thyrotoxicosis

O hipertiroidismo é uma doença multissistêmica caracterizada pela elevação dos níveis séricos dos hormônios tireoidianos, sendo uma endocrinopatia comum em gatos. O objetivo deste trabalho foi avaliar possíveis alterações cardíacas pelo exame ecocardiográfico em gatos com tirotoxicose induzida. Foram utilizados nove gatos adultos, sem distinção de sexo ou raça e sem alterações que pudessem interferir nos resultados do estudo. Para indução à tirotoxicose, foram administrados, por via oral, comprimidos, na dose de 150µg kg-1 de levotiroxina sódica, a cada 24 horas, durante 70 dias. Os exames foram realizados em dois momentos: um momento antes da indução e outro ao término do protocolo experimental. Dos parâmetros avaliados, foi observada diminuição estatisticamente significativa nos valores de diâmetro interno do ventrículo esquerdo, tanto na sístole, quanto na diástole. O diâmetro diastólico (DDVE) médio nos animais variou de 14,97mm, no momento inicial, para 13,27mm, no momento final. Os valores médios do diâmetro sistólico (DSVE) variaram de 8,92mm para 7,92mm, nos momentos inicial e final, respectivamente. Os outros parâmetros avaliados não sofreram alterações. Dessa forma, já foi possível caracterizar alterações cardiovasculares secundárias ao excesso dos hormônios tiroidianos nesse curto prazo de indução, porém não havendo a instalação de um quadro de insuficiência cardíaca congestiva. Ressalta-se a necessidade de um diagnóstico precoce do hipertiroidismo felino para evitar a evolução dos efeitos cardiovasculares dessa enfermidade.

Hyperthyroidism is a multisystemic disease arising from the excessive serum levels of the thyroid hormones, being a common endocrinopathy in cats. This study aimed at the evaluation of possible cardiac abnormalities by the echocardiographic exam in cats with induced thyrotoxicosis. Nine adult cats, regardless of sex or race and without alterations that could interfere in the study results, were used. To induce the thyrotoxicosis, levothyroxine sodium oral tablets in doses of 150µg kg-1 every 24 hours over 70 days were administered. The examinations were conducted in two stages: a time before induction, and another at the end of the experimental protocol. It was observed a statistically significant decrease in left ventricle internal diameter during systole and diastole. The others evaluated parameters didn't suffer any alteration. The mean value of the left ventricle diastolic diameter (LVDD) was 14.97mm in the initial moment, and 13.27mm in the final moment. The mean values of the left ventricle systolic diameter (LVSD) were 8.92mm and 7.92mm at the initial and final moments respectively. The others evaluated parameters didn't suffer any alteration. Thus, it was possible to characterize cardiovascular changes secondary to the excess of thyroid hormones in this short period of induction, but none of the cats presented congestive heart failure. It is emphasized the need for an early diagnosis of the feline hyperthyroidism, in order to prevent the development of cardiovascular effects of this disease.

Radiodensidade hepática de cães hígidos por tomografia computadorizada helicoidal / Hepatic radiodensity in healthy dogs by helical computed tomography

Os objetivos do presente estudo são obter valores médios de radiodensidade do parênquima hepático de cães normais e descrever a adaptação na espécie canina de uma técnica de mensuração da densidade tomográfica já utilizada em humanos. Para a realização do estudo, foram adquiridos exames tomográficos do fígado de oito cães hígidos adultos jovens, sem distinção de sexo ou raça. Após a realização do exame, foram obtidos valores médios de radiodensidade de três regiões de interesse (ROIs) do parênquima hepático em três diferentes níveis de corte. Além disso, foi realizada a análise de uma região de interesse do parênquima esplênico em três diferentes níveis de corte para uma avaliação comparativa entre os órgãos. Observou-se, no grupo avaliado, um valor médio de atenuação HU de 59,58±3,34 unidades Hounsfield (HU). A diferença de densidade entre o parênquima hepático e o esplênico foi, em média, de 4,69±7,77HU. No presente estudo, o exame de tomografia computadorizada demonstrou ser uma técnica com alta sensibilidade para estimar a radiodensidade do parênquima hepático. O estabelecimento de valores de normalidade e a padronização de uma metodologia de avaliação permitem melhor caracterização de alterações na radiodensidade pelo exame tomográfico, auxiliando no estabelecimento de um diagnóstico e minimizando a necessidade de exames invasivos.

The objectives of the study reported here were to obtain medium values of hepatic parenchyma radiodensity in healthy dogs, and also describe the adaptation in canine specie of a tomographic density measurement technique, which has already been used in humans. For the accomplishment of this study tomographic exams were realized in eight young dogs without sex or breed definition. After the exams, the liver's degree of HU attenuation was determined through a mean value of three selected regions of interest (ROI) in hepatic parenchyma obtained in three different levels of cut. Additionally, a region of interest in the splenic parenchyma was analyzed in three different levels of cut for comparative evaluation between the organs. In the experimental group it was observed an X-ray attenuation mean value of 59.58±3.34 Hounsfield Units (HU). The density difference between hepatic and splenic parenchyma was a mean value of 4.69±7.77HU. In the present study, it was observed that computed tomography is a technique with high sensitivity to estimate hepatic parenchyma density. The establishment of reference values and the standardizing of an evaluation methodology allow a better characterization of radiodensity changes in the tomographic exams, assisting in establishing a diagnosis and minimizing the necessity of invasive testing to the patient.

Ultrassonografia quantitativa do fígado de gatos hígidos: nota prévia / Quantitative ultrasonography of the liver in healthy cats

O exame ultrassonográfico apresenta divergência na interpretação dos seus achados, devido à análise subjetiva e individual. Avaliou-se ultrassonograficamente a quantificação dos níveis de cinza de fígado de 18 gatos hígidos pela técnica de histograma, obtendo-se medidas referentes à ecogenicidade (LMEAN), ecotextura (NMOST/NALL) e desvio padrão da amplitude do eco (SD). As médias e desvio padrão dos valores encontrados foram para LMEAN 5,6 ±1,08, NMOST/NALL 28,31 ±3,84 e SD 11,48 ±1,77. Ressalta-se a importância da técnica do histograma na padronização de valores de normalidade referentes à ecogenicidade e ecotextura do fígado, favorecendo o diagnóstico e o monitoramento de hepatopatias difusas.

The ultrasonographic exam presents divergence in the interpretation of its findings, due to subjective and individual analysis. The livers of 18 healthy cats were evaluated by the ultrasonographic exam, making use of the gray-level histograms method. There were taken measures referring to the echogenicity (LMEAN), echotexture (NMOST/NALL) and echo amplitude standard deviation (SD). The mean values and standard deviations observed in this clinical assay were: LMEAN 5.6 ±1.08, NMOST/NALL 28.31 ±3.84 e SD 11.48 ±1.77. The gray-level histograms method is very important for the standardizing of hepatic echogenicity and echotexture values, helping in the diagnosis and monitoring of diffuse hepatopathies.

Doppler tecidual do miocárdio de gatos submetidos à anestesia dissociativa / Tissue Doppler imaging of the myocardium in cats submitted to dissociative anesthesia

O Doppler tecidual é uma técnica recente que permite avaliar a velocidade de movimentação do miocárdio durante as fases do ciclo cardíaco, fornecendo informações importantes da função cardíaca. Na medicina veterinária, estudos têm sido realizados para a caracterização de disfunções da contratilidade cardíaca e o estabelecimento de padrões de normalidade. O presente trabalho objetivou avaliar a velocidade de contração do miocárdio pela técnica de Doppler tecidual em gatos submetidos à anestesia dissociativa. Para tanto, foram utilizados nove gatos adultos, hígidos, sem distinção de sexo ou raça. Foram medidos os valores de Ea (velocidade máxima longitudinal no início da diástole), Aa (velocidade máxima longitudinal na sístole atrial) e Sa (velocidade máxima longitudinal na sístole ventricular) nas bordas lateral e septal do anel mitral. Os valores médios observados para Ea septal e Sa septal foram de 7,2±2,5cm s-1 e 6,3±1,7cm s-1, respectivamente. O valor médio obtido para Ea lateral foi de 12,0±4,1cm s-1, enquanto que o valor médio de Sa lateral foi de 8,3±1,6cm s-1. Foi obtido um valor médio de 7,0±3,1cm s-1 para Aa lateral e 4,7±1,5cm s-1 para Aa septal. A padronização dos valores médios da velocidade de contração do miocárdio na espécie felina é de grande importância, podendo auxiliar no diagnóstico precoce de alterações da função contrátil do coração. Em razão da escassez de estudos com a técnica de Doppler tecidual em gatos, os valores obtidos neste trabalho permitem a realização de estudos comparativos, auxiliando a aplicação dessa técnica em protocolos experimentais e no diagnóstico precoce de cardiopatias na espécie felina.

The tissue Doppler imaging (TDI) is a recent technique that allows the evaluation of the myocardium movement velocity during the cardiac cycle phases, providing important informations of the cardiac function. In veterinary medicine, studies have been realized for the characterization of cardiac contractility dysfunctions and to establish the normality patterns. The present work meant to evaluate the myocardium contractility velocity by the technique of TDI in healthy cats submitted to dissociative anesthesia. For that purpose, there were used nine cats, all adult, healthy and without sexual or breeding distinction. There were measured the values of Ea (early diastolic peak velocity), Aa (late diastolic peak velocity) and Sa (systolic peak velocity) in the lateral and septum wall sides. The mean values observed to septum Ea and septum Sa were of 7.2±2.5cm s-1 and 6.3±1.7cm s-1, respectively. The mean value obtained for lateral Ea was of 12.0±4.1cm s-1, while the mean value of lateral Sa was of 8.3±1.6cm s-1. It was obtained a mean value of 7.0±3.1cm s-1 for the lateral Aa, and 4.7±1.5cm s-1 for septum Aa. The standard of the myocardium contraction velocities mean values in the feline specie is of great importance, and it may help in the early diagnosis of heart contraction alterations. Due to the lack of studies with the TDI technique in cats, the values obtained in our work allow the realization of comparative studies, helping to apply this technique in experimental protocols and to the early diagnosis of cardiomyopathies in the feline specie.

Avaliação da fosfatase alcalina óssea e hepática em gatos com tirotoxicose induzida / Evaluation of bone and liver alkaline phosphatase in cats with induced

A tirotoxicose é caracterizada pelas excessivas concentrações séricas dos hormônios tiroidianos, podendo desencadear graves alterações no metabolismo ósseo, sendo a elevação da fosfatase alcalina total uma alteração laboratorial freqüentemente observada no hipertiroidismo felino. O aumento global dos níveis séricos de fosfatase alcalina pode ser decorrente de diferentes isoenzimas e, no caso do hipertiroidismo em humanos, as isoenzimas de origem óssea e hepática apresentam-se comumente elevadas. A partir da avaliação da bioquímica sérica de oito gatos com tirotoxicose induzida e elevação da fosfatase alcalina associada, o presente trabalho demonstra um aumento significativamente maior dos níveis séricos da fosfatase alcalina de origem óssea quando comparado com a isoenzima de origem hepática. Conclui-se que as alterações no metabolismo ósseo foram as principais responsáveis pelo aumento da fosfatase alcalina nos gatos com tirotoxicose induzida

Thyrotoxicosis, characterized by excessive serum levels of thyroidhormones, can cause serious effects in bone metabolism, elevating the total alkaline phosphatase, which is a frequent laboratorial alteration observed in feline hyperthyroidism. A rise in total serum levels of alkaline phosphatase can be caused by different isoenzymes, and in human hyperthyroidism, bone and hepatic isoenzymes are commonly increased. After serum biochemical evaluation of eight cats with induced thyrotoxicosis and associated elevation of alkaline phosphatase, the present paper shows a significant elevation of bone isoenzyme serum levels when compared with hepatic isoenzyme. It was possible to conclude that bone metabolism alterations were the main responsible for the increase of serum alkaline phosphatase in cats with induced thyrotoxicosis.

Ultrassonografia quantitativa do fígado em gatos com tirotoxicose induzida / Quantitative ultrasond of the liver in cats with induced thyrotoxicosis

Este estudo avaliou ultrassonograficamente o fígado de gatos submetidos à tirotoxicose induzida pela técnica de histograma dos níveis de cinza com o objetivo de melhor avaliar possíveis alterações hepáticas decorrentes do excesso de hormônios tiroidianos. Para isto, foram utilizados nove gatos hígidos, adulto-jovens, que receberam diariamente 150μg/kg de levotiroxina sódica, por 60 dias. O histograma hepático não demonstrou diferença estatística ao nível de 5% de significância entre os momentos avaliados; entretanto, as variações dos valores das variáveis estudadas sugeriram a promoção de aumento da heterogeneidade e diminuição da ecogenicidade do parênquima hepático quando comparado ao momento inicial. A avaliação citopatológica e histopatológica revelou quadro de hepatite tirotóxica em todos os animais

This study evaluated ultrasonographically the liver of cats submitted to induced thyrotoxicosis by the technique of gray-level histogram with the objective of better evaluating the possible hepatic alterations decurring from the excess of the thyroid hormones. For that, there were used nine adult-young healthy cats, which received daily 150ìg/kg of sodic levotiroxin, for 60 days. The hepatic histogram has not demonstrated statistical differences in the 5% level of significance between the evaluated moments; however, the variations of the studied variables’ values suggested an increasing of the heterogeneity and a decreasing of the echogenicity of the hepatic parenchyma when compared to the initial moment. The cytopathologic and histopathologic evaluations have shown of a clinical picture of thyrotoxic hepatitis in all the animals