Assessment of Dog Testis Perfusion by Colour and Pulsed-Doppler Ultrasonography and Correlation With Sperm Oxidative DNA Damage.

The assessment of testicular artery blood flow by colour and pulsed-Doppler ultrasonography is an important diagnostic technique to assess vascular perfusion. Recently, it has been suggested as a good predictor of sperm quality. On the other hand, through the alkaline Comet Assay, it is possible to quantify sperm oxidative DNA damage. The aim of this study was to evaluate the relationship between routine sperm parameters, testicular artery blood flow and oxidative DNA damage in canine sperm. Testicular ultrasonography and sperm collection were performed on 12 male dogs, with the animals being allocated into 2 groups, according to the classification of the ejaculates' quality, as normozoospermic (N; n = 7) or non-normozoospermic (OAT; n = 5). Seven dogs aged between 1.5 and 8.0 years old were included in group N and 5 dogs, aged between 2.0 and 11.0 years old, were included in group OAT. The sperm-rich fraction of the ejaculates was evaluated for sperm routine parameters and DNA damage by comet assay. Colour and pulsed-Doppler ultrasonography were used to evaluate the blood flow of the supratesticular and marginal arteries of right and left testis. Group OAT presented higher levels of sperm oxidative DNA damage (A.U.) in comparison to group N (N:11.7 ± 9.9; OAT:34.2 ± 6.1; P< .001). The peak of systolic velocity was positively correlated with sperm concentration (r = 0.685; P= .005). The resistive and pulsatility indexes (RI and PI) of the supratesticular artery were negatively correlated with sperm membrane integrity (HOST+) (r = -0.594; P = .042; r = -0.612; P = .035, respectively). The end diastolic velocity (EDV) of the supratesticular artery was positively correlated with sperm concentration (r = 0.748; P = .005) and negatively correlated with sperm oxidative DNA damage (r = -0.766; P = .004). Our results suggest that the assessment of the testicular artery blood flow by colour and pulsed-Doppler ultrasonography could be a good predictor of sperm quality in dogs in terms of sperm concentration, membrane integrity and sperm oxidative DNA damage.

Evaluation of gastrointestinal activity in healthy rabbits by means of duplex Doppler ultrasonography.

OBJECTIVE: To use duplex Doppler ultrasonography to compare gastrointestinal activity in healthy sedated versus nonsedated rabbits and to evaluate agreement between B-mode and pulsed-wave Doppler (PWD) ultrasonographic measurements. ANIMALS: 10 healthy client-owned rabbits brought for routine physical examination and 11 brought for routine ovariohysterectomy or castration. PROCEDURES: Duplex Doppler ultrasonography of the gastrointestinal tract was performed once for the 10 rabbits that underwent physical examination and twice (before and after presurgical sedation) for the 11 rabbits that underwent routine ovariohysterectomy or castration. Mean number of peristaltic contractions during a 30-second period was determined for the stomach, duodenum, jejunum, cecum, and colon from B-mode and PWD ultrasonographic images that had been video recorded. Findings for the duodenum and jejunum were compared between B-mode and PWD ultrasonography and between sedated and nonsedated rabbits. RESULTS: Duodenal and jejunal segments had measurable peristaltic waves; however, the stomach, cecum, and colon had no consistent measurable activity. B-mode and PWD ultrasonographic measurements for the duodenum and jejunum had high agreement. No significant difference was identified between nonsedated and sedated rabbits in mean number of peristaltic contractions of the duodenum or jejunum. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that both B-mode and PWD ultrasonography of the duodenum and jejunum may be suitable for noninvasive evaluation of small intestinal motility in rabbits and that the sedation protocol used in this study had no impact on measured peristaltic values.

A single dose of intravenous combretastatin A4-phosphate is reasonably well tolerated and significantly reduces tumour vascularization in canine spontaneous cancers.

Combretastatin A4-phosphate (CA4P) is an anti-tumour vascular targeting agent which selectively blocks tumour blood flow. Research on CA4P in rodent tumour models is extensive; however, knowledge of its effect on spontaneous cancer is scarce. This study was conducted in canine patients with spontaneous solid tumours. The goal was to assess the toxicity and efficacy of CA4P in various spontaneous tumour types. Eight dogs with spontaneous tumours were enrolled and treated with a single dose of 75 mg m-2 intravenous CA4P. The dogs were screened and monitored before and after injection. Pre- and post-treatment tumour blood flow was analysed in vivo by power Doppler ultrasound (PDUS) and contrast-enhanced ultrasound (CEUS). Vessel destruction and tumour necrosis were evaluated by histopathology. Clinically relevant toxicity was limited to one case of temporary tetraparesis; other adverse events were mild. Significant cardiovascular changes were mostly confined to changes in heart rate and cTnI levels. Macroscopic tumour size reduction was evident in 2 dogs. Based on PDUS and CEUS, CA4P induced a significant decrease in vascular index and tumour blood flow. Post-treatment, histopathology revealed a significant increase of necrotic tumoural tissue and a significant reduction in microvessel density in tumoural tissue. Anti-vascular and necrotizing effects of CA4P were documented in a variety of canine spontaneous cancers with only minimal side effects. This is the first study reporting the administration of CA4P to canine cancer patients with in vivo and ex vivo assessment, and a first step toward implementing CA4P in combination therapies in veterinary oncology patients. The use of CA4P in canine patients was approved and registered by the Belgian Federal Agency for Medicines and Health Products (FAMHP) (approval number 0002588, registration number 6518 ID 2F12).

Evaluation of canine hepatic masses by use of triphasic computed tomography and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography and correlation with histopathologic classification.

OBJECTIVE To determine clinical relevance for quantitative and qualitative features of canine hepatic masses evaluated by use of triphasic CT and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography and to compare diagnostic accuracy of these modalities for predicting mass type on the basis of histopathologic classification. ANIMALS 44 client-owned dogs. PROCEDURES Dogs with histopathologic confirmation (needle core, punch, or excisional biopsy) of a hepatic mass were enrolled. Triphasic CT and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography of each hepatic mass were performed. Seventy quantitative and qualitative variables of each hepatic mass were recorded by 5 separate observers and statistically evaluated with discriminant and stepwise analyses. Significant variables were entered in equation-based predictions for the histopathologic diagnosis. RESULTS An equation that included the lowest delayed-phase absolute enhancement of the mass and the highest venous-phase mass conspicuity was used to correctly classify 43 of 46 (93.5%) hepatic masses as benign or malignant. An equation that included only the lowest delayed-phase absolute enhancement of the mass could be used to correctly classify 42 of 46 (91.3%) masses (with expectation of malignancy if this value was < 37 Hounsfield units). For ultrasonography, categorization of the masses with cavitations as malignant achieved a diagnostic accuracy of 80.4%. CONCLUSIONS AND CLINICAL RELEVANCE Triphasic CT had a higher accuracy than ultrasonography for use in predicting hepatic lesion classification. The lowest delayed-phase absolute enhancement of the mass was a simple calculation that required 2 measurements and aided in the differentiation of benign versus malignant hepatic masses.

Avaliação do fluxo de saída do ventrículo esquerdo em gatos anestesiados submetidos ao pneumoperitônio e à posição deTrendelenburg / Evaluation left ventricle Outflow in cats anesthetized submitted to pneumoperitoneum and Trendelenburg position

Objetivou-se avaliar os efeitos do pneumoperitônio e da posição de Trendelenburg sobre o fluxo de saída do ventrículo esquerdo em gatos anestesiados. Quatorze gatos foram alocados aleatoriamente em dois grupos, ambos submetidos ao pneumoperitônio com 10mmHg de dióxido de carbono (CO2). No grupo controle (GC n=7), os animais foram submetidos apenas ao pneumoperitônio e, no grupo Trendelenburg (GTREN n=7), os animais foram colocados em cefalodeclive 20° após o pneumoperitônio. A indução anestésica foi realizada com isoflurano, utilizando-se caixa de indução. Posteriormente, os animais foram mantidos sob anestesia inalatória com o mesmo fármaco. Foram avaliados a velocidade do fluxo de saída do ventrículo esquerdo (VFSVE), os gradientes máximo (GmáxSVE) e médio (GmédSVE) de pressão e a integral velocidade-tempo (IVT). Os parâmetros foram mensurados nos momentos T0 (basal), antes da insuflação; T5 (cinco), T15 (quinze) e T30 (trinta) minutos após a insuflação. Os resultados mostraram um aumento da VFSVE no GC, em T15 e T30 (P=0,024), e um aumento do GmáxSVE no GC, em T30 (P=0,045). As variáveis não se alteraram significativamente em nenhum momento no GTREN. Dessa forma, conclui-se que a posição de Trendelenburg favoreceu o sistema cardiovascular, preservando os índices de fluxo sanguíneo na saída do ventrículo esquerdo.(AU)

The aim of this study was to evaluate the effects of pneumoperitoneum and Trendelenburg position on the left ventricular outflow in anesthetized cats. Fourteen cats were randomly divided into two groups, both submitted to pneumoperitoneum of 10 mmHg with carbon dioxide (CO2), and in the control group (GC n = 7) the animals were subjected only to pneumoperitoneum and the Trendelenburg group (n = 7 GTREN) the animals were placed in cefalodeclive 20° after pneumoperitoneum. Anesthesia of the animals was performed with isoflurane using induction box, keeping the animals under inhalation anesthesia with the same drug. We evaluated the speed of the left ventricular outflow (VFSVE), the maximum pressure gradient (GmáxSVE), mean pressure gradient (GmédSVE) and velocity-time integrals (IVT). The parameters were measured in time, T0 (baseline), before the insufflation; T5 (five); T15 (fifteen) and T30 (thirty) minutes after inflation. The results showed an increase in VFSVE in GC, T15 and T30 (p = 0,024) and an increase in GmáxSVE in GC in T30 (p = 0,045). The variables did not change significantly at any time in GTREN. Thus, it is concluded that the Trendelenburg position favored the cardiovascular system, preserving blood flow rates in the left ventricular outflow.(AU)

Portal Vein Dopplerflowmetry in healthy sheep according to age / Dopplerfluxometria da veia portal em ovinos hígidos de acordo com a idade

Pulsed Doppler ultrasound was used to evaluate portal blood flow, portal velocity and portal congestion index in 24 healthy sheep divided into groups (lambs, yearlings and ewes), according to age. Measurements were performed at the 11th right intercostal space using ideal insonation angle and uniform insonation method. Mean values obtained in each group were compared with one-way ANOVA, followed by Tukey post-hoc test. Portal velocity and portal blood flow were statistically similar between the groups (P>0.05). Mean portal velocity were 17.75; 17.13 and 16.75; while mean portal blood flow were 26.65; 31.04 and 24.32 for lambs, yearlings and ewes, respectively. Portal congestion index was statistically distinct between the groups and values for lambs, yearlings and ewes were 0.009; 0.058 and 0.09, respectively (P<0.01). Statistical differences were observed in portal vein diameter, portal vein area and portal congestion index between the groups, presumably due to influence of weight and not to age.(AU)

A ultrassonografia com Doppler pulsado foi utilizado para avaliar o fluxo sanguíneo portal, velocidade portal e índice de congestão portal em 24 ovinos saudáveis divididos em grupos (cordeiros, borregos e ovelhas), de acordo com a idade. As medições foram realizadas no 11o espaço intercostal direito utilizando ângulo de insonação ideal e método de inclusão uniforme. Os valores médios obtidos em cada grupo foram comparados com ANOVA, seguido pelo teste post-hoc de Tukey. A velocidade portal e o fluxo de sangue portal foram estatisticamente semelhantes entre os grupos (P>0,05). A velocidade portal média foram 17,75; 17,13 e 16,75; enquanto o fluxo de sangue portal médios foram 26,65; 31,04 e 24,32 para cordeiros, borregos e ovelhas, respectivamente. O índice de congestão portal foi estatisticamente diferente entre os grupos e os valores para cordeiros, novilhos e ovelhas foram 0,009; 0,058 e 0,09, respectivamente (P<0.01). Observaram-se diferenças estatísticas nos diâmetros da veia porta, na área da veia porta e nos índices de congestão portal entre os grupos, provavelmente devido à influência do peso e não pela idade.(AU)

Evaluation of arterial digital blood flow using Doppler ultrasonography in healthy dairy cows.

BACKGROUND: Local circulatory disturbances have been implicated in the development of foot disorders in cattle. The goals of this study were to evaluate the suitability of the interdigital artery in the pastern region in both hind limbs using pulsed-wave (PW) Doppler ultrasonography and to investigate quantitative arterial blood flow variables at that site in dairy cows. An Esaote MyLabOne ultrasound machine with a 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the pastern region in both hind limbs of 22 healthy German Holstein cows. The cows originated from three commercial farms and were restrained in a standing hoof trimming chute without sedation. RESULTS: A PW Doppler signal suitable for analysis was obtained in 17 of 22 cows. The blood flow profiles were categorised into four curve types, and the following quantitative variables were measured in three uniform cardiac cycles: vessel diameter, pulse rate, maximum systolic velocity, maximum diastolic velocity, end-diastolic velocity, reverse velocity, maximum time-averaged mean velocity, blood flow rate, resistance index and persistence index. The measurements did not differ among cows from the three farms. Maximum systolic velocity, vessel diameter and pulse rate did not differ but other variables differed significantly among blood flow profiles. CONCLUSIONS: Differences in weight-bearing are thought to be responsible for the normal variability of blood flow profiles in healthy cows. The scanning technique used in this report for evaluation of blood flow in the interdigital artery appears suitable for further investigations in healthy and in lame cows.

Eliminação de Dioctophyme renale pela urina em canino com dioctofimatose em rim esquerdo e cavidade abdominal - Primeiro relato no Rio Grande do Sul / Elimination of Dioctophyme renale to urine in canines with dioctophymosis in the left kidney and abdominal cavity - First report in Rio Grande do Sul

Dioctophyme renale é um parasito que afeta tanto animais como humanos e tem como órgão de eleição o rim direito. Relata-se o caso clínico-cirúrgico de um paciente canino com histórico de eliminação de três exemplares de D. renale pela urina e presença de parasitos no rim esquerdo e na cavidade abdominal. No Hospital de Clínicas Veterinárias da Universidade Federal de Pelotas, foram realizados exames pré-cirúrgicos, entre eles a ultrassonografia abdominal, que identificou a localização dos nematódeos, e o exame de Doppler pulsado dos vasos intrarrenais, que demonstrou aumento nos índices resistivos nas regiões avaliadas. O paciente foi conduzido para a realização de laparotomia exploratória, sendo removidos 23 parasitos da cavidade abdominal. A presença de D. renale causa graves lesões nos rins e nos demais órgãos da cavidade abdominal, sendo essencial o diagnóstico precoce e a remoção dos nematódeos para recuperação do paciente.(AU)

Dioctophyme renale is a parasite that attacks animals as well as humans and has the right kidney as a preferred target organ. This document reports the case of a clinical-chirurgical canine patient with a history of elimination of three D. renale samples through its urine and presence of parasites at its left kidney and abdominal cavity. Pre-cirurgical exams were performed at the Veterinary Hospital of the Federal University of Pelotas. Among these exams, abdominal ultrasonography identified the nematode's location and the Pulse-Doppler of the intrarenal vessels showed an increase in the resistive indices of the evaluated areas. An Exploratory Laparotomy was conducted with the patient who had 23 parasites removed from its abdominal cavity. The presence of D. renale causes severe lesions at kidneys and other organs of the abdominal cavity, for this reason early diagnosis and nematode´s removal are essential for the patient's recovery.(AU)

Pulsed-wave Doppler ultrasonographic evaluation of hepatic vein in dogs with tricuspid regurgitation.

This study was performed to identify the relationships between hepatic vein (HV) measurements, including flow velocity and waveform, using pulsed-wave (PW) Doppler ultrasonography, and the severity of tricuspid regurgitation (TR) in dogs. The study included 22 dogs with TR and 7 healthy dogs. The TR group was subdivided into 3 groups according to TR jet profile obtained by echocardiography. The hepatic venous waveform was obtained and classified into 3 types. A variety of HV measurements, including the maximal velocities of the atrial systolic, systolic (S), end ventricular systolic, and diastolic (D) waves and the ratio of the S- and D- wave velocities (S/D ratio), were acquired. TR severity was significantly correlated with the S- (r = -0.380, p = 0.042) and D- (r = 0.468, p = 0.011) wave velocities and the S/D ratio (r = -0.747, p ＜ 0.001). Receiver operating characteristic curve analysis revealed the highest sensitivity and specificity for the S/D ratio (89% and 75%, respectively) at a threshold of 0.97 with excellent accuracy (AUC = 0.911, p ＜ 0.001). In conclusion, PW Doppler ultrasonography of the HV can be used to identify the presence of significant TR and to classify TR severity in dogs.

Spleen evaluation using contrast enhanced ultrasonography and Doppler in dogs with subclinical ehrlichiosis / Ultrassonografia por contraste com microbolhas e Doppler na avaliação do baço de cães com erliquiose subclínica

The aim of this study was to evaluate the splenic parenchyma of dogs with subclinical ehrlichiosis using Doppler and contrast-enhanced ultrasonography and provide reference values for this organ in affected animals. Seventeen dogs naturally infected with E. canis were selected for this study. Splenic parenchyma echotexture and echogenicity, size and borders were determined by ultrasound scan. The vascular indices of the splenic artery were determined by Doppler. SonoVue, at 0.1mL per animal, was used in microbubble contrast-enhanced ultrasonography to determine wash in, wash out and peak enhancement time in the splenic tissue. B-mode ultrasonography revealed splenomegaly with rounded borders, heterogeneous echotexture and mixed echogenicity. The vascular indices of the splenic artery were: systolic velocity of 22.59±8.07cm/s, diastolic velocity of 5.25±4.66cm/s and resistance index of 0.71±0.14; values not yet reported in Veterinary Medicine. Contrast-enhanced ultrasonography recorded wash in time of 5.31±0.7s, peak enhancement time of 18.56±2.90s and wash out time of 94.56±35.21s. The combination of conventional ultrasonography of the spleen and hemodynamic evaluation by Doppler and contrast-enhanced ultrasonography is important for the diagnosis of canine ehrlichiosis and could help monitor the clinical evolution of subclinical cases.

O objetivo deste estudo foi avaliar o parênquima esplênico de cães com erliquiose na fase subclínica, por meio do Doppler e da ultrassonografia por contraste com microbolhas. Dezessete cães naturalmente infectados por E. canis na fase subclínica foram selecionados para este estudo. Por meio da ultrassonografia, avaliou-se a ecotextura, a ecogenicidade, o tamanho e os bordos do baço e, pelo Doppler, foram determinados os índices vasculares da artéria esplênica dos cães. Para a avaliação por contraste com microbolhas, foi utilizado SonoVue, na dosagem de 0,1mL por animal, e determinou-se o tempo de entrada e saída, bem como o pico de realce no tecido esplênico. Ao exame modo-B, foram observadas esplenomegalia com presença de bordas arredondadas, ecotextura heterogênea e ecogenicidade mista do baço. Ao Doppler, foram encontrados valores para os índices vasculares da artéria esplênica: velocidade sistólica: 22,59±8,07cm/s; velocidade diastólica: 5,25±4,66cm/s; e índice de resistência: 0,71±0,14, valores ainda não descritos em veterinária. Pela ultrassonografia com contraste, observaram-se valores para wash-in de 5,31±0.7s, pico de realce de 18,56±2.90s e wash-out de 94,56±35.21s. A ultrassonografia convencional do baço de cães com erliquiose, associada com a utilização do método Doppler e a ultrassonografia contrastada, é uma importante ferramenta na triagem diagnóstica e pode auxiliar a monitoração e a evolução de animais na fase subclínica.

Ultrassonografia modo B e Doppler na avaliação renal de cães após administração intravenosa de meio de contraste iodado: validação da técnica / B-mode and Doppler ultrasonography in the renal evaluation of dogs after intravenous administration of iodinated contrast media: technical validation

Meios de contraste iodado podem promover efeitos hemodinâmicos relacionados à vasoconstrição intrarrenal prolongada e redução da perfusão, predispondo à hipóxia e isquemia medular. Alterações de resistência vascular renal podem representar os primeiros sinais de mudança funcional desse órgão. A técnica Doppler pulsado é considerada acessível, não invasiva e permite avaliar a dinâmica vascular dos rins, por meio da aferição dos índices de resistividade (IR) e pulsatilidade (IP). Contudo, na espécie canina, a aquisição de traçados espectrais pode ser penosa devido às dificuldades de varredura e captação de sinal Doppler, sobretudo em relação ao rim direito, devido à sua localização dorsocranial na cavidade abdominal, o que prolonga substancialmente a realização do exame. O objetivo deste estudo é comprovar que a avaliação Doppler pulsado das artérias intrarrenais do rim esquerdo de cães representa a repercussão hemodinâmica renal da administração intravenosa de meios de contraste iodado não sendo necessária a realização do exame nos dois rins. Foram avaliados ambos os rins de seis cadelas adultas em quatro momentos distintos: antes da infusão intravenosa do contraste radiológico e após 1,5 horas, 24 horas e 48 horas, por meio da análise subjetiva da morfologia, ecogenicidade cortical e grau de perfusão renais e análise objetiva do comprimento, volume e resistência vascular intrarrenais (IR e IP). Os parâmetros avaliados ao modo B e Doppler dos rins direito e esquerdo não apresentaram diferenças estatisticamente significativas entre si em cada momento avaliado. Assim, constatou-se que o exame ultrassonográfico Doppler pulsado do rim esquerdo representou a repercussão hemodinâmica renal da aplicação intravenosa de meios de contraste iodado, desde que morfometria, morfologia, ecogenicidade cortical e perfusão de ambos os rins fossem consideradas semelhantes na abordagem ultrassonográfica inicial...

Iodinated contrast media can provide hemodynamic effects related to prolonged intrarenal vasoconstriction and reduced perfusion, predisposing to hypoxia and medular ischemia. Changes in the renal vascular resistance may represent the first sign of impaired renal function. Pulsed wave Doppler sonography is low cost, non-invasive and allows renal hemodynamic evaluation by resistivity (RI) and pulsatility (PI) indices. However in dogs, spectral Doppler waveform may be hard to obtain due to scanning difficulties and lack of signal Doppler. This fact occurs mostly in the right kidney because of its cranial and dorsal position in the abdominal cavity and may prolong the exam. The purpose of this study is to prove that the pulsed wave Doppler interrogation of the canine left kidney intrarenal arteries represent the renal hemodynamic effects of intravenous administration of iodinated contrast media and is not necessary to perform the exam in both kidneys. Right and left kidneys of six adult dogs were evaluated at four different times: before intravenous contrast infusion and after 1.5 hours, 24 hours and 48 hours, subjectively by using renal morphology, cortical echogenicity and renal perfusion, and objectively by using renal length, renal volume and intrarenal vascular resistance (RI and PI). No significant differences were noted between the parameters assessed by B mode and Doppler sonography of the right and left kidney in each evaluated moment. Thus, it was noted that pulsed wave Doppler sonographic evaluation of the left kidney represented the renal hemodynamic response of intravenous iodinated contrast media administration, only if both kidneys presented similar morphometry, morphology, cortical echogenicity, and perfusion during the first assessment...

Pulsed tissue Doppler imaging of the left ventricular septal mitral annulus in healthy dogs.

This study evaluated pulsed TDI variables including the isovolumic time interval and duration of the major wave in a population of large healthy dogs. Longitudinal myocardial motion at the septal mitral annulus was evaluated with pulsed TDI in 45 healthy adult dogs. Maximal myocardial velocities, isovolumic time intervals, and duration of the myocardial waves were measured. The correlation between time intervals and velocity variables was also investigated. The mean maximal systolic velocity was 6.92 ± 1.78 cm/sec, the mean early diastolic velocity (Em) was 6.58 ± 1.81 cm/sec, the mean late diastolic velocity (Am) was 5.10 ± 2.00 cm/sec, the mean isovolumic contraction time (IVCT) was 53.61 ± 95.13 msec, and the mean isovolumic relaxation time (IVRT) was 26.74 ± 57.24 msec. The early diastolic mitral inflow velocity (E)/Em ratio was 10.94 ± 3.27 while the Em/Am ratio was 1.40 ± 0.40. There was a negative correlation between Am duration and Am amplitude, and a positive correlation between the IVRT and Em/Am ratio (p < 0.05). The normal LV parameter using pulsed TDI method could be used as the reference range for identifying myocardial dysfunction in dogs.

Colour and pulsed Doppler ultrasonographic study of the canine testis.

This study was performed to characterize the normal blood flow of the canine testis and to measure the peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) of testicular arteries weekly during a period of 6 months in five healthy Beagle dogs and to evaluate whether there were any change along this time. The ultrasonographic exams were made with an 11 MHz linear transducer. The vessels of the testes were subdivided into three categories: supratesticular arteries, marginal artery and intratesticular vessels. At the supratesticular arteries, two measurements were recorded at the cranial and the looping parts. No significant differences in any of the parameters studied were observed for the 6 months that the study was performed. The cranial part of the supratesticular artery showed a flow pattern of high-resistive vessel, whereas in the looping part of the supratesticular artery, marginal and intratesticular arteries, the flow showed a low-resistance pattern. PSV, RI and PI values were higher at the cranial part of the supratesticular artery, followed by the looping part of the supratesticular artery, marginal and intratesticular vessels. EDV measurements were higher in the looping part of the supratesticular artery.

Comparison of flow-mediated vasodilation in femoral and brachial arteries in healthy dogs.

OBJECTIVE: To compare flow-mediated vasodilation (FMD) measurements in brachial and femoral arteries of healthy dogs habituated to the assessment method, evaluate repeatability of these measurements, and investigate effects of blood pressure cuff inflation time on femoral artery FMD measurements. ANIMALS: 11 healthy adult Miniature Schnauzers. PROCEDURES: Arterial luminal diameter and blood flow velocity integral (FVI) were measured before and after cuff inflation of 5 minutes' (brachial and femoral arteries) or 3 minutes' duration (femoral artery) in separate experiments. A blood pressure cuff was inflated to > 200 mm Hg distal to each imaging site to increase local blood flow to induce reactive hyperemia. Changes in FVI after cuff deflation, FMD, and between-dog and within-dog coefficients of variation (CVs) were determined. RESULTS: After cuff inflation of 5 minutes' duration, greater changes were detected in median change in FVI and FMD of brachial arteries (174.0% and 8.0%, respectively), compared with values determined for femoral arteries (32.0% and 2.1%, respectively). Between-dog CV for brachial artery FMD was 34.0%, compared with 89.6% for femoral arteries, and within-dog CV was 32.5% for brachial arteries versus 51.6% for femoral arteries after cuff inflation of 5 minutes' duration. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy Miniature Schnauzers, FMD was greater and more repeatable in brachial arteries than in femoral arteries. Reactive hyperemia was inconsistently induced in femoral arteries following 3- or 5-minute cuff inflation times. Brachial, but not femoral, artery FMD measurement is a potentially useful research technique for measurement of endothelial function in dogs.

The morphology and haemodynamics of the rabbit renal artery: evaluation by conventional and contrast-enhanced ultrasonography.

The purpose of this study was to test the morphology and haemodynamics of the renal artery in the rabbit as evaluated by conventional and contrast-enhanced ultrasonography (CEUS). The morphology and haemodynamics of the rabbit renal artery, including the diameter, which were measured using B-mode ultrasonography (US), colour Doppler US and CEUS, and systolic velocity, diastolic velocity and resistive index (RI) were measured using pulsed wave Doppler US. CEUS was used to measure the renal artery diameter: 0.21 ± 0.04 cm (right) and 0.21 ± 0.03 cm (left). Values of the main renal artery diameter obtained from CEUS significantly correlated with those of digital subtraction angiography. The blood flow velocity of the right main renal artery was 44.20 ± 8.71/18.92 ± 6.26 cm/s (systolic/diastolic) and 36.30 ± 6.89/17.64 ± 5.58 cm/s (systolic/diastolic), at its origin from the aorta and at the renal hilus, respectively. The blood flow velocity of the left main renal artery was 45.10 ± 8.49/19.00 ± 6.80 cm/s (systolic/diastolic) and 41.70 ± 10.25/19.55 ± 7.90 cm/s (systolic/diastolic), at its origin from the aorta and at the renal hilus, respectively. Conventional US provides a more feasible modality for measuring the morphology and haemodynamics of the rabbit renal artery. CEUS is a more accurate method for measuring diameter. This information on the morphology and haemodynamics of the rabbit renal artery might be helpful for researchers.

Noninvasive estimation of central venous pressure in anesthetized dogs by measurement of hepatic venous blood flow velocity and abdominal venous diameter.

Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B-mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B-mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a-, S- and v-wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v-wave velocity (0.823), S-wave velocity (-0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v-wave velocity (r = 0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy.

Pathologic correlation of resistive and pulsatility indices in canine abdominal lymph nodes.

We assessed the ability of the resistive index (RI) and pulsatility index (PI) to allow differentiation between normal, reactive, and neoplastic lymph nodes. Forty-seven medial iliac and 54 mesenteric lymph nodes from 83 dogs were evaluated sonographically. A cytologic sample was obtained in each dog that allowed categorization into one of the categories defined above. We found a significant difference in the RI and PI in nonneoplastic vs. neoplastic medial iliac and mesenteric lymph nodes. Values higher than 0.67 for the RI and 1.02 for the PI in medial iliac lymph nodes and higher than 0.76 for the RI and 1.23 for the PI in mesenteric lymph nodes had a high sensitivity and specificity for differentiating benign from neoplastic lymph nodes.

Multichannel pulsed Doppler signal processing for vascular measurements in mice.

The small size, high heart rate and small tissue displacement of a mouse require small sensors that are capable of high spatial and temporal tissue displacement resolutions and multichannel data acquisition systems with high sampling rates for simultaneous measurement of high fidelity signals. We developed and evaluated an ultrasound-based mouse vascular research system (MVRS) that can be used to characterize vascular physiology in normal, transgenic, surgically altered and disease models of mice. The system consists of multiple 10/20MHz ultrasound transducers, analog electronics for Doppler displacement and velocity measurement, signal acquisition and processing electronics and personal computer based software for real-time and off-line analysis. In vitro testing of the system showed that it is capable of measuring tissue displacement as low as 0.1mum and tissue velocity (mum/s) starting from 0. The system can measure blood velocities up to 9m/s (with 10MHz Doppler at a PRF of 125kHz) and has a temporal resolution of 0.1 milliseconds. Ex vivo tracking of an excised mouse carotid artery wall using our Doppler technique and a video pixel tracking technique showed high correlation (R(2)=0.99). The system can be used to measure diameter changes, augmentation index, impedance spectra, pulse wave velocity, characteristic impedance, forward and backward waves, reflection coefficients, coronary flow reserve and cardiac motion in murine models. The system will facilitate the study of mouse vascular mechanics and arterial abnormalities resulting in significant impact on the evaluation and screening of vascular disease in mice.

Spectral waveform analysis of intranodal arterial blood flow in abnormally large superficial lymph nodes in dogs.

OBJECTIVE: To evaluate pulsed-wave Doppler spectral parameters as a method for distinguishing between neoplastic and inflammatory peripheral lymphadenopathy in dogs. SAMPLE POPULATION: 40 superficial lymph nodes from 33 dogs with peripheral lymphadenopathy. PROCEDURES: 3 Doppler spectral tracings were recorded from each node. Spectral Doppler analysis including assessment of the resistive index, peak systolic velocity-to-end diastolic velocity (S:D) ratio, diastolic notch velocity-to-peak systolic velocity (N:S) ratio, and end diastolic velocity-to-diastolic notch velocity ratio was performed for each tracing. Several calculation methods were used to determine the Doppler indices for each lymph node. After the ultrasonographic examination, fine needle aspirates or excisional biopsy specimens of the examined lymph nodes were obtained, and lymphadenopathy was classified as either inflammatory or neoplastic (lymphomatous or metastatic) via cytologic or histologic examination. Results of Doppler analysis were compared with cytologic or histopathologic findings. RESULTS: The Doppler index with the highest diagnostic accuracy was the S:D ratio calculated from the first recorded tracing; a cutoff value of 3.22 yielded sensitivity of 91%, specificity of 100%, and negative predictive value of 89% for detection of neoplasia. Overall diagnostic accuracy was 95%. At a sensitivity of 100%, the most accurate index was the N:S ratio calculated from the first recorded tracing; a cutoff value of 0.45 yielded specificity of 67%, positive predictive value of 81%, and overall diagnostic accuracy of 86.5%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that noninvasive Doppler spectral analysis may be useful in the diagnosis of neoplastic versus inflammatory peripheral lymphadenopathy in dogs.

Evaluation of Doppler ultrasonography for the measurement of blood flow in young loggerhead sea turtles (Caretta caretta).

The aim of this study was to identify ultrasound accessible blood vessels in the loggerhead sea turtle (Caretta caretta) and describe their Doppler waveform patterns, peak systolic velocity, mean velocity, systolic/diastolic ratio as well as pulsatility and resistive indices. B-mode, colour and pulsed-wave Doppler examinations were performed on 10 turtles. Flow measurements were recorded for the left and right aorta, epigastric and internal iliac arteries, and right hepatic vein. Additionally, the large blood vessels of three dead turtles were injected with latex and dissected for anatomical support. A parabolic flow velocity profile was observed in all arteries. The waveforms of the right and left aortic arteries showed an unusual pattern when compared with mammals. The hepatic vein flow velocity waveform of the loggerhead sea turtle was found to be similar to that in the dog, although the flow velocity in the C-wave was higher than that in the A-wave. The low resistance flow pattern observed suggests that the loggerhead sea turtle's organs require a continuous blood supply.