Physical principles of Doppler ultrasonography

A ultra-sonografia Doppler é um método relativamente recente dentro da rotina veterinária que fornece informações em tempo real da arquitetura vascular e dos aspectos hemodinâmicos dos vasos sanguíneos examinados em diversos órgãos vitais. Pode determinar a presença, a direção e o tipo de fluxo sanguíneo. Esta revisão de literatura compila as informações sobre os princípios físicos da ultra-sonografia Doppler. A ampliação do conhecimento desta tecnologia possibilita a melhor compreensão das aplicações e limitações deste método diagnóstico, que tem se tornado rotina na medicina veterinária de pequenos animais.Doppler ultrasonography is a relatively new diagnostic tool in veterinary medicine that provides real time details about vascular architecture and hemodynamic aspects of examinated blood vessels in several internal organs. Doppler can identify the presence, direction and type of blood flow. This literature review provides information about the physical principles of Doppler ultrasonography. The enlargement of expertise about this technology lead to a better comprehension of its use and limitations as a diagnostic technique, which already becomes usual in veterinary medicine of small animals

Thyroid hormonal disturbances related to treatment of hepatitis C with interferon-alpha and ribavirin

OBJECTIVE: To characterize thyroid disturbances induced by interferon-alpha and ribavirin therapy in patients with chronic hepatitis C. INTRODUCTION: Interferon-alpha is used to treat chronic hepatitis C infections. This compound commonly induces both autoimmune and non-autoimmune thyroiditis. METHODS: We prospectively selected 26 patients with chronic hepatitis C infections. Clinical examinations, hormonal evaluations, and color-flow Doppler ultrasonography of the thyroid were performed before and during antiviral therapy. RESULTS: Of the patients in our study, 54% had no thyroid disorders associated with the interferon-alpha therapy but showed reduced levels of total T3 along with a decrease in serum alanine aminotransferase. Total T4 levels were also reduced at 3 and 12 months, but free T4 and thyroid stimulating hormone (TSH) levels remained stable. A total of 19% of the subjects had autoimmune interferon-induced thyroiditis, which is characterized by an emerge of antithyroid antibodies or overt hypothyroidism. Additionally, 16% had non-autoimmune thyroiditis, which presents as destructive thyroiditis or subclinical hypothyroidism, and 11% remained in a state of euthyroidism despite the prior existence of antithyroidal antibodies. Thyrotoxicosis with destructive thyroiditis was diagnosed within three months of therapy, and ultrasonography of these patients revealed thyroid shrinkage and discordant change in the vascular patterns. DISCUSSION: Decreases in the total T3 and total T4 levels may be related to improvements in the hepatocellular lesions or inflammatory changes similar to those associated with nonthyroidal illnesses. The immune mechanisms and direct effects of interferon-alpha can be associated with thyroiditis. CONCLUSION: Interferon-alpha and ribavirin induce autoimmune and non-autoimmune thyroiditis and hormonal changes (such as decreased total T3 and total T4 levels), which occur despite stable free T4 and TSH levels. A thyroid hormonal evaluation, including the analysis of the free T4, TSH, and antithyroid antibody levels, should be mandatory before therapy, and an early re-evaluation within three months of treatment is necessary as an appropriate follow-up

Can Doppler or contrast-enhanced ultrasound analysis add diagnostically important information about the nature of breast lesions?

OBJECTIVES: Despite evidence suggesting that Doppler ultrasonography can help to differentiate between benign and malignant breast lesions, it is rarely applied in clinical practice. The aim of this study was to determine whether certain vascular features of breast masses observed by duplex Doppler and color Doppler ultrasonography (before and/or after microbubble contrast injection) add information to the gray-scale analysis and support the Breast Imaging-Reporting and Data System (BI-RADS) classification. METHODS: Seventy solid lesions were prospectively evaluated with gray-scale ultrasonography, color Doppler ultrasonography, and contrast-enhanced ultrasonography. The morphological analysis and lesion vascularity were correlated with the histological results. RESULTS: Percutaneous core biopsies revealed that 25/70 (17.5%) lesions were malignant, while 45 were benign. Hypervascular lesions with tortuous and central vessels, a resistive index (RI)≥0.73 before contrast injection, and an RI≥0.75 after contrast injection were significantly predictive of malignancy (

Blood flow velocity in monocular retinoblastoma assessed by color doppler

OBJECTIVE: To analyze the flow of retrobulbar vessels in retinoblastoma by color Doppler imaging. METHODS: A prospective study of monocular retinoblastoma treated by enucleation between 2010 and 2014. The examination comprised fundoscopy, magnetic resonance imaging, ultrasonography and color Doppler imaging. The peak blood velocities in the central retinal artery and central retinal vein of tumor-containing eyes (tuCRAv and tuCRVv, respectively) were assessed. The velocities were compared with those for normal eyes (nlCRAv and nlCRVv) and correlated with clinical and pathological findings. Tumor dimensions in the pathological sections were compared with those in magnetic resonance imaging and ultrasonography and were correlated with tuCRAv and tuCRVv. In tumor-containing eyes, the resistivity index in the central retinal artery and the pulse index in the central retinal vein were studied in relation to all variables. RESULTS: Eighteen patients were included. Comparisons between tuCRAv and nlCRAv and between tuCRVv and nlCRVv revealed higher velocities in tumor-containing eyes (

Correlation between isolated sonographic finding of umbilical cord cyst and fetal anomalies

OBJETIVO: Correlacionar o achado ultra-sonográfico isolado de cisto de cordão umbilical com anomalias fetais, como cromossomopatias e alterações estruturais. Segundo a literatura médica, as implicações clínicas do achado ultra-sonográfico de cisto de cordão nos segundo e terceiro trimestres de gestação estão bem estabelecidas, entretanto, quando no primeiro trimestre, o significado ainda permanece controverso. MATERIAIS E MÉTODOS: Foi realizado estudo retrospectivo de gestantes da população geral, consecutivas, com fetos únicos e vivos, que apresentavam apenas o achado de cisto de cordão umbilical, num período de dez anos (1996-2006). Em todos os casos foram realizados exames ultra-sonográficos para o rastreamento de anomalias fetais após o diagnóstico de cisto de cordão. Os recém-nascidos e o cordão umbilical foram examinados após o parto para se verificar a presença de anomalias. RESULTADOS: Foram estudados nove casos que apresentavam cisto de cordão umbilical como único achado, sem outros marcadores ultra-sonográficos de anomalias fetais. Detectaram-se dois casos no primeiro trimestre de gestação e sete nos segundo e terceiro trimestres. Dois casos foram submetidos a estudo citogenético fetal, por meio de amniocentese. Nenhum recém-nascido apresentou anomalias estruturais ou aneuploidia. CONCLUSÃO: O achado ultra-sonográfico isolado de cisto de cordão umbilical não significou aumento de risco para anomalias estruturais ou aneuploidias.OBJECTIVE: To correlate the isolated sonographic finding of umbilical cord cyst with fetal anomalies such as chromosomopathies and structural changes. According to the medical literature, the clinical implications of the sonographic finding of umbilical cord cyst in the second and third trimesters of pregnancy are well established; however, the meaning of this finding in the first trimester still remains controversial. MATERIALS AND METHODS: A retrospective study was developed with consecutive, pregnant women with single living fetuses presenting with umbilical cord cyst as an isolated finding, over a 10-year period (1996-2006). Ultrasound studies were performed in all cases for screening of fetal anomalies after the diagnosis of umbilical cord cyst. Neonates and umbilical cords were evaluated after delivery for the presence of abnormalities. RESULTS: Nine cases presenting umbilical cord cyst as a sole finding with no other sonographic marker for fetal abnormality were evaluated. Two cases were detected in the first pregnancy trimester and seven cases in the second and third trimesters. Fetal cytogenetic study was done by means of amniocentesis in two cases. No newborn presented with structural anomalies or aneuploidy. CONCLUSION: Isolated sonographic finding of umbilical cord cyst did not imply increased risk for fetal structural anomalies or aneuploidies

Injeção percutânea de etanol guiada por ultra-sonografia para paliação de carcinoma de paratireóide não-extirpável

BACKGROUND: Severe hypercalcemia is the leading cause of death in patients with parathyroid carcinoma. Non-curative resection and pharmacological measures may be useful for palliation in cases with recurrent and metastatic disease. Palliative treatment with intra-neoplastic ethanol injection has not been reported yet. METHODS: Ultrasound-guided percutaneous alcohol injection in one patient with unresectable parathyroid carcinoma is reported. RESULTS: One male patient with extensive recurrent parathyroid carcinoma suffering from severe hypercalcemia, refractory to all available medical measures has undergone two percutaneous ethanol injections. No major complications ensued and parathormone levels decreased from 2,990 pg/mL to 2,230pg/ml after the first injection, and to 1,104pg/mL after the second one. Calcium levels decreased from 19.8 mg/dL to 16.1 mg/dL and to 14.5 mg/dL, respectively. The patient died of metabolic hypercalcemia complications about two months later, probably due to mediastinal disease progression. CONCLUSION: Ultrasound-guided percutaneous ethanol injection may be employed to palliate parathyroid carcinoma in selected cases, with a transitory decrease in PTH and calcium levels.INTRODUÇÃO: A hipercalcemia severa é a principal causa de óbito nos pacientes com carcinoma de paratireóide. Em casos com recidiva ou doença metastática inoperáveis, a ressecção não curativa e as medidas farmacológicas podem ser úteis para a paliação. O presente estudo relata a experiência com a injeção de etanol na neoplasia para tratamento paliativo em um caso. MÉTODO: Relato da injeção percutânea de etanol em paciente com carcinoma de paratireóide recidivado, não passível de ressecção. RESULTADO: Paciente masculino com hipercalcemia refratária a tratamento clínico decorrente de recidiva local não extirpável de carcinoma de paratireóide. Submetido a duas sessões de injeção percutânea de etanol. Não houve complicações maiores. Após a primeira injeção, o nível de paratormônio reduziu-se de 2.990 pg/mL para 2.230 pg/ml. Após a segunda injeção, o nível caiu para 1.104 pg/mL. A calcemia declinou de 19,8 mg/dL para 16,1 mg/dL e 14,5 mg/dL, respectivamente. O paciente faleceu de complicação metabólica, cerca de dois meses depois, possivelmente pela progressão da doença no mediastino. CONCLUSÃO: A injeção percutânea de etanol pode ser utilizada para paliação do carcinoma de paratireóide em casos selecionados, com queda transitória do nível de hormônio da paratireóide e da calcemia

Sonographic determination of liver size in healthy newborns, infants and children under 7 years of age

OBJETIVO: Determinar o tamanho do fígado de crianças normais, entre 0 e 7 anos de idade, por ultrassonografia, correlacionando os valores obtidos com: idade, sexo, estatura, peso corporal e índice de massa corpórea. MATERIAIS E MÉTODOS: Foram examinadas 584 crianças saudáveis, subdivididas em 11 grupos etários, sendo medidos o diâmetro crânio-caudal do lobo esquerdo, na linha médio-esternal, e o diâmetro crânio-caudal da superfície posterior do lobo direito, na linha hemiclavicular. Na análise estatística foram aplicados: a) coeficiente de correlação de Pearson (estudo de correlação); b) teste t de Student não-pareado (comparação das medidas entre os sexos); c) modelos de regressão não linear (nomogramas). RESULTADOS: O tamanho hepático apresentou aumento progressivo, do nascimento aos 7 anos de idade, proporcionalmente menor que o crescimento corporal, correlacionado com idade, estatura e peso corporal (r > 0,70), não havendo correlação com índice de massa corpórea (r < 0,11). Não se observou diferença consistente das medidas hepáticas em relação ao sexo. CONCLUSÃO: Valores do tamanho do fígado de crianças normais (entre 0 e 7 anos) foram determinados mediante aplicação de técnica padronizada, verificando-se forte correlação com a idade e indicadores antropométricos. Nomogramas demonstram as variações normais do tamanho hepático na população estudada, com crescimento diferenciado para cada lobo.OBJECTIVE: The present study was aimed at sonographically determining the liver size in healthy newborns, infants and children under 7 years of age, correlating results with age, sex, height, body weight and body mass index. MATERIALS AND METHODS: A total of 584 healthy children subdivided into 11 age groups were evaluated with measurements of the left lobe craniocaudal diameter at the midsternal line, and the craniocaudal diameter of the right lobe posterior surface at the midclavicular line. The following tests were utilized for statistical analysis: a) Pearson's correlation coefficient (correlation study); b) non-paired Student's t-test (comparison of measures between sexes); c) nonlinear regression models (nomograms). RESULTS: The liver size presented a progressive growth from the birth up to the age of 7, proportionally lower than the body growth, in correlation with age, height and body weight (r > 0.70). Correlation with the body mass index was not observed (r < 0.11). There was no significant difference in liver size between male and female individuals. CONCLUSION: Liver size was sonographically determined in healthy children under the age of 7 by means of a standardized method, demonstrating a strong correlation with age and anthropometric indicators. Nomograms demonstrate the typical variations of the liver size in the population evaluated with a different growth pattern for each hepatic lobe

Sonographic and hemodynamic findings of schistosomiasis mansoni: doppler sonography assessment in endemic areas

OBJETIVO: Este estudo de campo objetivou identificar as alterações ultrassonográficas e hemodinâmicas indicativas da morbidade da esquistossomose mansônica em áreas endêmicas. MATERIAIS E MÉTODOS: Foram examinados pela ultrassonografia Doppler 554 pacientes esquistossomóticos em três áreas com níveis distintos de endemicidade: baixa endemicidade (n = 109); média endemicidade (n = 255) e alta endemicidade (n = 190). Para o estudo ultrassonográfico foi utilizado o protocolo da Organização Mundial da Saúde (Niamey Working Group, 2000). Pelo Doppler foram avaliados: vasos portais, artérias hepática e esplênica, veias hepáticas e vasos colaterais. RESULTADOS: Houve correlação significativa entre a frequência das alterações ultrassonográficas e o nível de endemicidade das áreas, exceto a hipertrofia do lobo esquerdo. As veias hepáticas apresentaram padrão de fluxo alterado em 23,7% dos casos, alteração esta relacionada à presença e à intensidade de espessamento periportal. A artéria hepática não apresentou alterações nos parâmetros avaliados. Os vasos colaterais foram identificados apenas na área de alta endemicidade. A artéria esplênica apresentou alterações (aumento do calibre, da velocidade e do índice de resistência) mais frequentes na área de alta endemicidade, com diferença significativa entre os grupos. CONCLUSÃO: A ultrassonografia Doppler mostrou-se ferramenta auxiliar importante no estudo da morbidade relacionada à esquistossomose mansônica, contribuindo para definição mais precisa do perfil da doença nas áreas endêmicas.OBJECTIVE: The present field research was aimed at identifying sonographic and hemodynamic findings indicative of the presence of schistosomiasis mansoni in endemic areas. MATERIALS AND METHODS: Doppler sonography was performed in 554 patients with schistosomiasis in three areas with different endemicity levels: low (n = 109), medium (n = 255) and high endemicity (n = 190). The World Health Organization (Niamey Working Group, 2000) protocol was adopted for sonographic evaluation. Doppler study included portal vessels, hepatic and splenic arteries, hepatic veins and collateral vessels. RESULTS: A significant correlation was observed between the frequency of sonographic findings, except for left lobe hypertrophy, and the areas endemicity levels. Altered hepatic veins flow pattern was observed in 23.7% of cases, such abnormality being related to the presence and intensity of periportal thickening. Hepatic arteries did not present any alteration as related to the evaluated parameters. Collateral vessels were identified only in the patients from the high-endemicity area. The splenic artery presented alterations (increase in caliber, flow velocity and resistive index), most frequently in the high-endemicity area, with significant difference between groups. CONCLUSION: Doppler sonography has shown to be a relevant auxiliary tool in the study of the morbidity related to schistosomiasis mansoni, contributing for a more accurate description of the disease profile in endemic areas

Ultra-sonografia dúplex-Doppler na avaliação morfológica e hemodinâmica das artérias aorta e mesentérica cranial em cães

O conhecimento dos sinais normais ao ultra-som Doppler de cada vaso sanguíneo é fundamental na sua identificação. Existem poucos artigos na literatura veterinária que tratam do aspecto normal dos vasos abdominais nos cães. Com o objetivo de verificar a viabilidade técnica da aplicação do US-Doppler na avaliação da aorta abdominal e da artéria mesentérica cranial; vinte cães normais foram submetidos a este exame sem sedação. Foi descrito e avaliado o padrão de mapeamento dúplex-Doppler colorido destes vasos e os resultados comparados com aqueles descritos em literatura. Embora encontradas algumas limitações técnicas, verificamos que o US-Doppler pode ser aplicado com sucesso como meio não invasivo para a detecção de alterações no fluxo sanguíneo mesentérico em cães sem a necessidade de submete-los a contenção química.The knowledge of the normal Doppler signs of each blood vessel is important in their identification. There are few reports in veterinary literature that describe the normal aspect of abdominal blood vessels in dogs. The aim of this paper was verify technical viability of US Doppler use to assessment of the abdominal aorta and cranial mesenteric arteries; twenty clinically normal unsedated dogs were examinated. It was described and assessed characteristic duplex color Doppler spectrum of each blood vessel and the results were compared with that found in literature. Although some technical limitations were found, US Doppler could be successfully used as a noninvasive method to detect mesenteric blood flow changes in dogs without chemical contention

Thyroid ultrasound: state of the art. part 2 - focal thyroid lesions.

Abstract Accurate differentiation of focal thyroid nodules (FTL) and thyroid abnormalities is pivotal for proper diagnostic and therapeutic work-up. In these two part articles, the role of ultrasound techniques in the characterization of FTL and evaluation of diffuse thyroid diseases is described to expand on the recently published World Federation in Ultrasound and Medicine (WFUMB) thyroid elastography guidelines and review how this guideline fits into a complete thyroid ultrasound exam