43 resultados para Ultrasonography, doppler
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
We evaluated 16 pregnant women with gestational age between 20 and 32 weeks in acute severe hypertension which were randomly allocated to receive either hydralazine or labetalol. Blood pressure and Doppler ultrasound parameters from maternal uterine and fetal middle cerebral and umbilical arteries were assessed during acute severe hypertension and after treatment. A significant reduction in systolic and diastolic blood pressure was observed in both groups. A significant change in Doppler parameters was observed only in pregnant women who received hydralazine: an increase in uterine arteries resistance index. We concluded that both drugs were highly effective in reducing blood pressure in these women. Despite the observed increase in resistance index of uterine arteries associated with hydralazine, the use of hydralazine and labetalol were not related to any significant changes in fetal Doppler, which is reassuring about the safety of these drugs when treating acute severe hypertension in pregnancy. (E-mail: wpmartins@gmail.com) (C) 2011 World Federation for Ultrasound in Medicine & Biology.
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Background: Placental insufficiency and fetal growth restriction may lead to fetal hypoxia and acidemia, which result in fetal cardiac injury. Objective: The goal of this study was to compare the levels of fetal cardiac troponin T (cTnT) at birth and fetal Doppler parameters according to fetal gender in pregnancies complicated by placental insufficiency before 34 weeks` gestation. Methods: Between March 2007 and November 2010, singleton pregnancies with placental insufficiency characterized by abnormal umbilical artery Doppler results were prospectively studied. All the patients delivered by cesarean section, and Doppler examinations were performed up to 48 hours before birth. Immediately after delivery, umbilical artery blood samples were obtained for fetal cTnT measurements. Results: Fifty high-risk pregnant women met the study criteria. The study groups were as follows: group 1 consisted of 23 male fetuses (46%) and group 2 consisted of 27 female fetuses (54%). cTnT levels were significantly higher in the group of male fetuses (median, 0.14; range, 0.01-0.85) compared with the group of female fetuses (median, 0.05; range, 0.01-0.27) (P = 0.039). In the group of male fetuses, Doppler results of the ductus venosus assessment revealed values of pulsatility index for veins >= 1.0 in 15 male fetuses (65.2%) and 9 female fetuses (33.3%) (P = 0.032). Conclusions: Fetal gender was associated with cTnT level at birth in pregnancies complicated by placental insufficiency before 34 weeks` gestation, although the Doppler findings did not support gender differences. The fetal cardiac compromise and cardiac injury may be influenced by fetal gender, suggesting differences in the cardiovascular response to fetal hypoxia. (Gend Med. 2011;8:202-208) (C) 2011 Elsevier HS Journals, Inc. All rights reserved.
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Evaluate the distribution and variation of placental vascular indices according to gestational age and placental volume. From March to November 2007, three-dimensional (3D)-power Doppler ultrasound was performed in 295 normal pregnancies from 12 to 40 weeks of gestation. Using the same preestablished settings for all patients, power Doppler was applied to the placenta and placental Volume was obtained by the rotational technique (VOCAL(TM)). The 3D-power histogram was used to determine the placental vascular indices: vascularization index (VI), flow index (FI) and vascularization-flow index (VFI). The placental vascular indices were then plotted against gestational age and placental volume. All placental vascular indices showed constant distribution throughout gestation. A tendency for a reduction in placental vascular indices with increased placental volume was observed, but was only statistically significant when placental FI was considered (p < 0.05). All placental vascular indices estimated by 3D-power Doppler ultrasonography presented constant distribution throughout gestation, despite the increase in placental volume according to gestational age. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Renal diseases are common in older cats. Decreased renal blood flow may be the first sign of dysfunction and can be evaluated by Doppler ultrasound. But previous studies suggest that the resistive index (RI) has a low sensitivity for detecting renal disease. Doppler waveforms of renal and intrarenal arteries demonstrate decreased blood flow before there are any changes in the RI. The purpose of this study was to evaluate the normal Doppler flowmetrics parameters of renal arteries (RAs), interlobar arteries (IAs) and abdominal aorta (AO) in adult healthy, Persian cats. Twenty-five Persian cats (13 females and 12 males with mean age of 30 months and an age range 12-60 months) with normal clinical examinations and biochemical tests and normal systemic blood pressure were given B-mode ultrasonographies in order to exclude all nephropathies, including polycystic kidney disease. All measurements were performed on both kidneys. Both kidneys (n = 50) were examined by color mapping of the renal vasculature. Pulsed Doppler was used to examine both RAs, the IAs at cranial, middle and caudal sites, and the AO. The RI was calculated for all of the vessels. Early systolic acceleration (ESA) of RA and IA was obtained with Doppler spectral analysis. Furthermore, the ratio indices between RA/AO, and IA/RA velocities were calculated. The mean values of peak systolic velocity (PSV) and the diameter for AO were 53.17 +/- 13.46 cm/s and 0.38 +/- 0.08 cm, respectively. The mean RA diameter for all 50 kidneys was 0.15 +/- 0.02 cm. Considering the velocimetric values in both RAs, the mean PSV and RI that were obtained were 41.17 +/- 9.40 cm/s and 0.54 +/- 0.07. The RA had a mean ESA of 1.12 +/- 1.14 m/s(2) and the calculated upper limit of the reference value was 3.40 m/s(2). The mean renal-aortic ratio was 0.828 +/- 0.296. The IA showed PSV and RI values of 32.16 +/- 9.33 cm/s and 0.52 +/- 0.06, respectively. The mean ESA of all IAs was 0.73 +/- 0.61 m/s(2). The calculated upper limit of the reference value was 2.0 m/s(2). The mean renal-interlobar artery ratio was 1.45 +/- 0.57. The RI values obtained in this study were similar to values reported in the literature. Some conditions that lead to a decrease in compliance and to an increase in vascular resistance can affect the Doppler spectral waveforms without changes in RI. To our knowledge, there are no studies that were directed toward to the normal ESA values of the renal vasculature in Persian cats. This study introduced a new ratio between the PSV of the RA and the IA. This index was developed based on the well-known effects of Doppler on the detection of stenosis, regardless of the cause. Further studies are necessary to verify the hemodynamic behavior of this index under pathological conditions in cats as well as the effect of aging, nephropathies and systemic pressure on Doppler velocimetric parameters. (C) 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.
Resumo:
Background. The am of this study was to determine the predictive value for malignancy of microcalcifications determined by ultrasonography in thyroid nodules. Methods. One hundred seventy-seven nodules were prospectively studied by ultrasonography and compared with their fine-needle aspirative biopsy. The association between the presence and type of calcification and cytologic findings was verified through the chi-square test or likelihood ratio. Results. Thirty nodules showed calcification, of which 17 had fine calcifications, 3 had fine and gross calcifications, and 10 had only coarse calcification. Seven (41.18%) of 17 fine calcified nodules were malignant on cytology, 8 (47.06%) were benign, 1 (5,88%) was indeterminate, and 1 was suspect for malignancy. We found statistical significance between the presence of fine calcifications and malignancy (p =.001) and, in the 13 malignant nodule group, 8 (61.50%) had fine calcifications. Conclusion. This study suggests that microcalcifications were highly specific for malignancy and were present in 61% of the malignant nodules. (c) 2008 Wiley Periodicals, Inc.
Resumo:
Objective. To correlate Doppler results with hematological indices at birth in small-for-gestational-age (SGA) fetuses. Design. Prospective study. Setting. Tertiary teaching hospital, Sao Paulo, Brazil. Population. One hundred singleton pregnancies with SGA fetuses of > 27 weeks gestational age. Methods. All women had Doppler velocimetry of the umbilical arteries, middle cerebral artery, and ductus venosus within < 72 hours prior to delivery. After birth, umbilical artery blood was collected for hematological analysis. Main outcome measures. The association between fetal Doppler velocimetry pulsatility index (PI) and some hematological indices. Results. Umbilical artery PI showed a positive correlation with nucleated red blood cell count in the umbilical cord (r = 0.46; p<0.01), and a negative correlation with platelet count (r = -0.53; p<0.01) and white blood cell count (r = -0.42; p<0.01). Middle cerebral artery PI was positively correlated with platelet count (r = 0.43; p<0.01) and white blood cell count (r = 0.38; p<0.01), and was negatively correlated with nucleated red blood cell count (r = -0.39; p<0.01). The ductus venosus pulsatility index showed a positive correlation with nucleated red blood cell count (r = 0.36; p<0.01), and a negative correlation with platelet count (r = -0.37; p<0.01) and white blood cell count (r = -0.26; p<0.01). Conclusion. A significant positive or negative correlation between nucleated red blood cell, platelet and white blood cell counts, and Doppler indices suggests an association between placental insufficiency and the fetal hematological response.
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The aim of this study was to evaluate the arterial and venous blood flow in women who underwent upper limb axillary dissection surgery for the treatment of breast cancer. Sixty women were divided into two groups: group 1 (G1)-30 women who underwent breast surgery with axillary dissection level II or III (55.6 +/- A 8.6 years); group 2 (G2)-control, 30 women with no breast cancer (57.4 +/- A 7.0 years). Blood flow profile was evaluated by a continuous wave ultrasound Doppler device (Nicolet Vascular Versalab SE(A (R))) with an 8 MHz probe. Axillary, brachial arteries and veins, arm circumference, volumes, and the ankle-brachial index (ABI) were examined. Wilcoxon test and Mann-Whitney tests were applied to analyze blood flow velocity intra-group and between G1 and G2, respectively. The G1 results showed no lymphedema and no peripheral arterial disease (ABI > 0.9). Moreover, the mean blood flow velocity of the vessels ipsilateral to the surgery was significantly higher than the contralateral ones for all vessels examined (P < 0.05). The mean velocity of blood flow of the vessels contralateral to surgery was significantly higher than the axillary artery in G2 (P < 0.05). It can be concluded that women who underwent axillary dissection due to breast cancer showed probable stenosis in the arterial and venous axillary and brachial vessels of the upper limb ipsilateral to the surgery, confirmed by the increase of blood flow velocity, and such obstruction might affect the limb contralateral to the operation site.
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Objectives To evaluate the presence of false flow three-dimensional (3D) power Doppler signals in `flow-free` models. Methods 3D power Doppler datasets were acquired from three different flow-free phantoms (muscle, air and water) with two different transducers and Virtual Organ Computer-aided AnaLysis was used to generate a sphere that was serially applied through the 3D dataset. The vascularization flow index was used to compare artifactual signals at different depths (from 0 to 6 cm) within the different phantoms and at different gain and pulse repetition frequency (PR F) settings. Results Artifactual Doppler signals were seen in all phantoms despite these being flow-free. The pattern was very similar and the degree of artifact appeared to be dependent on the gain and distance from the transducer. False signals were more evident in the far field and increased as the gain was increased, with false signals first appearing with a gain of 1 dB in the air and muscle phantoms. False signals were seen at a lower gain with the water phantom (-15 dB) and these were associated with vertical lines of Doppler artifact that were related to PRF, and disappeared when reflections were attenuated. Conclusions Artifactual Doppler signals are seen in flow-free phantoms and are related to the gain settings and the distance from the transducer. In the in-vivo situation, the lowest gain settings that allow the detection of blood flow and adequate definition of vessel architecture should be used, which invariably means using a setting near or below the middle of the range available. Additionally, observers should be aware of vertical lines when evaluating cystic or liquid-containing structures. Copyright (C) 2010 ISUOC. Published by John Wiley & Sons, Ltd.
Resumo:
The objective of the present study was to evaluate fetal biometry, Doppler values, and perinatal outcomes in pregnant women with antiphospholipid syndrome treated with acetylsalicylic acid and heparin. Twenty-five pregnant women with antiphospholipid syndrome using 100 mg/day acetylsalicylic acid and 5,000 IU heparin every 12 h were evaluated in this prospective observational study. Ultrasonography was performed between 24 and 38 weeks of gestational age to assess estimated fetal weight, placental thickness, amniotic fluid index, fetal biophysical profile and Doppler evaluation of maternal uterine arteries, and fetal middle cerebral and umbilical arteries. Data regarding Apgar score, gender, delivery mode, and birth weight and length were recorded after birth. The observed values for ultrasonographic assessment and perinatal outcomes were not very different from the expected values for normal pregnancies. The birth weight was 2863.3 +/- A 737.7 g (mean +/- A SD) and length was 46.8 +/- A 4.2 cm. Only one newborn (4%) had the 1-min Apgar score < 7 and all had the 5-min Apgar score > 7. Gestational and perinatal evaluation of pregnant women with antiphospholipid syndrome using both acetylsalicylic acid and heparin was reassuring.
Resumo:
The objective of this study was to describe multiple Doppler ultrasound parameters of ductus venosus and inferior vena cava in fetuses at gestational ages ranging from 22 to 38 weeks. In this prospective observational study, Doppler ultrasound exams were performed in 45 healthy fetuses at 22, 26, 34, and 38 weeks. Maximum venous velocity, minimum venous velocity, venous pulsatility index, and venous acceleration time (VAT) (defined as the time between minimum and maximum venous velocity) were evaluated at those gestational periods. Increase in the velocities and decrease in the pulsatility index were observed in these vessels throughout gestational age. The VAT increased with gestational age. The VAT, a Doppler parameter still not described elsewhere, increased during pregnancy could be related to a longer period of time needed to fill the atrium in bigger hearts. In this study, we provide reference values for VAT in healthy fetuses.
Resumo:
The aim of this study was to investigate the agreement between diagnoses of calcified atheroma seen on panoramic radiographs and color Doppler images. Our interest stems from the fact that panoramic images can show the presence of atheroma regardless of the level of obstruction detected by color Doppler images. Panoramic and color Doppler images of 16 patients obtained from the archives of the Health Department of the city of Valença, RJ, Brazil, were analyzed in this study. Both sides of each patient were observed on the images, with a total of 32 analyzed cervical regions. The level of agreement between diagnoses was analyzed using the Kappa statistics. There was a high level of agreement, with a Kappa value of 0.78. In conclusion, panoramic radiographs can help detecting calcifications in the cervical region of patients susceptible to vascular diseases predisposing to myocardial infarction and cerebrovascular accidents. If properly trained and informed, dentists can refer their patients to a physician for a cardiovascular evaluation in order to receive proper and timely medical treatment.
Resumo:
OBJECTIVES: Causes may be found in most cases of acute pancreatitis, however no etiology is found by clinical, biological and imaging investigations in 30% of these cases. Our objective was to evaluate results from endoscopic ultrasonography (EUS) for diagnosis of gallbladder microlithiasis in patients with unexplained (idiopathic) acute pancreatitis. METHODS: Thirty-six consecutive non-alcoholic patients with diagnoses of acute pancreatitis were studied over a five-year period. None of them showed signs of gallstones on transabdominal ultrasound or tomography. We performed EUS within one week of diagnosing acute pancreatitis. Diagnosis of gallbladder microlithiasis on EUS was based upon findings of hyperechoic signals of 0.5-3.0 mm, with or without acoustic shadowing. All patients (36 cases) underwent cholecystectomy, in accordance with indication from the attending physician or based upon EUS diagnosis. RESULTS: Twenty-seven patients (75%) had microlithiasis confirmed by histology and nine did not (25%). EUS findings were positive in twenty-five. Two patients had acute cholecystitis diagnosed at EUS that was confirmed by surgical and histological findings. In two patients, EUS showed cholesterolosis and pathological analysis disclosed stones not detected by EUS. EUS diagnosed microlithiasis in four cases not confirmed by surgical treatment. In our study, sensitivity, specificity and positive and negative predictive values to identify gallbladder microlithiasis (with 95% confidence interval) were 92.6% (74.2-98.7%), 55.6% (22.7-84.7%), 86.2% (67.4-95.5%) and 71.4% (30.3-94.9%), respectively. Overall EUS accuracy was 83.2%. CONCLUSIONS: EUS is a very reliable procedure to diagnose gallbladder microlithiasis and should be used for the management of patients with unexplained acute pancreatitis. This procedure should be part of advanced endoscopic evaluation.
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Left ventricular diastolic dysfunction plays an important role on heart failure progression. In order to obtain additional reference values of left ventricular diastolic parameters and investigate influence of common variables, peak E wave (peak E), peak A wave (peak A), E/A ratio (E/A), E wave deceleration time (EDT) and isovolumic relaxation time (IRVT) were studied in 40 clinically healthy dogs, by pulsed wave Doppler. The following values were obtained: peak E = 0.747 ± 0.117 m/s, peak A = 0.487 ± 0.062 m/s, E/A = 1.533 ± 0.198, EDT = 88.7 ± 9.2 ms and IRVT = 0.080 ± 0.009 s. Some parameters were influenced by heart rate (peak E, peak A and IRVT), by age (peak A and E/A) and by body weight (TRIV). Gender influence was absent. Values obtained can be used as reference for canine specimens but its interpretation should consider on the influence of related variables.
Resumo:
Foram comparados dois métodos não-invasivos de medida da pressão arterial, o Doppler vascular e o oscilométrico, com o objetivo de estabelecer parâmetros que possam auxiliar no diagnóstico seguro da hipertensão arterial. Para tal, foram utilizados 45 cães, machos e fêmeas, distribuídos em três grupos de acordo com o peso, pequeno, médio e grande porte. Em cada animal, procedeu-se a mensuração por meio do Doppler vascular e, em seguida, do oscilométrico. Na obtenção da pressão arterial sistólica, não houve diferença entre os métodos nos três grupos de animais, porém, na obtenção da pressão arterial diastólica, houve diferença estatística entre o Doppler vascular e o oscilométrico nos grupos de animais de pequeno e médio porte. Pôde-se concluir que valores confiáveis de pressão sistólica podem ser obtidos tanto por meio do Doppler vascular quanto do oscilométrico. Os valores da pressão arterial diastólica obtidos pelos dois métodos não se correlacionam, principalmente nos animais de pequeno e médio porte.
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Avaliaram-se com Doppler pulsátil os fluxos das valvas aórtica (AO) e pulmonar (Pul) por meio de análise qualitativa (presença de regurgitações valvares e características do espectro avaliado) e quantitativa, com obtenção de parâmetros ecocardiográficos como velocidades máxima (V. Max.) e média (V. Me.), integral de velocidade (VTI), tempo de aceleração (TA) e ejeção (TE), de 30 cães considerados clinicamente sadios por meio de exames físico, laboratoriais, eletrocardiográfico, ecocardiográfico (modos uni e bidimensional), radiográfico de tórax e mensuração da pressão arterial sistêmica. Obtiveram-se os seguintes resultados para os referidos parâmetros: V.max. AO= 1,22± 19,38m/s; V. Me. AO= 0,72± 0,08m/s; VTI AO= 0,14± 0,02m; TA AO= 38,80± 11,29ms; TE AO= 197,90± 24,77ms; V. Max. Pul= 0,95± 0,18m/s; V. Me. Pul= 0,63± 0,10m/s; VTI Pul= 0,13± 0,02m; TA Pul= 70,97± 18,87ms; TE Pul= 203,70± 28,98ms. Em apenas três animais observou-se regurgitação pulmonar. Alguns parâmetros apresentaram correlação negativa com a variável freqüência cardíaca (VTI AO, TE AO, VTI Pul, TA Pul, TE Pul); outros correlação positiva com a variável peso (VTI AO, TA AO, TE AO, VTI Pul, TE Pul,) e não se observou influência da variável sexo na maioria dos parâmetros avaliados. Na comparação entre os dois fluxos, observaram-se V. Max. AO e V. Me. AO maiores que V. Max. Pul. e V. Me. Pul., respectivamente, VTI AO maior que VTI Pul, e TA AO menor que TA Pul.