Pulsed Doppler Ultrasonography Research Articles

B-mode ultrasonography and ecobiometric parameters for assessment of embryonic and fetal development in sheep

The aim in this study was to evaluate the maternal-fetal development during physiological gestation in sheep by means of ultrasonography and to predict the gestational age by mathematical formulae. Thirty Santa Inês sheep were included. Evaluations were performed weekly from the 3rd to 21st gestational week. The Shapiro test was used to determine normality of the data, and Spearman test was used for determining correlations of real or transformed measurements as gestation advanced. If there was a significant difference detected, variable adjustments and gestational weeks were tested using regression models. Significance level was set at 5% and the results presented as mean ± SD. Principal components analysis (PCA) was used for data clustering and graphic analysis. The gestational vesicle, abdominal, thoracic, biparietal, ocular orbit, and placentome diameters; and the lengths of crown-to-rump, nuchal to snout, scapula, humerus, radius, metacarpus, femur, tibia, metatarsal, heart length, heart width and kidneys were measured. Using pulsed Doppler ultrasonography, heart rate (HR) was obtained. The greatest coefficients of determination (r²) were obtained for the biparietal diameter (BPD; 96.5%) and metacarpus length (MCAR; 93%), followed by the abdominal diameter (AD; 91.7%) and heart width (HTW; 90.2%). The PCA analysis indicated graphically that at week 8 to 9, there was no significant change related to technique, whereas, at weeks 19, 20, and 21 a decrease in growth was observed, with the greatest data variability at week 19. Ultrasonographic assessments indicated there were significant correlations between developmental stages of all maternal-fetal structures and the gestational age, which can be used as reference values for gestational age assessments and detection of development abnormalities.

Preliminary experience with epidural and perineural catheter localization with pulsed wave Doppler ultrasonography.

Various methods for peripheral nerve and epidural catheter location assessment exist, with varying degrees of ease of use, utility, and accuracy. Pulsed wave Doppler (PWD) evaluates the presence of fluid flow and is possible modality to assess the location of a percutaneously inserted perineural catheter. A retrospective chart review was conducted in which PWD ultrasonography was used to confirm the position of nerve catheters for regional anesthesia. Data was collected to assess 24-hour postoperative pain scores, opioid consumption, complications, and the incidence of catheter replacement. Eighty-six patients were included; average age was 58 years and a 27% incidence of chronic pain. These catheters were left in place based on the PWD images. Three catheters failed and a total of 16 catheters were repositioned. In the first 24 hours average pain scores ranges between 3.5 to 5.9 and median postoperative opioid consumption range was 11.3 mg to 60.8 mg. For epidural catheters, PWD changes were more obvious with air injection and there was only one episode of hemodynamic instability. Our preliminary experience with PWD ultrasonography suggests that they may offer the ability to selectively assess flow at different locations to identify the proper location of epidural and perineural catheters. Future randomized, controlled investigations are warranted to further evaluate the effectiveness and safety of this modality.

Effects of medetomidine on intra-renal arteries resistive and pulsatility indices in clinically normal adult domestic shorthair cats.

The aim of this study was to determine the effects of intramuscular injection of medetomidine on intra-renal arteries resistive and pulsatility indices by duplex Doppler ultrasonography in clinically normal adult domestic shorthair cats. For this purpose, twenty-six neutered adult healthy domestic shorthair cats (13 females and 13 males) were evaluated. B-mode, color Doppler and pulsed wave Doppler ultrasonography of right and left kidneys were performed to record the resistive index (RI) and pulsatility index (PI) of intra-renal arteries. To minimize statistical errors, the mean RI and PI were determined for each kidney by averaging three waveforms from the intra-renal arteries. Twenty-four hr later, the cats were sedated by 0.04 mg kg-1 intramuscular administration of medetomidine. All the Doppler measurements were repeated 15 min after drug administration. Mean ± standard deviation )SD( of PI and RI of the intra-renal arteries before administration of intramuscular medetomidine were 1.03 ± 0.08 and 0.61 ± 0.02, respectively. Fifteen min after medetomidine administration, the mean ± SD of PI and RI values were 1.04 ± 0.08 and 0.61 ± 0.02, respectively. Significant differences were not detected in mean PI and RI values before and 15 min after drug administration. Our findings showed that intramuscular administration of medetomidine does not cause significant hemodynamic changes in the intra-renal arteries after 15 min.

Sonographic Evaluation of Liver Hemodynamic Indices in Overweight and Obese Dogs.

BackgroundHepatic circulatory disturbances have been associated with obesity and fatty liver in humans. In the veterinary literature, however, there is limited information regarding the effects of different body condition scores (BCS) on liver hemodynamic indices in dogs.ObjectivesTo investigate the influence of BCS on liver hemodynamic indices.AnimalsFifty‐three client‐owned dogs of various breeds were included.MethodsProspective observational study. Dogs were divided into 3 BCS groups using a 5‐point scale: G1 – 12 ideal dogs, G2 – 21 overweight dogs, G3 – 20 obese dogs. Mean portal velocity (MPV), portal blood flow volume (PBFV), portal congestion index (PCI), hepatic artery resistivity index (HARI), and hepatic vein (HV) spectral wave were obtained by pulsed Doppler sonography. Alkaline phosphatase (ALP), gamma‐glutamyl transferase (GGT), and alanine aminotransferase (ALT) activities were determined. Liver enzymes activities and liver hemodynamic indices were compared among groups.ResultsObese dogs had lower MPV, higher percentage of abnormal hepatic vein spectral wave and higher median ALP activity than did ideal dogs (P < 0.05). Overweight and obese dogs had lower PBFV than ideal dogs (P < 0.01). Overweight dogs had higher median GGT activity than ideal dogs (P < 0.05). No difference was observed for PCI, HARI and median ALT activity among the groups.Conclusions and Clinical ImportanceObesity was associated with changes in portal vein indices and in HV spectral wave. These changes were accompanied by significant differences in some liver enzymes activities and could be a sign of early liver disease.

パルスドプラによるFFT解析が治療方針決定に有用であった早期の小腸絞扼状態と判断しえた症例—癒着性イレウス，ヘルニア嵌頓例との比較も含めて—

パルスドプラによるFFT解析が治療方針決定に有用であった早期の小腸絞扼状態と判断しえた症例—癒着性イレウス，ヘルニア嵌頓例との比較も含めて—

A Contrast-Enhanced Ultrasonographic Study About the Impact of Long-term Exercise Training on Mammary Tumor Vascularization.

This study aimed to evaluate the impact of long-term exercise training on the vascularization of rat mammary tumors. Female rats were divided into 4 groups: N-methyl-N-nitrosourea (MNU) treated sedentary, MNU treated exercised, control sedentary, and control exercised. Tumor development was induced in the MNU groups by MNU administration. Exercised groups were trained for 35 weeks. Tumor vascularization was evaluated by pulsed Doppler and contrast-enhanced ultrasonography. The pulsatility and resistive indices were slightly higher in the MNU sedentary group (P > .05). Mammary tumors mainly had centripetal and heterogeneous enhancement of the contrast, clear margins, and the presence of penetrating vessels. The MNU exercised group had a lower arrival time and time to peak and higher peak intensity, wash-in, and wash-out (P > .05). The area under the curve was similar between groups (P > .05). The contrast-enhanced ultrasonographic study did not detect differences in mammary tumor vascularization between MNU sedentary and MNU exercised groups previously detected by power Doppler imaging, B-flow imaging, and immunohistochemistry.

Differential approach to the evaluation of right ventricular systolic function by pulsed wave Doppler ultrasound

A method for diagnostics of systolic function of the right ventricle of the heart in patients with cardiovascular disease is proposed. Its application expands possibilities for detecting disorders of the discharge RV function using a conventional pulsed wave Doppler ultrasonography.

Association of Placental Jets and Mega-Jets With Reduced Villous Density

Spiral arteries (SAs) lie at the interface between the uterus and placenta, and supply nutrients to the placental surface. Maternal blood circulation is separated from the fetal circulation by structures called villous trees. SAs are transformed in early pregnancy from tightly coiled vessels to large high-capacity channels, which is believed to facilitate an increased maternal blood flow throughout pregnancy with minimal increase in velocity, preventing damage to delicate villous trees. Significant maternal blood flow velocities have been theorized in the space surrounding the villi (the intervillous space, IVS), particularly when SA conversion is inadequate, but have only recently been visualized reliably using pulsed wave Doppler ultrasonography. Here, we present a computational model of blood flow from SA openings, allowing prediction of IVS properties based on jet length. We show that jets of flow observed by ultrasound are likely correlated with increased IVS porosity near the SA mouth and propose that observed mega-jets (flow penetrating more than half the placental thickness) are only possible when SAs open to regions of the placenta with very sparse villous structures. We postulate that IVS tissue density must decrease at the SA mouth through gestation, supporting the hypothesis that blood flow from SAs influences villous tree development.

Evaluation of the ureteral jet in dogs by using color Doppler ultrasonography.

Ureteral jets are the result of a forceful ejection of urine from the vesicoureteral junction into the urinary bladder. By using color Doppler ultrasonography (US), we aimed to identify distinct ureteral jets in dogs, provide insight into ureteral obstruction, and facilitate study of urodynamics and vesicoureteric sphincter function via pulsed Doppler US. Color Doppler US was applied to detect urinary flow from the right ureteral orifices in eight healthy beagles. Under anesthesia, 0.9% saline (2.5 mL/kg/h) and furosemide (0.5 mg/kg) were administered intravenously to assist in detection of distinct ureteral jets and examine their frequency, velocity, duration, and waveform. In all dogs, ureteral jets were visualized under diuresis and anesthesia within 2 to 5 min (mean 3.57 ± 0.90 min) of the furosemide injection. Mean frequency, peak velocity, and duration of right ureteral jets in seven dogs in whom six ureteral jet waveform patterns were identified were 9.86 ± 3.09 jets/min, 34.07 ± 10.02 cm/sec, and 2.82 ± 1.08 sec, respectively. During the 10 min period starting 10 min after the initial jet appeared, only three waveforms were identified. Color Doppler US of ureteral jets may aid in assessing vesicoureteric sphincter function and ureteral abnormalities, such as ureteral obstruction, in dogs.

B-Mode and pulsed Doppler sonography of kidney in healthy sheep according to age

Abstract: There is no standardization in the literature of kidney length in sheep at different ages, as there are few studies about the access with the Doppler triplex ultrasound for the renal vascularization in this species. Eighty healthy sheep of three age groups of Ile de France and White Dorper breed were used: 20 lambs, 30 yearlings and 30 adults (8 rams and 22 ewes). Renal healthiness of the animals was confirmed by serum biochemical tests of urea and creatinine, and by observation of renal architecture with conventional ultrasound, besides measurement of vital parameters. A portable ultrasound (My LabTM30 Vet Gold Esaote®, Esaote Healthcare) device was used, with a convex transducer with 3.5MHz frequency. After identification of the kidneys in two-dimensional mode, the measurement of length in the sagittal section was performed in all sheep (n=80). Then color Doppler was activated for visualization of renal and interlobar arteries of the right kidney, and the resistivity index (RI) of the yearlings (n=30) and ewes (n=22) was measured. Biochemical tests remained within normal limits and renal architecture was preserved. The values of the right and left renal length were different between the groups, increasing with age (4.34cm and 4.31cm in lambs; 6.08cm and 6.23cm in yearlings; 7.57cm and 7.37cm in adults, respectively). Median values of RI of the renal artery were statistically different (p&lt;0.05) between the groups of yearlings (0.57) and ewes (0.52). The median RI of the interlobar artery was similar in yearlings (0.58) and ewes (0.54).

Acute effect of oral sensation of sweetness on celiac artery blood flow and gastric myoelectrical activity in humans.

Little is known about the effect of sweet taste stimulus on gastrointestinal motility and splanchnic blood flow. We examined whether gastric myoelectrical activity and/or celiac artery blood flow (CABF), which perfuses the stomach, are increased following an oral sensation of sweetness. After overnight fasting, 11 subjects rested for 5min and sipped, but not swallowed, one of four solutions for 1min. The fluid was then spat out, and subjects remained at rest for a further 10min. Fluids were approximately 15ml of three glucose solutions (4, 16, or 48%) or distilled water. Subjects completed trials with all four solutions in a randomized order. During each trial, gastric myoelectrical activity and CABF were continuously measured using electrogastrography and pulsed Doppler ultrasonography, respectively. None of the four solutions affected gastric myoelectrical activity. CABF was significantly increased after oral stimuli by all three glucose solutions, but not by water. There were no significant differences in the increments in CABF among the three glucose solutions. These results suggest that a sweet taste stimulus above a certain level of intensity acutely increases CABF during cephalic phase, without augmentation of gastric myoelectrical activity.

超音波パルスドプラによるストレッチング効果の血行動態解析

要旨：本研究の目的は，腓腹筋に対するストレッチングが血行動態に及ぼす影響を生理学的に明らかにすることである。対象は，健常男子学生40名40肢右脚とした。方法は，ストレッチングを課す条件（ストレッチ条件）とストレッチングを課さない条件（control 条件）で，超音波を用いて，血管径および血流速度から膝窩動脈の血行動態を評価し，条件間およびストレッチング前後で比較検討した。結果は，条件間の血管径に有意差はみられないが，血流速度においてストレッチング前に比べストレッチング後は，有意な速度上昇がみられた。本結果から，ストレッチングは血流速度を上昇させるため，栄養する筋血流量を一時的に増加させる可能性が示唆された。

The Cephalic Phase Responses of Celiac Artery Blood Flow and Gastric Motility to Oral Sweet Taste

In humans little is known as to whether oral sensation of sweetness elicits any changes of splanchnic blood flow and gastrointestinal motility. The aim of this study, therefore, was to examine whether any effect of different oral sweet stimuli on celiac artery blood flow (CABF, which predominantly perfuses the stomach) and gastric motility occur. The oral stimulation was performed as follows: Subjects sipped a taste solution without swallowing. The fluid was then spat out, and subjects remained for post‐stimulation recording. During the protocol, CABF and gastric motility were continuously measured using pulsed Doppler ultrasonography and electrogastrography (EGG), respectively. In the experiment 1, 18% glucose (Glu), 18% maltodextrin (Mal) and mineral water (MW) were used for orosensory stimulation. Whereas all solutions had no effect on gastric motility, the stimulus by Glu (i.e. sweet taste solution) increased CABF acutely (p&lt;0.05), but those by Mal and MW (i.e. non‐sweet taste solutions) did not. Accordingly, as the experiment 2, different concentrations of glucose (0, 4, 16, and 48%) were adopted to examine the dose‐response relationship of oral sensation of sweetness on CABF. While three glucose solutions, excepting 0%, increased the CABF (16, 21, and 23% from baseline, respectively; p&lt;0.05), there were no significant differences among them. These results suggest that oral sensation of sweetness acutely increases CABF without augmentation of gastric motility, while it is not certain that the CABF is increased proportionally with the sweet taste intensity.

Evaluation of Fetal Pulmonary Veins During Early Gestation by Pulsed Doppler Ultrasound: A Feasibility Study

AbstractCongenital heart disease (CHD) is the leading cause of infant mortality. Nevertheless, routine prenatal ultrasound only detects 30 %–50 % of CHD cases. Therefore, emphasis should be placed on early predictors of CHD that allow physicians to timely refer high-risk patient to specialized fetal echocardiography, in order to maximize chances of improved outcomes. The fetal venous system has been the focus of attention as a marker of heart function. Yet, there exist inconsistent data about the acquisition of pulmonary venous flow in early pregnancy. This study aims to determine the feasibility of fetal pulmonary venous flow acquisition in early pregnancy, and the association between pulmonary vein (A-wave) flow reversal and the presence of CHD. Total of 211 consecutive pregnant women, between 12 and 15 weeks of gestation, underwent routine obstetric ultrasound along with basic fetal echocardiography including fetal pulmonary venous flow assessment. The pulmonary venous flow velocity waveforms were acquired by either Doppler or Doppler plus enhance flow technique based on equipment availability. All the cases were re-evaluated by specialized fetal echocardiography during late pregnancy to identify congenital heart anomalies. The acquisition of fetal pulmonary vein, between 12 and 15 weeks of gestation, was successfully accomplished in 87.7 % of cases. Five out of seven fetuses with end-diastolic (A-wave) pulmonary venous flow reversal were associated with confirmed cardiac anomaly. In this pilot study, pulmonary venous (A-wave) flow reversal was associated with cardiac anomalies in 86.8 % of cases (p = 0.001). This pilot study proposes that Doppler interrogation of fetal pulmonary vein flow during early pregnancy is feasible. Furthermore, the presence of pulmonary vein (A-wave) reversal might represent a marker of major cardiac anomalies. Further investigation is needed to confirm these findings.

Colour-coded and Pulsed Doppler Sonography of Testicular and Prostatic Artery in Dog

The present study was conducted to measure the various indices of Testicular and Prostatic Artery in Dogs at Different Age using Colour-coded and pulsed Doppler Sonography.

Reversed portal flow: Clinical influence on the long-term outcomes in cirrhosis.

To elucidate the natural history and the longitudinal outcomes in cirrhotic patients with non-forward portal flow (NFPF). The present retrospective study consisted of 222 cirrhotic patients (120 males and 102 females; age, 61.7 ± 11.1 years). The portal hemodynamics were evaluated at baseline and during the observation period using both pulsed and color Doppler ultrasonography. The diameter (mm), flow direction, mean flow velocity (cm/s), and mean flow volume (mL/min) were assessed at the portal trunk, the splenic vein, the superior mesenteric vein, and the collateral vessels. The average values from 2 to 4 measurements were used for the data analysis. The portal flow direction was defined as follows: forward portal flow (FPF) for continuous hepatopetal flow; bidirectional flow for to-and-fro flow; and reversed flow for continuous hepatofugal flow. The bidirectional flow and the reversed flow were classified as NFPF in this study. The clinical findings and prognosis were compared between the patients with FPF and those with NFPF. The median follow-up period was 40.9 mo (range, 0.3-156.5 mo). Twenty-four patients (10.8%) demonstrated NFPF, accompanied by lower albumin level, worse Child-Pugh scores, and model for end-stage liver disease scores. The portal hemodynamic features in the patients with NFPF were smaller diameter of the portal trunk; presence of short gastric vein, splenorenal shunt, or inferior mesenteric vein; and advanced collateral vessels (diameter > 8.7 mm, flow velocity > 10.2 cm/s, and flow volume > 310 mL/min). The cumulative incidence rates of NFPF were 6.5% at 1 year, 14.5% at 3 years, and 23.1% at 5 years. The collateral vessels characterized by flow velocity > 9.5 cm/s and those located at the splenic hilum were significant predictive factors for developing NFPF. The cumulative survival rate was significantly lower in the patients with NFPF (72.2% at 1 year, 38.5% at 3 years, 38.5% at 5 years) than in those with forward portal flow (84.0% at 1 year, 67.8% at 3 years, 54.3% at 5 years, P = 0.0123) using the Child-Pugh B and C classifications. NFPF has a significant negative effect on the prognosis of patients with worse liver function reserve, suggesting the need for careful management.

フロープロファイル法およびパルスドプラ法による上腕動脈推定血流量と超音波希釈法によるarteriovenous fistula (AVF) 血流量との比較

われわれは濃度希釈法による動静脈瘻 (AVF) 推定血流量 (eAVF-FV) と, フロープロファイル法 (FP法) およびパルスドプラ法 (PD法) による上腕動脈推定血流量 (eBA-FV) の測定値を比較検討した. 維持血液透析17例に対し透析前にアロカメディカル社ProSoundα7 (以下A7), GEヘルスケア社LOGIQ Book XP (以下LB) により, eBA-FVおよびAVF血流途絶下のAVF側eBA-FV (pBA-FV), AVF反対側肢のeBA-FV (cBA-FV) を, さらに透析中Transonic Systems社HD02により濃度希釈法でeAVF-FVを各3回測定し, 再現性, 平均値, 誤差率 (誤差率=[|eBA-FV-eAVF-FV|]/eAVF-FV×100) を検討した. eAVF-FVは155～1,045mL/min (566±322mL/min) でA7-FP法とA7-PD法のeBA-FVと有意差はなく, LB-PD法は有意に高値だった. 誤差率はA7-FP法で39±42%, A7-PD法で47±45%で両者間に有意差はなく, LB-PDは83±59%で他2者より有意に大きく (p=0.025), pBA-FV, cPA-FV補正による有意の変化はなかった. 超音波による血流量測定値は, 誤差率を勘案すれば臨床的に有用と思われる.

Doppler Ultrasonographic Estimation of Renal Resistive Index in Horse: Comparison Between Left and Right Kidneys

The renal resistive index (RI) is the ratio of the difference between maximum and minimum (end diastolic) flow velocity derived from the Doppler spectrum of intrarenal (segmental/interlobar) arteries. It is a good indicator for acute renal disease, acute tubular necrosis, and renal obstruction. To our knowledge, no reports are available about the values of renal RI in unsedated horses. The aim of this study was to establish a normal reference range (mean ± standard error) and to assess the reliability of the renal RI obtained using transabdominal ultrasonography in unsedated healthy horses. Thirteen conscious Thoroughbred horses judged healthy based on physical examination, complete blood count, biochemical profile, urinalysis, and ultrasonography were included. The peak-systolic and end-diastolic velocities of interlobar and arcuate arteries were measured. Intrarenal arteries were scanned by pulsed Doppler ultrasonography to calculate RI. The comparison of left versus right kidneys was analyzed with analysis of covariance (ANCOVA) procedure. Significant differences (P < .05) for the RI values were observed between left and right kidneys in the geldings (left 0.50 vs. right 0.56) and mares (left 0.50 vs. right 0.57) and were observed between left and right kidneys in trained (left 0.52 vs. right 0.55) and untrained horses (left 0.48 vs. right 0.58). The renal RI has not been modified by sex.

Respiratory sinus arrhythmia stabilizes mean arterial blood pressure at high-frequency interval in healthy humans.

Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.

Systolic Phase Detection from Pulsed Doppler Ultrasound Signalusing EMD-DHT based Approach

A new algorithm is developed to detect cardiac cycle’s systolic phase from the underwater construction workersDopplerultrasound signal. The method is on the basis of empirical mode decomposition (EMD), in combination with the discrete Hilbert transform (DHT). The EMD combined with DHT constitutes the Hilbert spectrum (HS) which is a fine-resolution time-frequency-energy representation of a nonstationary signal. Here EMD is used to calculate the intrinsic mode functions (IMFs), and thenthe DHT is employed to the IMFs to obtain three instantaneous components- frequency, amplitude and phase. Therefore, the HS is constructed from the normalized instantaneous frequencies and weighted sum of instantaneous amplitudes of the IMFs at the frequency bins. A new representation and interpretation of high graded signal is given to the time-frequency-energy distribution using HS. Finally systolic phase detection performance is evaluated in terms of sensitivity and positive predictivity.