Fetal cardiac filling and ejection time fractions by pulsed-wave Doppler: reference ranges and potential clinical application.

OBJECTIVES: Fetal cardiac function can be evaluated using a variety of parameters. Among these, cardiac cycle time-related parameters, such as filling time fraction (FTF) and ejection time fraction (ETF), are promising but rarely studied. We aimed to report the feasibility and reproducibility of fetal FTF and ETF measurements using pulsed-wave Doppler, to provide reference ranges for fetal FTF and ETF, after evaluating their relationship with heart rate (HR), gestational age (GA) and estimated fetal weight (EFW), and to evaluate their potential clinical utility in selected fetal conditions. METHODS: This study included a low-risk prospective cohort of singleton pregnancies and a high-risk population of fetuses with severe twin-twin transfusion syndrome (TTTS), aortic stenosis (AoS) or aortic coarctation (CoA), from 18 to 41 weeks' gestation. Left ventricular (LV) and right ventricular inflow and outflow pulsed-wave Doppler signals were analyzed, using valve clicks as landmarks. FTF was calculated as: (filling time/cycle time) × 100. ETF was calculated as: (ejection time/cycle time) × 100. Intraclass correlation coefficients (ICC) were used to evaluate the intra- and interobserver reproducibility of FTF and ETF measurements in low-risk fetuses. The relationships of FTF and ETF with HR, GA and EFW were evaluated using multivariate regression analysis. Reference ranges for FTF and ETF were then constructed using the low-risk population. Z-scores of FTF and ETF in the high-risk fetuses were calculated and analyzed. RESULTS: In total, 602 low-risk singleton pregnancies and 54 high-risk fetuses (nine pairs of monochorionic twins with severe TTTS, 16 fetuses with AoS and 20 fetuses with CoA) were included. Adequate Doppler traces for FTF and ETF could be obtained in 95% of low-risk cases. Intraobserver reproducibility was good to excellent (ICC, 0.831-0.905) and interobserver reproducibility was good (ICC, 0.801-0.837) for measurements of all timing parameters analyzed. Multivariate analysis of FTF and ETF in relation to HR, GA and EFW in low-risk fetuses identified HR as the only variable predictive of FTF, while ETF was dependent on both HR and GA. FTF increased with decreasing HR in low-risk fetuses, while ETF showed the opposite behavior, decreasing with decreasing HR. Most recipient twins with severe TTTS showed reduced FTF and preserved ETF. AoS was associated with decreased FTF and increased ETF in the LV, with seemingly different patterns associated with univentricular vs biventricular postnatal outcome. The majority of fetuses with CoA had FTF and ETF within the normal range in both ventricles. CONCLUSIONS: Measurement of FTF and ETF using pulsed-wave Doppler is feasible and reproducible in the fetus. The presented reference ranges account for associations of FTF with HR and of ETF with HR and GA. These time fractions are potentially useful for clinical monitoring of cardiac function in severe TTTS, AoS and other fetal conditions overloading the heart. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Ultrasound perfusion imaging in acute middle cerebral artery infarction predicts outcome.

BACKGROUND AND PURPOSE: Initial reports indicate that transcranial harmonic imaging after ultrasound contrast agent bolus injection (BHI) can detect cerebral perfusion deficits in acute ischemic stroke. We evaluated parametric images of the bolus washout kinetics. METHODS: Twenty-three patients with acute internal carotid artery infarction were investigated with perfusion harmonic imaging after SonoVue bolus injection < or =40 hour after the onset of symptoms. The findings were compared with those of cranial computed tomography (CCT) and clinical course 4 months after stroke. RESULTS: Images of pixel-wise peak intensity (PPI) and time to peak intensity could be calculated for all patients. Spearman rank correlations of r=0.772 (P<0.001) and r=0.572 (P=0.008) between area of PPI signal decrease and area of infarction in the follow-up CCT as well as outcome after 4 months were obtained, respectively. CONCLUSIONS: In the early phase of acute ischemic stroke, BHI after SonoVue bolus injection is a useful ultrasound tool for analyzing cerebral perfusion deficits at the patient's bedside. BHI data correlate with the definite area of infarction and outcome after 4 months.

Peak velocity overestimation and linear-array spectral Doppler.

Ultrasound instruments are used to evaluate blood flow velocities in the human body. Most clinical instruments perform velocity calculations based on the Doppler principle and measure the frequency shift of a reflected ultrasound beam. Doppler-only instruments use single-frequency, single-crystal transducers. Linear- and annular-array multiple-crystal transducers are used for duplex scanning (simultaneous B-mode image and Doppler). Clinical interpretation relies primarily on determination of peak velocities or frequency shifts as identified by the Doppler spectrum. Understanding of the validity of these measurements is important for instruments in clinical use. The present study examined the accuracy with which several ultrasound instruments could estimate velocities based on the identification of the peak of the Doppler spectrum, across a range of different angles of insonation, on a Doppler string phantom. The string was running in a water tank at constant speeds of 50, 100, and 150 cm/sec and also in a sine wave pattern at 100- or 150-cm/sec amplitude. Angles of insonation were 30, 45, 60, and 70 degrees. The single-frequency, single-crystal transducers (PC Dop 842, 2-MHz pulsed-wave, 4-MHz continuous-wave) provided acceptably accurate velocity estimates at all tested velocities independent of the angle of insonation. All duplex Doppler instruments with linear-array transducers (Philips P700, 5.0-MHz; Hewlett-Packard Sonos 1000, 7.5-MHz; ATL Ultramark 9 HDI, 7.5-MHz) exhibited a consistent overestimation of the true flow velocity due to increasing intrinsic spectral broadening with increasing angle of insonation.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of carotid artery stenosis with various Doppler velocity parameters.

PURPOSE: To assess the Doppler indices best suited for detecting a stenosis of the internal carotid artery. MATERIAL AND METHOD: 358 patients (234 men, 124 women, mean age 59 years, range 25-83 years) were examined via duplex carotid sonography (US) and arteriography. Flow indices and B-mode real-time results of stenoses were compared with arteriographic findings. RESULTS: The accuracy of US in differentiating a 50% or more severe ICA stenosis was 93% and the correlation coefficient between angiographic and US stenosis was 0.94. Peak systolic velocity of the internal carotid artery (vpICA) and its ratio to the systolic (vpICA/vpCCA) and diastolic velocity of the common carotid artery were most accurate at 70% stenosis. The vpICA/vpCCA ratio was even slightly more accurate in cases of less severe stenosis. B-mode real-time measurement of diameter stenosis was most accurate at the < 30% level. There was large variation in the flow values of the ICA, mostly due to the variability of flow in the common carotid artery. The vpCCA was low in wide and higher in medium-sized or narrow common carotid arteries. Contralateral ICA stenosis also affected the flow and thus on the vpICA/vpCCA ratio and the differentiation between significant and non-significant stenosis. CONCLUSIONS: At duplex US, B-mode real-time measurement is suitable for screening small carotid plaques and flow indices, especially vpICA and vpICA/vpCCA in severe stenoses.

[The monitoring of gas bubbles with a pulsed Doppler ultrasonic locator in humans working in a space suit]. / Monitoring gazovykh puzyr'kov ul'trazvukovym impul'sno-dopplerovskim lokatorom u cheloveka pri rabote v skafandre.

Presented are results of gas bubbles monitoring in decompressed humans with the use of an ultrasonic pulse-Doppler locator (PDL). Unlike the classic Doppler bubbles detectors with continuous US emission, PDL is adjusted for reception of echo from a chosen volume of the right ventricle cavity; thus, the clutter due to cardiac beats and human locomotion is successfully rejected. During simulation of Russian EVAs, venous gas bubbles were detected in 3 out of 5 experiments with test-subjects clothed in everyday wear and in 2 out of 3 experiments with suited test-subjects.

The analysis of the artifacts due to the simultaneous use of two ultrasound probes with different/similar operating frequencies.

The ultrasound imaging has the potential to become a dominant technique for noninvasive therapies and least invasive surgeries. Few cases may require using multiple probes of different units with different modes of ultrasound on the same patient. It generates imaging artifacts, which makes it complicated to gather information from the acquired image. This study was to identify and analyse the artifacts which are produced by simultaneous use of two probes with different/same operating frequencies. Six imaging studies were performed. First of all, the imaging artifacts of the 3.5 MHz and 6 MHz center frequencies with similar (longitudinal) positions of the probes. Secondly, with similar operating frequencies the 6 MHz probe changed from longitudinal to transverse placement to analyse the resulting artifacts. The third study was done with transverse placement of 3.5 MHz probe. The rest of the three cases were just the repetition with common pulse frequencies. Such artifacts in 3D ultrasound images are more obscure than the other artifacts associated and reported.

Womersley number-based estimation of flow rate with Doppler ultrasound: sensitivity analysis and first clinical application.

In this paper we continue in investigating the approach we have proposed in a paper recently published, for a reliable estimate of (peak systolic) blood flow rate from velocity Doppler measurements. Basic features of this approach together with some in silico test cases were discussed in that work. Here, we provide more insights of this approach by performing a sensitivity analysis of the formulas relating blood flow rate to velocity. In particular we analyze how our estimates are affected by perturbation or errors in measurements in comparison with a standard method for catheter based estimates based on the assumption of a parabolic velocity profile. A first glance to in vivo clinical applications is given as well.

A feasibility study for measuring accurate tendon displacements using an audio-based Fourier analysis of pulsed-wave Doppler ultrasound signals.

The accuracy of Pulsed-Wave Doppler Ultrasound displacement measurements of a slow moving "tendon-like" string was investigated in this study. This was accomplished by estimating string displacements using an audio-based Fourier analysis of a Pulsed-Wave Doppler signal from a commercial ultrasound scanner. Our feasibility study showed that the proposed technique is much more accurate at estimating the actual string displacement in comparison to the scanner's onboard software. Furthermore, this study also shows that a real-time Doppler data acquisition from an ultrasound scanner is possible for the ultimate purpose of real-time biological tendon displacement monitoring.

Use and limitations of immediate postprocedural intracoronary Doppler blood flow measurements for predicting late result after coronary balloon angioplasty. Results of a pilot study.

BACKGROUND AND AIMS: Physiologic measurement of myocardial perfusion in the immediate postangioplasty period may complement the angiographic assessment of the outcome of the procedure and improve our ability to identify patients at increased risk for a suboptimal late result. Immediate in-lab identification of patients at risk for late coronary restenosis would allow the interventionalist to implement alternate interventional and/or pharmacologic strategies aimed at improving the long-term outcome of angioplasty. The present single-center pilot study was undertaken to examine prospectively the value of intracoronary Doppler flow measurements immediately postangioplasty for predicting long-term patency of the dilated coronary artery. PATIENTS AND METHODS: Coronary average peak flow velocity (APV) at rest and during hyperemia (6-18 micrograms intracoronary adenosine) and coronary flow reserve in the distal coronary segment were measured in 24 consecutive patients 10-15 min after successful elective coronary angioplasty. Volume flow (Q) was calculated as APV/2 coronary cross-sectional area heart rate. Coronary arterial vessels and narrowings were measured by quantitative angiography using a geometric based method and automated edge detection. The present study reports the findings in the 16 patients undergoing conventional balloon angioplasty for whom hard endpoint angiographic data were available 4.9 +/- 1.5 months after angioplasty. RESULTS: A linear relation was present between angiographically measured minimal luminal dimension immediately postangioplasty and the late angiographic result of the procedure (r = 0.71, p = 0.0005). A greater acute gain during angioplasty was predictive of a larger luminal dimension at late angiographic follow-up (p = 0.006). There was no relation between the immediate postangioplasty Doppler flow measurements and the late angiographic result of the procedure. Late luminal dimension was not related to immediate postangioplasty basal or hyperemia APV, nor to immediate postangioplasty basal or hyperemic volume flow or to coronary flow reserve (all NS). CONCLUSIONS: In this single-center study, intracoronary blood flow and Doppler-derived coronary flow reserve immediately postpercutaneous transluminal coronary angioplasty were not predictive of long-term vessel patency or late coronary restenosis. The immediate angiographic result of angioplasty did correlate with the late result of the procedure.

Color Doppler energy prediction of malignancy in adnexal masses using logistic regression models.

OBJECTIVE: The aim of this study was to assess the usefulness of color Doppler energy in the preoperative diagnosis of ovarian malignancy using multivariate logistic regression analysis. METHODS: One hundred and thirty adnexal masses were studied with transvaginal B-mode, color energy, and pulsed Doppler ultrasonography before surgery in order to develop a model that could be used to determine malignancy. Each ultrasonographic variable (tumor size, wall thickness, septal structure, echogenicity, papillary projection, density (solid or not)) was included individually or combined together as part of the Sassone ultrasound score. Intratumoral blood flow velocity waveforms were obtained to determine pulsatility index and resistance index and a more subjective parameter, location of tumor vascularity, was also assessed. Menopausal status and serum CA 125 levels were also entered as categorical variables. Sonographic parameters were entered alone, then associated with menopausal status and CA 125 serum levels, and finally with Doppler energy measurements. Our model was then validated in a group of 68 adnexal masses and compared to the model of Alcazar. RESULTS: Eighteen adnexal masses (13.8%) were malignant or of low malignant potential. Multivariate analysis showed that papillary projection of the tumor wall, cyst with solid parts, resistance index with a cut-off value of 0.53, CA 125, and central blood flow location, were the only factors to be independent predictors of malignancy. Menopausal status was not an independent factor. For the final model including the Doppler energy parameter the best sensitivity and specificity were 83% and 93%, respectively, at a cut-off value of 10% probability of malignancy compared to 83% and 87% for the morphological variables alone. Validation of the model showed its diagnostic performance to be as good as that reported in the original population and better than the model of Alcazar. CONCLUSION: Sonographic analysis of adnexal masses including color Doppler energy shows the best predictive properties according to histological diagnosis, and improves preoperative diagnosis of malignancy.

Hepatic involvement in Osler-Weber-Rendu disease: findings on pulsed and color Doppler sonography.

OBJECTIVE: The purpose of this study was to compare the hemodynamics of the liver vasculature as determined by Doppler sonography for patients with Osler-Weber-Rendu disease and for healthy subjects. SUBJECTS AND METHODS: Real-time color Doppler sonography and pulsed Doppler sonography were used to study 10 patients with Osler-Weber-Rendu disease and 25 healthy subjects. Vessel diameter and flow velocity in the hepatic artery and its branches as well as in the portal vein and its segmental branches were determined. Flow patterns in the hepatic veins were analyzed. The clinical manifestations of the disease were correlated with the Doppler sonographic findings. RESULTS: The hepatic artery and its branches were dilated and tortuous, and flow velocity was greater in patients than in healthy subjects; hepatic artery velocities (mean +/- SD) were 153 +/- 65.2 cm/sec versus 64.9 +/- 11.4 cm/sec (p < .005). The resistive index measured in the hepatic artery did not differ significantly between the two groups (p was not significant). No intrahepatic arteriovenous shunt sites were detected by color Doppler sonography. However, arterioportal shunts were observed in two patients, one of whom also had a portovenous shunt. A portovenous shunt and multiple shunts between hepatic veins were found in another patient. Portal venous flow was similar in both groups. No relationship between Doppler sonographic changes and clinical manifestations was found. CONCLUSION: The multiple microscopic arteriovenous shunts found in Osler-Weber-Rendu disease were not detected in our patients but resulted in dilatation and increased flow velocity in the hepatic artery. Flow velocity in the portal vein appeared to be undisturbed. Large intrahepatic shunts were easily outlined by Doppler sonography.

[Cardiovascular risk factors and carotid atherosclerosis detected by ultrasonography]. / Factores de riesgo cardiovascular y aterosclerosis carotídea detectada por ultrasonografía.

OBJECTIVES: To assess the frequency of carotid atherosclerosis and its relation to cardiovascular risk factors in a general elderly population of Mexico City. MATERIAL AND METHODS: B-mode ultrasonography was performed to investigate carotid atherosclerosis in 145 CUPA (a research project) participants, between July 1993 and January 1996. The outcome was then related to cardiovascular risk factors. RESULTS: Prevalence of ultrasound-detected carotid atherosclerosis was 64.8%. Intimal-medial thickening was detected in 64 subjects (44.1%) and carotid plaques in 82 (56.5%); Fifty-two subjects had both intimal-medial thickening and plaques. However, only 8 subjects had carotid plaques with severe stenosis (5.5%). There were no significant differences in the prevalence of atherosclerotic lesions (male 61.9%, female 66.0%). Carotid atherosclerosis was significantly associated with age (p < 0.0001), high blood pressure (p < 0.001), isolated systolic hypertension (p = 0.01), hypercholesterolemia (p = 0.04), and diabetes mellitus (p = 0.06). Prevalence of carotid atherosclerosis increased progressively with the number of vascular risk factors. CONCLUSIONS: There was a high prevalence of carotid atherosclerosis in this general elderly population of Mexico City, and was almost equal to that reported in developed western countries. Age, hypertension, hypercholesterolemia, and diabetes were the strongest predictors of atherosclerosis.

[The evaluation of atherosclerotic lesions of the extracranial carotid arteries in hypertensive subjects. A study by B-mode and pulsed Doppler echotomography]. / Valutazione delle lesioni aterosclerotiche delle arterie del tratto carotideo extracranico in soggetti ipertesi. Studio mediante ecotomografia B-mode e Doppler ad onda pulsata.

Arterial hypertension is considered an independent atherosclerotic risk factor. In hypertensive patients it increases cardiovascular morbidity and mortality risk. The aim of the study was to emphasize the presence of atherosclerotic lesions at the level of extracranial carotid tree in patients with essential arterial hypertension. In 110 hypertensive patients (63 males, 47 females) mean age 66 +/- 16 years, and in 100 normotensive patients (66 males, 34 females) mean age 65 +/- 15 years, high-resolution B-mode pulsed wave Doppler echotomography of internal, external and common carotid artery of both sides was performed. The value of the intimal-medial complex thickness of common carotid was measured, and the stenosis percentage evaluated by B-mode pulsed wave Doppler echotomography. Atherosclerotic plaques were classified according to their echogenic characteristic and surface; their localization was then evaluated. In hypertensive patients we observed the presence of common carotid intimal-medial thickening in 75.4%, atherosclerotic plaques in 60.9% and stenosis in 17.9%; 58.3% of these ones were localized at internal carotid, 33.3% at common carotid and 8.3% at external carotid. We observed that 36% of the 100 normotensive patients presented common carotid intimal-medial thickening (p < 0.001 versus hypertensives), 25% atherosclerotic plaques (p < 0.001 versus hypertensives) and 8% stenoses; 50% of these stenosis were localized at internal carotid, the second half at external carotid. In conclusion, high-resolution B-mode echotomography study with pulsed wave Doppler spectral analysis represents a necessary method to evaluate the condition of the extracranial carotid tree in patients with hypertension.

Estudo comparativo eentre os índices dopplervelocimétrico obtidos em diferentes locais de insonaçäo do cordäo umbilical / Comparative study between the dopplervelocimetric index obtaines in different sites of insomnation of umbilical cord

Os autores fizeram um estudo prospectivo onde analisaram e compararam o índice de resistência da artéria umbilical obtido em pontos extremos do cordÝo. A análise estatística mostrou significância importante, ou seja, o índice de resistência da artéria umbilical junto a placenta sempre se mostrou mais baixo quando comparada à regiÝo junto ao abdome fetal. Os autores terminam o trabalho alertando que o local de insonaçÝo da artéria umbilical é um fator técnico importante, e portanto deve ser padronizado pelos ultra-sonografistas

Mola parcial: diagnóstico por angiografía ultrasónica y Doppler pulsado, seguimiento y resultado perinatal / Parcial mole: diagnostic by ultrasonic angiography and pulsate Doppler, following and perinatal result

Se presenta un caso de Mola Parcial cuyo diagnóstico definitivo se realizó mediante angiografía ultrasónica. La uteroinhibición con Progesterona micronizada permitió llegar a las 30 semanas con parto espontáneo y un exitoso resultado perinatal

Mola parcial: diagnóstico por angiografía ultrasónica y Doppler pulsado, seguimiento y resultado perinatal / Parcial mole: diagnostic by ultrasonic angiography and pulsate Doppler, following and perinatal result

Se presenta un caso de Mola Parcial cuyo diagnóstico definitivo se realizó mediante angiografía ultrasónica. La uteroinhibición con Progesterona micronizada permitió llegar a las 30 semanas con parto espontáneo y un exitoso resultado perinatal (AU)