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At least 307 records · Page 17Linked to original sources

PubMed2002

Coronary Doppler measurements do not predict progression of cardiac allograft vasculopathy: analysis by serial intracoronary Doppler, dobutamine stress echocardiography, and intracoronary ultrasound.

Coronary flow velocity reserve (CFVR) (maximum/baseline flow velocity, 16 microg adenosine) was compared with dobutamine stress echocardiography (DSE) (5 to 40 microg/kg/min) to assess the progression of angiographically silent cardiac allograft vasculopathy (CAV). As a reference for the morphologic assessment of CAV, serial intracoronary ultrasound (ICUS) measurements were performed. An increase in CFVR could be observed in all transplant patients despite morphologic or functional progression of CAV or non-progressive CAV as assessed by ICUS or DSE. Thus, serial intracoronary Doppler flow analysis is not useful to predict morphologic or functional progression of CAV.

Adult↗

PubMed2004

Transcutaneous colour Doppler sonography of lung consolidations: review and pictorial essay. Part 2: colour Doppler sonographic patterns of pulmonary consolidations.

The first ultrasound examinations of the lung were performed 30 years ago. In contrast to abdominal ultrasound, lung examination by ultrasound is not established as a routine method, due to a nearly complete sound reflection by the bones of the thorax and the aerated lung. In the last years B-mode sonographic patterns of peripherally based pleural lesions have been described. Colour Doppler sonography (CDS) further extends the diagnostic potential of ultrasound in chest disease. This article will review qualitative and quantitative CDS patterns of different pulmonary lesions.

Humans↗

PubMed1996

[Doppler ultrasound in cases of Rhesus incompatibility. Effect of intravascular punctures with or without transfusion on feto-placental Doppler blood flow velocity curves].

OBJECTIVE: To investigate the influence of cordocentesis with or without blood transfusion on umbilical and fetal blood flow characteristics. METHODS: Of 42 pregnant women suffering from Rh. incompatibility 15 had a puncture of the umbilical cord for diagnostic reasons only. In 27 cases a total of 86 punctures was done for blood transfusion. Fetal heart rate, umbilical artery A/B Ratio and Pulsatility Index (PI) in the fetal aorta were measured before and after cordocentesis in all cases having or having not a transfusion. RESULTS: Diagnostic and therapeutic cordocentesis resulted in a slight decrease of peripheral resistance. Significant differences were only observed in cases with a haematocrit < 20% compared to cases with values > 40% or if the final haematocrit after transfusion resulted in a value of < 30%. CONCLUSION: The decrease peripheral resistance in cases of therapeutic cordocentesis can be attributed to the increase in blood volume and sufficient oxygenation of blood improving fetal perfusion. Doppler sonography is not helpful in the clinical management of red blood cell immunisation.

Adult↗

PubMed2001

Age-dependent changes in regional diastolic function evaluated by color Doppler myocardial imaging: a comparison with pulsed Doppler indexes of global function.

The goals of this study were to evaluate possible normal age-related changes in regional myocardial relaxation as detected by color Doppler myocardial imaging (CDMI) velocities and to compare the extent of any such changes with age-induced changes in global diastolic function. In 80 healthy subjects (aged 21 to 72 years, equally subdivided by decades) the mitral flow velocities in early diastole (E) and atrial contraction (A) were recorded as were the velocities of left ventricular (LV) motion of early (EDV) and late diastole (LDV) in the 16 standard LV segments, and their ratios were calculated. In healthy persons younger than 40 years, all segments showed an EDV/LDV ratio > 1, whereas in healthy persons aged 40 years or older the mean EDV of all segments decreased, and the mean LDV increased, resulting in a significant decrease of the mean EDV/LDV ratio with age. Values of EDV/LDV ratios were higher than E/A ratios (P <.0001), but their changes with age correlated well with each other (r = 0.805). With increasing age, an EDV/LDV ratio <1 was observed more often in basal segments (P <.001, compared with mid and apical segments) and less often in segments of anteroseptal and posterior walls viewed from the parasternal window. The presence of >50% segments with an EDV/LDV ratio <1 was associated with an E/A ratio <1. Regional diastolic function indexes as evaluated by CDMI changed with increasing age in a heterogeneous way and influenced global diastolic function parameters.

Adult↗

PubMed1993

Doppler haemodynamic assessment of clinically and echocardiographically normal mitral and aortic Allcarbon valve prostheses. Valve Prostheses Ligurian Cooperative Doppler Study.

Doppler echocardiographic characteristics of normally functioning Allcarbon prostheses were studied in 149 consecutive patients with 157 valves in the mitral (n = 73) and aortic (n = 84) positions whose function was considered normal by clinical and echocardiographic evaluation. In the mitral position, the mean gradient and the effective mitral orifice area were not significantly different in either the 25-mm or the 31-mm size valves (from 5 +/- 1 to 4 +/- 1 mmHg and from 2.2 +/- 0.6 to 2.8 +/- 0.9 cm2, respectively; P = ns for both). Conversely, peak gradient was significantly and inversely correlated to actual orifice area (r = -0.70; P < 0.0006), decreasing from 15 +/- 3 mmHg in the 25-mm size valve to 9 +/- 1 mmHg in the 31-mm size. In the aortic position, the mean gradient was 29 +/- 8 mmHg in the 19-mm size valve; it decreased to 8 +/- 2 mmHg in the 29-mm size. Effective prosthetic aortic valve area, calculated using the continuity equation, ranged between 0.9 +/- 0.1 cm2 for the 19-mm size valve to 4.1 +/- 0.7 cm2 for the 29-mm size. By analysis of variance, effective prosthetic aortic valve area differentiated various valve sizes (F = 25.3; P < 0.0001) better than peak (F = 5.34; P = 0.012) or mean (F = 4.34; P = 0.0052) gradients alone, and it correlated better with actual orifice area (r = 0.89, r = -0.70 and r = -0.65, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

The impact of the measuring distance on laser-Doppler measurements of the microcirculation in human nasal mucosa. A study of rhinostereometry and micromanipulator-guided laser-Doppler flowmetry.

Fourteen healthy volunteers were examined using rhinostereometry (RSM) and micromanipulator-guided laser-Doppler flowmetry (LDF) on the inferior turbinate and nasal septum. There were significant differences of the flowmetry readings at different distances from the mucosal surface within 0-1.0 mm. Changes in LDF values due to a change in distance between probe and mucosa seem to be an important artefact that will influence the flowmetry, especially if the probe is fixed to the framework of the nose (i.e. the skull) and if the congestive status of the mucosa changes. This can be a problem especially during intranasal challenges with substances that influence congestion. These artefacts can be eliminated by using an RSM-guided micromanipulator that allows the probe to follow changes in congestion.

Adult↗

PubMedDate not supplied

Evaluation of cross-circulation through circle of Willis using an ultrasonic Doppler technique. Part I. Comparison between blood flow velocity by ultrasonic Doppler flowmetry and angiogram.

In 24 patients with cerebrovascular disease and 6 without organic brain lesions, the increased velocity of blood flow in both the internal carotid and vertebral arteries during a contralateral carotid compression was compared with the angiographic appearance of the circle of Willis. The flow velocity was measured using ultrasonic Doppler flowmetry. It was not possible to investigate fully the relationship between the increase of velocity of blood flow in the internal carotid artery and the anatomical variations of the circle of Willis, specifically the anterior cerebral and communicating arteries. The velocity of flow in the patients with an aplastic proximal portion of the anterior cerebral artery showed no increase. There were no differences in the increase of velocity of flow in the vertebral artery in patients with hypoplastic, normal and fetal posterior communicating arteries. It is considered that although anatomical variations of the circle vessels influence the cross-circulation via the circle of Willis, peripheral vascular factors distal to the circle also play an important role in the quantity of cross-circulation through the circle.

Adolescent↗

PubMed2006

Non-visualization of the internal carotid artery with a normal ipsilateral common carotid artery Doppler waveform: a finding suggesting congenital absence of the ICA on colour Doppler ultrasound.

We report a case of congenital absence of the left internal carotid artery (ICA) that presented with left-sided facial numbness. On MRI of the brain, occlusion of the left cavernous ICA was suggested. On colour Doppler ultrasound (CDS), the left ICA was not visualized and the ipsilateral common carotid artery (CCA) showed normal flow in systole and diastole. Combined with the correct identification of the left external carotid artery (ECA), these findings were suggestive of congenital absence of the ICA rather than occlusion. The final diagnosis of congenital absence of the ICA was confirmed with CT of the skull base.

Adult↗

PubMed1990

Usefulness of left and right oblique subcostal view in the echo-Doppler investigation of pulmonary arterial blood flow in patients with chronic obstructive pulmonary disease. The subxiphoid view in the echo-Doppler evaluation of pulmonary blood flow.

Fifty-nine adult patients with chronic obstructive pulmonary disease (COPD) underwent Doppler and two-dimensional echocardiographic examination to determine the variability of pulmonary arterial blood flow (PABF) from multiple views. Measurement of peak flow velocity (PFV), acceleration time (AT), right ventricular ejection time (RVET), and pulmonary arterial diameter (PAD) was possible in 52 patients (88 percent) by left oblique subcostal view (LOSV), in 38 patients (64.4 percent) by right oblique subcostal view (ROSV), and in only 12 patients (20.3 percent) by short axis parasternal view (SAPV) (p less than 0.05). Overall, PABF was measured in 55 patients (93.2 percent). The LOSV gave consistently higher values of PVF than those obtained either by ROSV (p less than 0.05) or by SAPV (p less than 0.05). We conclude that LOSV and ROSV allow measurement of PABF in the majority of patients with COPD.

Aged↗

PubMedDate not supplied

[Idiopathic varicocele. Diagnosis and follow-up with CW-Doppler and Echo-Color-Doppler: our experience].

The Authors outline their experience on routine use of Doppler velocimetry in pre- and post-operation studies on patients affected with idiopathic varicocele. This instrumental study, characterized by non-invasive techniques and repeatability, if correctly carried out, allows both accurate identification of anatomical alterations which are at the bottom of varicocele and correct indications for surgical treatment. Moreover the Authors confirm the importance of spermatic veins ligature following the Ivanissevich method in the treatment of male infertility.

Adult↗

PubMed2003

[Rationale of Doppler urodynamics and urodynamics. What does Doppler contribute to urodynamics?].

OBJECTIVES: To make an analysis of the usefulness of urodynamic tests and what can be obtained from them. METHODS: We also perform and analytical deduction of those parameters that define detrusor behavior, such as the constant defining bladder compliance, the bladder elastic constant, in its tensile properties, and we found the expression of resistances and calculate the abdominal pressure formula; therefore we don't need to introduce a rectal catheter to know the value of those parameters that define bladder dynamics. RESULTS: Although they are provisional, they allow foreseeing a promising future for this application of a well-known device. CONCLUSIONS: Currently, we can only define the bladder behaviour, its resistances, the detrusor drive and compliance with the only discomfort of a perineal Doppler ultrasound. Time will open new possibilities.

Humans↗

PubMed1992

[Doppler-metric and Doppler echocardiographic study of the nature and stage of disorders of fetal hemodynamics in intrauterine fetal growth retardation].

Pregnancy course, labor outcome, and doppler-metric findings were analyzed in 174 women, 98 with normal pregnancy (controls) and 76 with small-for-date fetuses when examined on weeks 28-41; the aim of the study was to analyze the pattern of hemodynamic disorders in small-for-date fetuses. A classification of fetal hemodynamic disorders has been developed, that distinguishes three types of disorders differing in severity: first degree--disordered fetoplacental circulation not reaching the critical values and satisfactory fetal hemodynamics; second degree--compensated disorders of fetal hemodynamics; third degree--critical state of fetal hemodynamics. Use of this classification in clinical practice will help define rational strategy of pregnancy follow-up.

Echocardiography, Doppler↗

PubMed1994

[The value of CW Doppler and Doppler-color-echocardiography in the mass screening for atherosclerotic carotid lesions].

BACKGROUND: The availability of non invasive ultrasound technologies for the diagnosis of extracranial carotid atherosclerotic disease allowed designing and applying mass screening programmes devoted to uncover and study unknown carotid stenosis in resident populations. OBJECTIVE: To evaluate usefulness and correct application of Continuous Wave Doppler (CWD) and Color Coded Echo Flow Imaging (CCEF) examinations during different levels of the screening programme OPI (Obiettivo Prevenzione Ictus). METHODS: Between January 29th 1990 and March 31st 1992 the screening programme OPI has been applied to 16.379 subjects of both sexes, aged 45 to 75, enrolled in a sanitary district of Lombardia. They underwent first level screening (anamnesis, physical examination, CWD of carotid arteries). 1.661 (10.1%) were suspected of harboring carotid lesions and invited to second level screening (physical examination, biohumoral sampling, CCEF): 1.587 attended. The results of CWD and CCEF examination of 3.174 carotid arteries are discussed. RESULTS: An overall sensitivity and specificity of 63.6% and 66%, respectively, was found as CWD and CCEF were compared for lesions detectable by CWD (i.e. excluding kinkings and aneurysms). Of 1.815 carotid arteries classified as negative at CWD the absence of lesions was confirmed by CCEF for 1.450 (79.9%); CWD failed to reveal 146 (8%) stenosis < 50% and 52 (2.9%) severe lesions, of which only 5 (0.3%) could possibly undergo surgical treatment. CONCLUSIONS: Despite low accuracy, CWD has proven to be useful for the purpose of a mass screening of carotid occlusive disease, that is selection of a contained group of subjects (10.1%), with increased risk for carotid stenosis, for further non invasive examination, with low cost (hardware cost: 1.430 lire per exam v/s 24.000 lire per exam for CCEF) and low risk of missing severe stenosis with possible surgical indication (0.3%).

Aged↗

PubMedDate not supplied

Diagnosis of acute intestinal ischemia by color Doppler sonography. Color Doppler sonography and acute intestinal ischemia.

Detection of acute intestinal ischemia is a diagnostic challenge. Color Doppler sonography of the abdomen may contribute to its diagnosis by showing lesions of the gut wall associated with occlusion or stenosis of the mesenteric vessels. Our overview of the sonographic findings of acute intestinal ischemia is presented as well as a proposition of algorithm for the working up to the diagnosis based on recent clinical experience.

Arterial Occlusive Diseases↗

PubMed1992

Evaluation by colour Doppler and pulsed Doppler sonography of blood flow velocities in intracranial arteries during the early neonatal period.

Using a colour pulsed Doppler flow mapping system, we examined the intracranial arteries of 40 healthy infants. The anterior cerebral, basilar, intracranial internal carotid and middle cerebral arteries were visualized clearly enough to evaluate flow velocity at the success rates of 100%, 87.5%, 65% and 82.4%, respectively. In the anterior cerebral, intracranial internal carotid and middle cerebral arteries, the maximum blood flow velocity slightly decreased to a minimum at around 4-6 h after birth, and then gradually increased. The minimum blood flow velocity pattern was similar. The maximum blood flow velocity in the basilar artery decreased from 0-3 h, rapidly increased from 4-6 h, and remained at a steady level thereafter. A possible mechanism for the chronological changes in the intracranial blood flow velocity is discussed.

Blood Flow Velocity↗

PubMed1991

An investigation of simulated umbilical artery Doppler waveforms. II. A comparison of three Doppler waveform quality indices.

Three Doppler waveform quality indices based upon assessment of the noise of the maximum frequency envelope of simulated umbilical artery waveforms were investigated. These indices were: an estimate of the correlation between successive waveforms (QI1), a local linearity measure (QI2) and a ratio of two regions of the Fourier transform amplitude spectrum of the maximum frequency envelope (QI3). Simulated umbilical artery waveforms were acquired from a physiological flow phantom. A test population was used consisting of a large number of waveforms where one of three physical variables had been adjusted to produce waveforms of varying quality. These three physical variables were: beam-vessel angle, beam-vessel axial misalignment and attenuator thickness. For this group of waveforms the accuracy of estimation of the maximum frequency envelope and pulsatility index (PI) were known. All three quality indices gave good separation of high- and low-quality waveforms based upon threshold values of the accuracy of PI and maximum frequency envelope. The dependence of each quality index on fetal breathing, waveform length and waveform pulsatility was investigated. QI2, the local linearity measure, showed most promise in its independence from these variables.

Humans↗

PubMed1977

[Pre- and postoperative Doppler-ultrasound measurements in carotid artery surgery (carotid artery Doppler) (author's transl)].

The evaluation of carotid artery perfusion with Doppler-ultrasound is based on semiquantitative measurements of blood flow in the terminal branches of the ophthalmic arteries (supratrochlear and supraorbital artery) and the common carotid arteries. Diagnosis is performed with a set of 8 parameters and informs about obstructions in the carotid artery as well as the collateral circulation. The method was applied on 1500 patients of whom 340 underwent angiography and has proved to be about 90% reliable. Its value in carotid artery surgery was evaluated with 62 extracranial reconstructive operations on 55 patients and 35 iatrogene anastomoses between the temporal superficial and a branch of the middle cerebral artery on 35 patients.

Arterial Occlusive Diseases↗

PubMed1988

Validity of laser Doppler flowmetry for measuring the effect of the tissue expander pressure on skin circulation. Simultaneous measurement of tissue pressure and laser Doppler flowmetry.

Intermittent Laser Doppler Flowmetry (LDF) was used in five patients to measure changes in the dermal blood flow when changing intraluminal pressures in tissue expanders (TE). In another patient, continuous monitoring of the intraluminal pressure in the TE and simultaneous LDF was used. Our finding is that LDF is a suitable method for the registration of reactions in dermal circulation, caused by TE pressure changes. A statistically significant association between the changes of the LDF values and the intraluminal pressure in the TE was observed.

Adolescent↗