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At least 19 recordsLinked to original sources

PubMedDate not supplied

[Ultrasound Doppler sonography in obstetrics. A comparison between simple Doppler methods (continuous or pulsed Doppler) and the duplex system (combination of B-image and pulse Doppler)].

120 pregnant women between the 26th and 42nd week of gestation have been examined using simple Doppler-units with pulsed- or continuous-wave technique and duplex Doppler-units (combined B-mode and pulsed-wave Doppler). The umbilical and uterine arteries were measured with both units in a semi-recumbent position at the same time by the same examiner. Only ideal flow profiles were taken to calculate the S/D-ratio. Our results were correlated to the fetal outcome, to all cases of pre-eclampsia and to all cases of intra-uterine growth retardation. Except in one of these cases we got the majority of pathological results using simple Doppler-units. Only in pre-eclampsia the duplex Doppler-units had the majority of pathological results. Even in normal fetal outcome the majority of simple Doppler-unit results are pathological. This finding is due to the impossibility to localize the vessel exactly using simple Doppler-units. Sensitivity is higher in simple Doppler-techniques (74.3% to 52.9%), specificity is higher in duplex Doppler-technique (77.9% to 52.6%).

Female↗

PubMed1992

[Doppler ultrasound study of breast tumors using color Doppler ultrasound, duplex ultrasound and the CW Doppler ultrasound].

The preoperative examinations by doppler-sonography of 83 patients with tumors of the breast are presented. The examinations are done with newest technique: duplex-sonography in slow-flow-technique (AI 3200, Dornier); colour-sonography in MEM-technique (AI 5200, Dornier) and synchronical colour-doppler++ (Quantum 2000, Siemens) and CW-doppler-sonography (Vasocope 3, Kranzbühler). There is a markable difference between the side of carcinoma and the normal side as well as pre- and postmenopausal patients. No difference is shown in cases of benign tumors and the normal side. The increasing blood flow of a malignant tumor is showed in changing the doppler parameters (A/B-ratio and resistance-index) and in the doppler wave form. The number of vessels found in or around a tumor is not a good criteria to find malignant diseases, the best criteria is the difference between sides of the mamma.

Blood Flow Velocity↗

PubMed1990

Carotid artery disease assessed by color Doppler flow imaging: correlation with standard Doppler sonography and angiography.

Carotid artery disease was assessed in 180 patients by means of color Doppler flow imaging. Color Doppler findings in 360 carotid arteries were compared with the results of standard Doppler sonography, and color Doppler findings in 60 bifurcations were compared with the results of intraarterial angiography. The sensitivity of color Doppler for the detection of carotid disease was 100% when compared with angiography. The accuracy of color Doppler in classifying minor (40-60%), moderate (61-80%), and severe (81-90%) stenosis ranged from 91.3% to 97.8% vs standard Doppler sonography, and from 91.7% to 95.8% vs angiography. Whereas all occlusions were identified correctly by both color Doppler and angiography, four pseudoocclusions of the carotid artery were misdiagnosed as occluded. Characteristic features providing reliable criteria of the degree of stenosis are (1) intensity, extent, and duration of color fading; (2) postprocessed systolic peak frequency; (3) plaque extent on serial sonograms; and (4) poststenotic flow patterns. Display of hemodynamic disturbances induced by less pronounced plaques showed highly variable patterns that could not be anticipated from the plaque morphology alone. Thus, color Doppler preserves the advantages of standard Doppler and duplex sonography but provides additional information about otherwise anechoic necrotic and thrombotic material that often causes cerebral embolisms. With atherogenesis, repair mechanisms may be sustained or progression be stopped by reducing the risk factors and instituting medical treatment; thus, the application of this noninvasive technique is important.

Adult↗

PubMedDate not supplied

Carotid artery disease assessed by color Doppler flow imaging: correlation with standard Doppler sonography and angiography.

Carotid Artery Diseases↗

PubMed1989

[A comparative study of pulsed Doppler versus continuous Doppler technic without spectral analysis in obstetrics].

We conducted a study in 48 parturients in order to: --assess the possibilities of continuous Doppler examination without preliminary ultrasonographic localization and without spectral analysis, to measure the traditional hemodynamic parameters of fetal development (in particular on the umbilical cord). --to compare these results with those obtained using pulsed Doppler-scan as reference. The protocol was very strict and neither of the two practitioners was aware of the other practitioner's results. With the continuous Doppler examination, the uterine arteries were systematically localized and recorded. The technique is simple in trained hands. The material included an ultrasonograph fitted with two probes (3.5 and 5 MHz, equipped with a pulsed Doppler) and a continuous Doppler (only the 4 MHz probe was used). Because the tests were sometimes repeated, 63 measurements were obtained in 48 parturients, mean age was 29.3 years and mean gestational age was 32.9 weeks. The reason for the examination varied: intrauterine growth retardation and/or maternal hypertension, diabetes, etc. The results obtained from the cord proved to be very encouraging: 42 of the 54 measurements were comparable (77.7%) showed an index difference less than or equal to 0.05. Only 4 (7.4% of the measurements) maximum deviations were observed (exceeding 0.10). The mean Pourcelot index on the Doppler scan was 0.677. With the continuous Doppler, it was 0.676. The 13 abnormal measurements with the pulsed Doppler were also abnormal with the continuous Doppler. The uterine arteries were recorded and measured with the continuous Doppler 42 times on the right (68.8% of the cases) and 34 times on the left (55.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

[Clinical usefulness of the Doppler-echocardiographic method for evaluating intracardiac shunts. Combined Doppler and hemodynamic study].

The purpose of this study was to assess the accuracy of a quantitative two-dimensional Doppler echocardiographic method for estimating systemic and pulmonary blood flows in atrial and ventricular septal defects. Twenty-eight patients (mean age 22 +/- 14), with atrial septal defect (ADS) or ventricular septal defect (VSD) underwent Doppler-echocardiography and cardiac catheterization in order to assess pulmonary blood flow (QP), systemic blood flow (QS), the left to right shunt (SH) and the ratio of pulmonary to systemic flow (QP/QS ratio). Cardiac output was also determined by the oximetry method according to Fick principle. Pulmonary output assessed by Doppler was 7.9 +/- 0.61/min, by catheterization 9.0 +/- 3.9. Linear regression analysis showed a low correlation coefficient (r = 0.10; p = NS). Systemic output evaluated by Doppler resulted 4.6 +/- 1.4 l/m, while at catheterization 5.1 +/- 1.5 l/min (r = 0.25; p = NS). Doppler evaluation of left-to right shunt was 3.3 +/- 1.5 l/min, at catheterization 3.9 +/- 3.1 (r = 0.74; p less than 0.001). Doppler QP/QS ratio resulted 1.7 +/- 0.5, at catheterization 1.8 +/- 0.5 (r = 0.96; p less than 0.0010. The results showed that, in spite of the lack of correlation between the pulmonary and systemic outputs assessed by Doppler vs catheterization, QP/QS ratio, as well as SH, are useful noninvasive indexes in order to evaluate intracardiac shunts.

Adolescent↗

PubMed1991

Laser Doppler flowmetry, transcutaneous oxygen tension measurements and Doppler pressure compared in patients undergoing amputation.

The level of amputation continues to present a challenge for surgeons. In view of this, 24 patients who required an amputation of their ischaemic leg were studied prospectively using Laser Doppler flowmetry (LDF), TcpO2 measurements and Doppler ultrasound to assess the best level for amputation. In all patients gangrene of the leg and rest pain were the indication for an amputation. Skin oxygen tension (TcpO2) and skin blood flow (LDF) measurements were obtained the day before surgery on the proposed anterior and posterior skin flaps for below knee amputation and the maximum Doppler systolic pressure was measured. The level of amputation was chosen at surgery by clinical judgement without reference to the measurements mentioned above. A below knee amputation was performed in 17 patients and an above knee in seven. All amputations healed by primary intention. Doppler pressures showed poor discrimination with a median value of 10 mmHg (0-25) in AK patients and 35 mmHg (0-85) in the BK group (p greater than 0.05). In contrast TcpO2 showed a trend. In the BK group the median value was 20 mmHg (4-50) on the anterior and 22 mmHg (2-60) on the posterior flap compared to above knee amputees with median values of 6 mmHg (2-11) and 8 mmHg (3-38), respectively (p greater than 0.05). Laser Doppler seemed more useful. In BK patients the median LDF values were 36 mV (20-85) on the anterior and 34 mV (20-80) on the posterior flap with median LDF values of 10 mV (10-18) on the anterior and 11 mV (8-38) on the posterior flap in the above knee group (p less than 0.01). Laser Doppler flowmetry is a simple objective test, which is a better discriminator of skin flap perfusion than either TcpO2 or Doppler ankle pressures.

Aged↗

PubMed1992

[Catheter-induced femoral artery lesions: diagnosis with B-mode ultrasound, Doppler ultrasound and color Doppler ultrasound].

A total of 44 patients were evaluated to compare the value of B-mode sonography, Doppler sonography and colour coded Doppler sonography. All patients were studied because of suspected lesions of the femoral arteries following diagnostic and/or therapeutic cardiac catheterisation. B-mode sonography was unable to reliably differentiate between haematoma and pseudo-aneurysms, a.v.-fistula or combined lesions. Colour coded Doppler sonography can better demonstrate haematoma and thrombi in pseudo-aneurysms. The neck of a pseudoaneurysm can be exactly depicted by colour coded Doppler sonography. A.v.-fistula is shown by colour coded Doppler sonography based on typical colour coding and the Doppler spectrum. Combined lesions of pseudo-aneurysm and a.v.-fistula cannot reliably be detected by colour coded Doppler sonography, duplex sonography and B-mode sonography.

Adult↗

PubMed1992

[Vascular pathology of urologic significance: Doppler and color Doppler].

The combined use of B-mode ultrasonography and doppler (p.w. and/or color doppler) provides a more accurate and detailed study of vascular pathology than B-mode ultrasonography alone. In fact, besides to document the presence of blood flow and to assess its direction, doppler US provides a quantitative evaluation of blood flow. Chromatic codification of blood flow (usually red if flowing towards the probe, blue if flowing away from the probe and yellow or green in the case of turbulence) permits to assess the presence of blood flow even in areas where a vessel cannot be depicted by B-mode ultrasonography. In fact in the study of blood flow to the kidney it's possible with color-doppler to visualize not only the main renal arteries but segmental-intraparenchymal arteries too; that is very useful in the detection of rejection of allograft. In renal artery, blood flow presents a pattern of low resistance: a brief systolic phase followed by a longer diastolic one, without inversion of flow. In renal vein, blood flow is, on the contrary, continuous. The main disorders of the kidney and urinary tract, which can be detected by color doppler are the following: renal-vascular hypertension, rejection of allograft, renal vein thrombosis, portal hypertension with spleno-renal collateral channels, disorders of ureteral motility, space occupying lesions, medical nephropathies and obstructive uropathies. Sophisticated analysis of the flow pattern to the kidney with color doppler, by some doppler sonographic parameters (resistance index RI, pulsatility index PI), in these disorders adds a functional element to the traditional ultrasonographic imaging with a better characterization of the disease.

Graft Rejection↗

PubMed1991

Experimental study of the effects of pulsed Doppler sample volume size and position on the Doppler spectrum.

With a pulsed Doppler system, the recorded Doppler spectrum is expected to vary depending upon the sample volume size relative to the diameter of the vessel, the position of the sample volume in the vessel and the velocity profile. In the in vitro experiments described in this paper, the velocity profile was kept constant by using steady parabolic flow in a flow model. As the Doppler sample volume size and position were changed, the maximum variations of quantitative measurements from the Doppler spectrum were determined. The maximum, mean and mode frequencies and spectral broadening index (SBI) were affected by the position of the sample volume but to a lesser degree by its length (1.5-5.0 mm) relative to the 9.5 mm beam path length across the tube. When the centre of the Doppler sample volume was moved within the central 25% of the tube, the maximum variations were as follows: maximum frequency 3-5%, mean frequency 8-9%, mode frequency 8-9% and SBI 16-18%, where the range indicates the effect of increasing the sample volume size. Based on these results obtained under steady flow conditions in vitro, it is concluded that quantification of pulsed Doppler spectra may be feasible if the sample volume is positioned within the central 25% of the vessel.

Blood Flow Velocity↗

PubMed1990

Doppler echocardiographic measurement of pulmonary artery pressure from ductal Doppler velocities in the newborn.

The ductal flow velocities in 37 newborns (group 1: persistent pulmonary hypertension [n = 16], transient tachypnea [n = 3], other [n = 2]; group 2: respiratory distress syndrome [n = 16]) were prospectively evaluated by Doppler ultrasound for the purpose of deriving systolic pulmonary artery pressures. Maximal tricuspid regurgitant Doppler velocity in 21 of these patients was used to validate the pulmonary artery pressures derived from ductal flow velocities. There was a significant linear correlation between tricuspid regurgitant Doppler velocity and pulmonary artery systolic pressure derived from ductal Doppler velocities in patients with unidirectional (pure left to right or pure right to left) ductal shunting (p less than 0.001, r = 0.95, SEE 8) and in those with bidirectional shunting (p less than 0.001, r = 0.95, SEE 4.5). Systolic pulmonary artery pressure in group 1 (67 +/- 13 mm Hg) was significantly higher than that in group 2 (39 +/- 10 mm Hg) (p less than 0.001). In those with bidirectional shunting, duration of right to left shunting less than 60% of systole was found when pulmonary artery pressure was systemic or less, whereas duration greater than or equal to 60% was associated with suprasystemic pulmonary artery pressures. Serial changes in pulmonary artery systolic pressure, reflected by changes in ductal Doppler velocities, correlated with clinical status in persistent pulmonary hypertension of the newborn. Persistently suprasystemic pulmonary artery pressure was associated with death in five group 1 patients. It is concluded that ductal Doppler velocities can be reliably utilized to monitor the course of pulmonary artery systolic pressures in newborns.

Blood Flow Velocity↗

PubMed1991

Sensitivity and speed of colour Doppler flow mapping compared with continuous wave Doppler for the detection of ventricular septal defects.

Twenty nine patients (aged from three months to 37 years) with confirmed or suspected ventricular septal defects were studied separately by three examiners who used colour flow mapping and imaging, or continuous wave Doppler and imaging, or a combined reference examination. Colour flow mapping identified 19 of the 25 patients with a ventricular septal defect, continuous wave Doppler echocardiography identified 18, and the combined reference examination identified 24. Two of four patients without ventricular septal defect had a false positive result with colour flow mapping and none had a false positive result with continuous wave Doppler examination. During the reference examination continuous wave Doppler identified 24 patients with ventricular septal defects and colour flow mapping identified 23. In two patients a second ventricular septal defect was found by colour flow mapping, and confirmed by continuous wave Doppler. There was no significant difference in time to diagnosis between the two techniques. Colour flow mapping aids identification of multiple ventricular septal defects but is not faster and has lower specificity than continuous wave Doppler. A combination of the two techniques gave the highest sensitivity and specificity.

Adolescent↗

PubMed1991

[Imaging of coronary arteries and measurement of coronary flow using transesophageal Doppler echocardiography: a comparison with transthoracic Doppler echocardiography].

Recent advances in Doppler echocardiographic techniques, especially using transesophageal approach, enable us to observe coronary arteries and their blood flow. However, the advantages of transesophageal approach in the evaluation of coronary artery are indistinct. The aim of this study was to examine the ability of transesophageal Doppler echocardiography (TED) and transthoracic Doppler echocardiography (TTD) to visualize coronary artery and measure its flow. The study population consisted of 17 healthy subjects and 41 patients with heart diseases (arrhythmia in 2, valvular disease in 10, ischemic heart disease without complete or subtotal obstruction of coronary artery in 22, congenital heart disease in two, cardiomyopathy in four, and infective endocarditis in one). Thirty subjects were examined by TED, and 44 subjects were examined by TTD. Two patients with complete obstruction of the proximal right coronary artery (RCA), who were not included in the above-mentioned subjects, were examined by TED. The results were as follows: 1) The detection rate of coronary arteries by TED and TTD were: left main trunk (LMT); 96.7/86.4%, left anterior descending artery (LAD) and left circumflex artery (LCx); 83.3/56.8%, and RCA; 63.3/38.6%, respectively. 2) Visible length from the orifice: LMT to LAD; 22.2/30.8 mm, RCA; 20.4/22.3 mm. 3) The detection rate of coronary flow by pulsed Doppler of the two methods: LMT; 66.8/0%, LAD; 70.0/31.8%, LCx; 6.6/0%. RCA; 26.7/0%. 4) Coronary flow was detected by transesophageal two-dimensional Doppler in 73.3% of LMT, 76.6% of LAD, 6.6% LCx and 43.3% of RCA. 5) RCA flow was not detected by transesophageal two-dimensional Doppler in two patients who had complete obstruction of the proximal RCA although RCA near the orifice was obviously imaged by two-dimensional echocardiography. In conclusion, TED had an advantage over TTD in detecting coronary arteries and their blood flow, but TTD had an advantage over TED as to the visible length of coronary artery. When RCA near the orifice was clearly visualized, the absence of RCA flow by TED implied complete obstruction of the proximal RCA.

Arteries↗

PubMed1990

[The ductus arteriosus in healthy newborn infants studied by continuous Doppler guided by two-dimensional Doppler color echocardiography].

To characterize the ductus arteriosus shunt after birth, 53 normal newborn infants (36-41 weeks gestation), appropriate in size for gestational age, were examined using two dimensional Doppler echocardiography directed continuous Doppler for evidence of patent ductus arteriosus. The infants were examined within six hours of birth, and every six-eight hours thereafter until ductus arteriosus shunt could no longer be detected. In 51/53 infants, an adequate examination was possible and ductus arteriosus was detected in every infant using the standard precordial approach. Using two dimensional Doppler echocardiography a yellow-orange-red jet, sometimes blue in the central area, directed at the lateral wall of the pulmonary artery was recorded; using continuous Doppler a diastolic or continuous spectral flow into the main pulmonary artery was recorded. Ductus arteriosus shunt could no longer be detected in 7 infants 12 hours after birth, in 26 infants 12-24 hours after birth, in 11 infants 24-36 hours after birth, in 5 infants 36-48 hours after birth and in 2 infants 48-60 hours after birth. A diastolic spectral Doppler flow was present in 38 infants and became continuous before duct closure in 27 infants. In 13 infants it was continuous at first examination and until the ductus arteriosus closure. Both diastolic or continuous spectral Doppler flow could present a flat waveform profile, or a protodiastolic or protosystolic peak velocity. The shunt peak velocity increased significantly with the age i.e. (1.5 +/- 0.7 m/sec mean and SD-), at first examination, vs 2.3 +/- 0.6 m/sec at last examination before ductus arteriosus closure (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Ductus Arteriosus↗

PubMed1978

Technical aspects of ranged directional doppler: a new doppler method of fetal heart rate monitoring.

A new technique for clarifying the fetal heart Doppler signal (Ranged Directional Doppler) for fetal heart rate (FHR) monitoring has been developed. Ranged Directional Doppler enhances the signals of interest and, in addition, permits a separation of the Doppler signals generated by fast-moving structures of the fetal heart either toward or away from the transducer. The separation of the Doppler signals provides increased clarity and reduced baseline clutter. These Doppler signals may approach the fetal scalp ECG in signal-to-noise ratio, and they may provide a signal that allows more accurate external monitoring of long-term and short-term variability patterns of the FHR.

Doppler Effect↗

PubMed1990

The use of two-dimensional Doppler sonography (color Doppler) in the diagnosis of hydranencephaly.

Hydranencephaly, first described by Cruveilhier, may be defined as a rare condition in which the cerebral hemispheres are replaced by membranous sacs filled with cerebrospinal fluid. Cerebral angiography is especially useful in differentiating hydranencephaly and severe hydrocephalus, massive subdural hygromas and alobar holoprosencephaly, but it is no better than other neuroradiological diagnosis methods in the neonate. This report outlines the diagnostic use of two-dimensional Doppler (color Doppler) in a child with hydranencephaly. Color Doppler was performed using an SSA-270A (Toshiba) with a 3.75 MHz phase-array sector scanning probe and no sedation. In this study, color Doppler demonstrated the internal carotid artery in the proximal portion, but the secondary and tertiary branches were not observed. In summary, color Doppler permitted early, easy diagnosis of hydranencephaly. In addition, the use of color Doppler was beneficial in diagnosing other anomalies of the central nervous system in neonates.

Blood Flow Velocity↗

PubMedDate not supplied

Noninvasive angiography for the diagnosis of vertebral artery disease using Doppler ultrasound (vertebral artery Doppler).

A transoral noninvasive procedure in the oropharynx using local anesthesia was applied to detect flow in the vertebral arteries with a bidirectional continuous-wave Doppler ultrasound system. Common carotid artery compression was used to identify the vertebral artery. Flow direction, amplitude of flow signals, diastolic flow, and reaction of flow on common carotid artery compression served as diagnostic parameters. The procedure was applied in 90 patients of whom 42 underwent angiography. The method has proved to be 82% accurate. It was most reliable in the diagnosis of occlusion or aplasia, subclavian steal and normalcy, and was less reliable in the detection of stenosis or hypoplasia of a vertebral artery. Eleven patients with subclavin steal, five patients with a missing vertebral artery three patients with hypoplasia or stenosis, and 15 patients with normal angiorgraphical findings were correctly diagnosed by Doppler; normal Doppler findings were present in three patients with a mission or stenosed vertebral artery. Those patients (five) with Doppler indications of subclavian steal (one patient), missing vertebral artery (two patients), or stenosis (two patients) had normal angiograms. Application of the Doppler procedure, after 11 subclavin endarterectomies, informed the surgeon immediately about the hemodynamic effect of surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.

Cerebral Angiography↗

PubMed1990

[Carotid dissection. Study of 28 cases. Contribution of Doppler exploration, ultrasonic diagnosis and Doppler color echography].

Carotid dissections often go undetected or are confused with an arteriosclerotic cause; in fact, they rarely require surgical treatment. Twenty-eight extracranial carotid dissections (in 25 patients) without direct cervical traumatism were explored successively by pulsed and duplex Doppler ultrasonography complemented in 10 cases by color Doppler flow imaging and secondarily in all cases by arteriography. Pulsed Doppler (DMS Angiodop 481 with 4 and 8 MHz probes) found severe hemodynamic signs in 93% of cases: 6 occlusions, 11 generally extensive or high tight stenoses and 9 significant slowdowns in carotid and ophthalmic artery circulation. For the same internal carotid artery, duplex Doppler (Ultramark 4 or Sonedap 40 with 5, 7.5 and 10 MHz probes) initially showed 5 occlusions and 2 stenoses (4 with fusiform features), 2 double canal images, 8 internal carotid arteries with tubular features (internal caliber less than or equal to 2 mm) and 2 segmental ectasias. There were only 3 other lesions with arteriosclerotic features, 2 of which were minor. Duplex imaging was thus suggestive in 57% of cases. Color Doppler flow imaging enabled precise visualization of these features, better analysis of occlusions and clear detection of 2 other false canal images. After 2 years of follow-up, Doppler ultrasound showed recanalization in 47% of cases with no anticoagulant complications. These combined ultrasonic explorations would thus appear to be useful for early diagnosis of carotid dissections, for guiding arteriography and for facilitating the monitoring of patients under anticoagulant.

Adult↗