Internal tissue displacement measurement based on ultrasonic wave Doppler signal digital detection and its application to fetal movement monitoring

We have developed a fetal movement monitoring system based on small displacement measurement of internal tissues. When ultrasonic pulses are transmitted to the fetus, the reflected ultrasonic waves which have a Doppler frequency shift due to the fetal movements are detected by using an ultrasonic pulsed Doppler technique. In this paper, we propose a displacement measurement method for internal tissues which is based on the Doppler signal digital detection technique. In the method, the received ultrasonic RF signals are sampled with a sampling frequency of four times higher than the centre frequency of the ultrasonic waves; the Doppler frequency shift signals are derived using digital signal processing. From the detected signals, the internal displacements are estimated using the arc-tangent method. The basic algorithm of the detection method has already been used in the area of blood flow sensing, however, we apply the algorithm to the displacement measurement of internal tissues. The comparison between the proposed method and the conventional method is presented. The fetal movement quantitative monitoring system based on the method which has been constructed is shown.     

Vascular effects of endothelin-1 in stage 21 chick embryos

Endothelin-1 is a very potent vasoconstrictor, but its function has not yet been investigated in the early stage of cardiovascular development. The purpose of the present study was to clarify whether endothelin-1 exerts a hemodynamic effect in stage 21 chick embryos. We measured vitelline artery blood pressure with a servo-null micropressure system and blood flow velocity at the dorsal aorta with a 20 MHz pulsed Doppler velocity meter. The vitelline vessels were directly measured with a microscope video system. While monitoring these parameters, endothelin-1 was infused into a vein by a microinjector and data were collected. Endothelin-1 increased the blood pressure and heart rate, but decreased the dorsal aortic blood flow. Only the vitelline veins with a diameter of between 100 and 200 microm constricted after endothelin infusion, but smaller or larger veins and the arteries did not show any significant change in size, although the resistant arteries could not be measured by this method. In conclusion, endothelin-1 has apparent constrictive effects in the selected vessel in the early stages of cardiovascular development when the endocrine and autonomic nervous systems have not yet developed.     

Transvaginal pulsed and color Doppler sonography for the evaluation of adenomyosis

In an earlier paper, we reported our scoring system for the diagnosis of adenomyosis by gray scale transvaginal sonography. In this study we evaluated 44 benign uterine masses (adenomyosis and myomas) and seven uterine malignancies. We used transvaginal color and pulsed Doppler imaging to determine whether this technique is useful to differentiate adenomyosis from uterine malignancies. The peak systolic velocity and the resistive index of intratumoral vessels were studied. The differences in these parameters for adenomyosis and uterine malignancies were statistically significant. Our results suggest that this technique is useful to differentiate adenomyosis from uterine malignancies.     

Doppler ultrasonography of canine maternal and fetal arteries during normal gestation

Two-dimensional ultrasonography was used in combination with colour-flow imaging and pulsed wave Doppler ultrasonography to study the maternal circulation and the development of fetal vascularization in six Beagles during normal gestation. For the first time, the development of the circulation was demonstrated in the bitch and her fetuses intra vitam. The bloodstream was examined in small uteroplacental arteries, the umbilical artery, the fetal aorta and the common carotid artery. The duration of the study was from week 3 after insemination until birth. Relatively large vessels were detected by cross-sectional ultrasonography, and small vessels were detected by colour-flow imaging. In pulsed wave Doppler ultrasonography, the blood flow was measured and described using the parameters of systolic peak velocity, diastolic peak velocity, end-diastolic velocity, pulsatility index, resistance index, A:B ratio (systolic peak velocity:end-diastolic velocity) and S:D parameter (systolic peak velocity:diastolic peak velocity). The development of the measured parameters is typical and similar to that in humans. The systolic peak velocity of the canine maternal uteroplacental arteries shows important differences in comparison with humans. The pulsatility index, resistance index and A:B ratio decrease in nearly all vessels. Only the fetal common carotid artery has constant pulsatility and resistance indices during gestation. For the first time, the quality and quantity of the normal blood flow have been monitored during the whole of gestation. A normal circulation is fundamental for supplying the fetus adequately with oxygen and nutrients and thus for physiological development. These ultrasonographic results are the basis for further clinical studies.     

Pulsed Doppler sonography for the guidance of vein puncture: a prospective study

Blind deep venous puncture is an invasive procedure with risks of serious complications compromising the availability of veins for future punctures or endangering the patient's life. We designed a new hand-held pulsed Doppler probe for coaxial guidance of the puncture needle and a dedicated pulsed Doppler device displaying the depth of the measurement volume. We used this technique prospectively in two independent centers (the nephrology department and the intensive care unit) involving senior as well as junior staff members. Either the non-Doppler or the Doppler method were randomly selected for subclavian vein catheterization in 100 patients and for internal jugular vein catheterization in 30 patients. The success rate on the first attempt was 86.2% for the non-Doppler method versus 96.8% for the Doppler method (p = 0.03). The failure rate of the non-Doppler method used by junior staff members was 9.2%, reduced to 1.5% (p = 0.05) by secondary use of the Doppler method and/or help from a senior staff member (rescue procedure). Pulsed Doppler guidance reduced significantly the failure rate of venous punctures especially when used by seniors or by juniors after a training period.     

Aborted implantable cardioverter defibrillator shock during facial electrosurgery

A patient with a fourth-generation transvenous implantable cardioverter-defibrillator system nearly received an inappropriate defibrillation discharge while undergoing electrofulguration of keratotic facial skin lesions. The incident was confirmed by analyses of the implantable cardioverter-defibrillator's time/date stamped event log and stored electrogram record. Therapy was withheld by the noncommitted implantable cardioverter-defibrillator as the pulsed electrocautery was not continued beyond the charging period.     

Study of the coronary flow with high resolution transthoracic echocardiography and nondirectional Doppler

Two-dimensional echocardiography allows to evaluate the effect of myocardial ischemia on left ventricular wall motion, but a direct measure of coronary flow by this method is still lacking. The aim of the present study was to evaluate the efficacy of a new, high-resolution echocardiographic equipment designed to image the epicardial and intramural coronary vessels by non directional Doppler. We studied 33 consecutive patients by transthoracic echocardiography in apical projections, to detect one or more segments of the left anterior descending coronary artery by non directional Doppler. Once the coronary artery has been imaged, pulsed Doppler was used to measure coronary blood flow velocity at rest. Peak and mean flow velocities were measured on the diastolic phase of the Doppler spectrum. In 25/33 patients (75.7%) the middle-distal tract of the left anterior descending coronary artery was imaged by non directional Doppler. In 15/33 patients (45.5%) the periapical tract of the left anterior descending coronary artery was imaged along with its perforating branches. In 2 out of 4 patients operated of coronary artery bypass grafting, the anastomosis between the left internal mammary artery and the left anterior descending coronary artery was imaged. In all 25 patients it was possible to measure by pulsed Doppler the coronary velocity flow pattern, characterized by a typical prevalent diastolic component. Peak diastolic flow velocity was 49.98 +/- 17.30 cm/s and mean diastolic flow velocity was 36.52 +/- 11.91 cm/s. The Doppler pattern of the grafted mammary artery was different from the native mammary flow. This new non invasive imaging technique of the coronary arteries promises to expand the field of diagnostic and experimental echocardiography and brings new insight into the pathophysiology of ischemic heart disease.     

Visualization of tumor vessels in hepatocellular carcinoma. Power Doppler compared with color Doppler and angiography

PURPOSE: To assess the visualization of tumor vessels in hepatocellular carcinoma (HCC) by power Doppler sonography. MATERIAL AND METHODS: We examined 40 patients with 47 HCC lesions by means of power Doppler sonography and compared its visualization of tumor vessels with those of color Doppler and angiography. RESULTS: In 38 (81%) of the 47 lesions, power Doppler sonography improved the visualization of tumor vessels compared with color Doppler sonography; in the remaining lesions no significant difference was noted. In lesions located within 7 cm in depth, there was no significant difference between power Doppler sonography and angiography. In 10 (83%) out of 12 small (< or = 2 cm in diameter) lesions and in 11 (85%) out of 13 hypovascular lesions, power Doppler sonography performed considerably better than angiography. In deeper-seated lesions, however, angiography was significantly superior to power Doppler sonography. CONCLUSION: Power Doppler sonography is more sensitive in detecting the fine tumor vessels in most HCCs than color Doppler sonography. In addition, power Doppler sonography can replace angiography in evaluating tumor vascularity in HCCs except in lesions that are deep-seated or located near the heart. In these lesions, angiography can complement power Doppler sonography in demonstrating tumor vessels.     

Validation of new pulsed Doppler echocardiographic techniques for assessment of pulmonary hemodynamics

In preparation for a vasodilator study on chronic obstructive pulmonary disease (COPD), we investigated the reliability of recently described pulsed Doppler techniques for estimating pulmonary artery pressure (PAP) and cardiac output (CO). Our aims were to determine the following: (1) the imaging success rate for pulsed Doppler measurements; (2) the repeatability of the measurements, and interobserver and intraobserver variability; and (3) the accuracy of Doppler compared with catheter measurements. Doppler studies were attempted in 81 patients (cardiac disease [23], COPD [22], sleep apnea [32], and normal subjects [4]). Suitable images were obtained in 68 subjects (84 percent) and in 76 subjects (94 percent) for PAP and CO estimations, respectively. The lowest imaging success rates were in COPD patients (68 percent for PAP and 86 percent for CO estimation). Repeatability of the techniques was assessed in four cardiac patients and three healthy volunteers by performing four replicate studies in each subject over 1 h. Intrasubject coefficient of variation was < 10 percent for PAP and < 5 percent for CO. The intraobserver variability for Doppler estimation of systolic and mean PAP was 5.5 percent and 5.8 percent, respectively. The corresponding values for interobserver variability were 6.7 percent and 6.2 percent. Intraobserver and interobserver variability for "nongeometric" method of estimating CO was 5.1 percent and 5.9 percent, respectively. Agreement was good between catheter-measured and Doppler-estimated PAP in the 27 patients tested (cardiac [19] and COPD [8]) for both mean and systolic pressures (r = 0.96 and r = 0.97, respectively). The correlations between thermodilution and Doppler estimations of CO in eight COPD patients were 0.77 ("geometric" technique) and 0.97 ("nongeometric" technique). We conclude that pulsed Doppler techniques can be used to obtain accurate and reproducible quantitative information on pulmonary hemodynamics in a wide range of patients. Suitable Doppler images can be obtained in more than two thirds of COPD patients.     

Incidence and spectrum of spontaneous neoplasms in Han:NMRI mice of both sexes

Pulsed Doppler ultrasound has been used to characterize distinctive pulmonary venous flow patterns in the normal fetus and child. Changes in these characteristic flow patterns have been related to abnormal atrial and ventricular hemodynamics. We report a case of total anomalous pulmonary venous return diagnosed prenatally because of an abnormal pulsed Doppler echocardiographic flow pattern, even though color flow mapping appeared to demonstrate normal pulmonary venous drainage. This case demonstrates the importance of obtaining pulsed Doppler pulmonary venous flow profiles during fetal echocardiography, especially in cases of complex congenital heart disease.     

Usefulness of Doppler ultrasound in the evaluation of patients with active Crohn's disease

OBJECTIVES: To assess the usefulness of Doppler ultrasound in the evaluation of the vascular changes in the splanchnic circulation and bowel wall described in patients with active Crohn's disease (ACD). DESIGN: We analyzed prospectively with Doppler ultrasound the mean velocity of portal flow, the resistive index (RI) of the superior mesentery artery (SMA) and we looked for vessels within the bowel wall. PATIENTS: 50 patients with ACD and 30 normal individuals. RESULTS: In comparison with normal individuals, patients with ACD showed a statistically significant difference (p < 0.001) in the mean velocity of the portal flow and in the RI of the SMA. In all patients with ACD, vessels could be seen within the bowel wall using the color Doppler ultrasound. CONCLUSION: Doppler ultrasound can be used as a non-invasive method to evaluate the vascular changes which develop in the splanchnic circulation and bowel wall of patients with ACD.     

A case of large neonatal arteriovenous malformation with heart failure. Color Doppler sonography, MRI and MR angiography as early non-invasive diagnostic procedures

We report a case of a large arteriovenous malformation (AVM) of neonatal onset with heart failure. Transfontanel color Doppler sonography revealed abnormal vessels in the early stage of the investigation. Magnetic resonance imaging (MRI) revealed numerous flow voids suggesting abnormal vessels, and magnetic resonance angiography (MRA) disclosed numerous bizarre abnormal vessels. Color Doppler sonography is a convenient and appropriate procedure for the early bedside diagnosis of neonatal AVMs. MRI and MRA can replace cerebral angiography for the diagnosis of neonatal AVMs.     

3-D reconstruction of intracranial vessels using a color Doppler energy method--initial experiences]

Transcranial Doppler sonography and colour Doppler imaging provide good information on the basal arterial brain vessels, but cannot provide images comparable to angiographic images. However, comparable displays could be achieved by a 3-dimensional calculation of images collected by a computer. These images of intracranial vessels are supplied by the new Doppler imaging modality Colour Doppler Energy (CDE). Tilting of the acquired data can then be oriented analogous to angiography, CT and MRI projections. Initial results with this method are very promising.     

Effect of opioid blockade on insulin and growth hormone (GH) secretion in patients with polycystic ovary syndrome: the heterogeneity of impaired GH secretion is related to both obesity and hyperinsulinism

Amplitude-coded color Doppler sonography (ACD) has become an useful adjunct to gray-scale US and conventional color Doppler sonography (CD) for the assessment of vascular diseases and pathologic conditions that might affect or alter tissue vascularization or perfusion. Basically, all US units that generate conventional color Doppler information through autocorrelation technique are capable of displaying ACD. This technique is also referred to as power Doppler, amplitude-mode color Doppler US, color Doppler energy (CDE), or US angiography. Amplitude-coded color Doppler sonography has already emerged as a valuable adjunct to conventional CD, particularly for evaluating flow in parts of the body where CD signal is weak because of slow flow, small blood vessels, or both.     

Triple procedure with phacoemulsification prior to grafting

OBJECTIVE: To evaluate the value of transesophageal color Doppler echocardiography in the diagnosis of intrathoracic masses. METHODS: Twenty patients with intrathoracic masses were examined by transesophageal echocardiography (TEE), including 12 patients with central lung masses and 8 with mediastinal masses. The neoplasms were explored by two-dimensional realtime ultrasonography, Doppler color flow imaging (DCFI) and pulsed Doppler (PD). The results were compared with computed tomography (CT), operative and pathological examination findings. RESULTS: We were able to identify the size, structure (solid or cystic), anatomic relationship, metastatic lymph nodes and venous carcinoembolus of the masses. Furthermore, the hemodynamic data in the vasculature inside the masses were detected. CONCLUSIONS: As a new method, TEE with Doppler technique is not only valuable in differentiating malignant and benign neoplasms but also useful for preoperative evaluation of the mass resectability in patients with intrathoracic neoplasms.     

Contribution of long axis motion of left ventricular outflow to calculation of left ventricular stroke volume

Stroke volume can be calculated by using noninvasive Doppler techniques. The products of pulsed Doppler stroke distance of left ventricular outflow and left ventricular outflow area can often be used to calculate stroke volume. However, left ventricular outflow also moves longitudinally toward the apex of the ventricle during systole, so that zero velocity flow cannot be detected by the usual pulsed Doppler studies. We evaluated the contribution of these zero velocity flow to the noninvasive estimation of left ventricular stroke volume in 20 patients with left ventricular disease and in 20 age matched healthy controls. Left ventricular stroke distance was calculated by summing the Doppler stroke distance and the outflow long axis motion. The percentage of zero velocity flow for total stroke volume was calculated in each group. Cardiac output was also measured by thermo-dilution technique. The percentage of zero velocity flow for total noninvasive stroke volume in patients with left ventricular disease was 2.5 +/- 1.1 ml (4.0 +/- 1.5%), significantly lower than in normal subjects, 3.6 +/- 1.0 ml (5.5 +/- 1.5%) (p < 0.05). These long axis motions are significantly reduced, especially in left ventricular disease. Amplitudes of the left ventricular outflow long axis motion were correlated with Doppler stroke distance in all (r = 0.54, p < 0.01). In patients with myocardial infarction, stroke volume by thermo-dilution methods and calculated stroke volume showed good correlation both only by Doppler stroke distance (y = 1.044x + 0.547, r = 0.968) and by Doppler and long axis motion (y = 0.989x + 0.521, r = 0.974). Compared with stroke volume measured by thermodilution method, stroke volume calculated only by Doppler stroke distance was underestimated. We thus demonstrated the influence of zero velocity flow on left ventricular outflow both in patients with left ventricular disease and in normal subjects.     

Analysis of blood flow in adnexal tumors by using color Doppler imaging and pulsed spectral analysis

Because of various contradictory reports in the literature and an increasingly urgent need for preoperative evaluation of adnexal masses before laparoscopic surgery, our aim was to disclose if examination by means of color Doppler ultrasound is useful in distinguishing benign from malignant adnexal tumors in our population. Prior to surgery, pulsed color Doppler velocimetry of the adnexal blood supply was performed in a prospective study in 80 patients with benign and 40 with malignant adnexal tumors. Vascularization was equally frequent in both groups of tumors. Blood vessels of benign tumors had a diffuse, intraseptal or intraproliferative location significantly more often and malignant tumor vessels more often exhibited a diffuse, intraseptal or intraproliferative location (p < 0.01). The mean value of RI+/-SD was 0.56+/-0.14 in benign and 0.33+/-0.13 in malignant tumors. The differences in RI between benign and malignant tumors are statistically significant (p < 0.01). In detecting malignant adnexal tumors, the sensitivity of RI < or = 0.40 is 82%, its specificity 97%, positive predictive value 94%, negative predictive value 92% and its accuracy 92%. The analysis of vascularization presence seems not to have any value in predicting the nature of adnexal tumors, and blood vessels arrangement, as well as measured RI < or = 0.40, allows us to predict the presence of malignancy with limited reliability.     

Carotid artery stenosis in patients who have undergone radiation therapy for head and neck malignancy

Although it is established that small and medium sized arteries undergo extensive radiation damage, the effect on large vessels such as the carotid arteries is less well understood. We sought to determine if an increased severity of carotid artery stenosis is present in patients who have undergone radiotherapy for head and neck tumours. 45 patients aged 43-90 years (average 67) with head and neck malignancies treated with radiotherapy underwent colour Doppler ultrasonographic scanning of the carotid arteries. These patients were compared with a population of asymptomatic historical controls. 60% of patients demonstrated stenosis ranging from 21 to 86%. 38% of patients demonstrated a stenosis greater than or equal to 50%. Carotid artery stenosis appears to be increased in patients who have previously undergone treatment with radiotherapy to the head and neck regions compared with controls (p < 0.001). These findings suggest that radiation has an adverse effect on large vessels. Colour Doppler follow-up may be indicated for patients receiving head and neck radiation therapy.     

The clinical investigator as target

Color flow mapping and duplex ultrasonography are a more accurate technique in renal allograft monitoring by combining real time us with pulsed doppler studies of renal vasculature. Doppler spectral analysis, pulsatility and resistive index evaluation are usefull in the diagnosis of renal allograft dysfunction (I.E. rejection, cyclosporine nefroto-city and acute tubular necrosis). Cfm and duplex ultrasonography allow a non invasive and easy evaluation of the whole renal artery and vein in the diagnosis of renal artery stenosis, vein trombosys and A-V fistula.     

The value of colour Doppler ultrasonography for small bowel involvement of adult Henoch-Sch?nlein purpura

Three patients presented with a non-thrombocytopenic purpuric rash on their upper and lower limbs, abdominal pain, diarrhoea, and arthralgia. Grey scale ultrasound showed abnormally thickened walls of the small bowel. Colour Doppler showed blood flow signals in the diseased bowel wall in all patients. Subsequent barium and endoscopic studies showed oedematous bowel loops with petechial lesions. Biopsy from the purpuric rash of the skin demonstrated vasculitis of subdermal small vessels. The clinical diagnosis of Henoch-Sch?nlein purpura was made in each case. This paper describes the efficacy of grey scale and colour Doppler ultrasonography in the assessment of the small bowel involvement of Henoch-Sch?nlein purpura.