Ultrasonic Doppler Technique Research Articles

Diagnostic reliability of the percutaneous ultrasonic Doppler technique for vertebral arterial occlusive diseases.

There is little data on the diagnostic reliability of the ultrasonic Doppler technique for vertebral arterial occlusive lesions. Percutaneous vertebral Doppler examination and the vertebral angiograms were compared to determine the diagnostic reliability of this technique in 64 vertebral arteries of 53 patients with cerebrovascular disease. The percutaneous vertebral Doppler findings were quantitatively analyzed using a sound spectrograph and were classified into three types: no flow signal type, poor flow type and normal flow type. In nine patients with the no flow type the angiograms revealed vertebral occlusion or a missing vertebral artery in six, giving a diagnostic reliability of 67%. In 17 patients with poor flow type the angiograms revealed vertebral occlusion or a missing vertebral artery in five, terminal narrowing of the artery in nine, and hypoplasia in two giving a diagnostic reliability of 94%. For all vertebral arteries examined with this technique, including normal ones, the diagnostic reliability was 92% (59/64). Percutaneous vertebral Doppler examination has clinical usefulness as a screening test for occlusive vertebral arterial diseases.

A study of factors affecting blood pressure andangiotensin II in newborn infants

Blood pressure has been measured using the Doppler ultrasonic technique in 144 infants in the first 11 days of life. Venous angiotensin II levels measured by radioimmunoassay were determined in 75 of these babies. Highly significant correlations were found between systolic blood pressure and gestational age and body weight. AII was inversely related to blood pressure and significantly related to birth weight. Babies with respiratory distress were found to be significantly hypotensive and to have markedly raised AII levels.

DOPPLER DETERMINED BLOOD PRESSURE RECORDINGS

Ten children ages 12 months to 14 years were studied to determine the effect of cuff size on blood pressure determined by the Doppler ultrasonic technique compared to blood pressure recordings by the auscultatory method. It was found that Doppler determined blood pressure varied with cuff size as it does with the auscultatory method. Too small a cuff will give an artificially high recording while too large a cuff causes too low a recording. The effect of the large cuff is less marked than the effect of too small a cuff.

Intracardiac flow dynamics with bi-directional ultrasonic pulsed Doppler technique.

1) Intracardiac flows were investigated by bi-directional pulsed Doppler technique with a combined use of the two-dimensional echocardiography. The flow at sampling sites in the heat and great vessels were correctly identified on the two-dimensional echocardiograms. 2) Soundspectrographic analysis of the flow Doppler signals was useful in obtaining information about flow modes and in differentiating flow signals from those of valves. 3) In healthy subjects, intracardiac flow revealed a laminar mode. As a matter of interest, a flow toward the aorta, which is a cranially turned flow, was found at the center and at the outflow tract of the left ventricle from mid to late diastole. 4) In mitral stenosis, the central stream at the stenotic portion exhibited an almost laminar and rapid flow. A good coincidence in flow mode was observed between clinical cases of mitral stenosis and experimental stenosis. 5) Disturbed flows were observed in the following diseased conditions. The diastolic regurgitant flow in the left ventricular outflow tract and mitral inflow in aortic regurgitation, the regurgitant flow into the left atrium and the diastolic mitral inflow in mitral regurgitation, the ejection flow in hypertrophic cardiomyopathy with outflow tract obstruction, and the tricuspid inflow in atrial septal defect. 6) Mechanisms of intracardiac flow dynamics were also discussed.

Doppler ultrasonic flow detection as an adjunct in the diagnosis of patent ductus arteriosus in premature infants

Since ligation of a patent ductus arteriosus in the neonate with idiopathic respiratory distress syndrome seems to improve the clinical condition of the infant, we have attempted to identify those neonates earlier with the noninvasive Doppler ultrasonic technique, recording brachial arterial flow signals. Sixteen patients were studied. In the 5 with reversed brachial flow who were operated upon, ligation of a PDA resulted in improvement and postoperative correction of brachial flow reversal as evidenced by the Doppler ultrasonic technique.

Doppler determined blood pressure recordings: the effect of varying cuff sizes in children.

Ten children ages 12 months to 14 years were studied to determine the effect of cuff size on blood pressure determined by the Doppler ultrasonic technique compared to blood pressure recordings by the auscultatory method. It was found that Doppler determined blood pressure varied with cuff size as it does with the auscultatory method. Too small a cuff will give an artificially high recording while too large a cuff causes too low a recording. The effect of the large cuff is less marked than the effect of too small a cuff.

Anomalous iliac compliance in children with a single umbilical artery.

Arterial compliance (C) has been measured in 18 children known to have had a single umbilical artery at birth. Non-invasive ultrasonic Doppler techniques were used to measure C for the aorta, iliac, and leg arteries. Anomalous compliance was found between the two iliac vessels, and it is suggested that this is the result of haemodynamic stress-induced changes during development. The demonstration that the form of large arteries may be changed by altered haemodynamic stress and that their physiological function is thus affected, may have important implications in the pathogenesis of degenerative disease.

Quantitative detection of cerebral arteriosclerosis by means of the pressure-velocity hysteresis technique.

The quantitative detection of cerebral arteriosclerosis by means of the pressure-velocity hysteresis technique composed of the cerebral blood velocity pattern (blood velocity pattern in the internal carotid artery measured by the ultrasonic Doppler technique) and the cerebral pressure pulse pattern (common carotid arteriogram measured by non-invasive sphygmography) was investigated in 17-normal young males, normal middle-aged males and patients with cerebral vascular disorders. The ratio of blood pressure/blood velocity in the maximum blood velocity was used as a measure of resistance of the blood flow. The resistance of the cerebral blood flow was significantlpy increased in the patients with cerebral vascular disorders compared to that in the normal young males. The resistance of cerebral blood flow in the middle-aged males was prone to be intermediate between the former two. The results suggest that the pressure-velocity hysteresis technique is useful for the quantitative detection of cerebral vascular resistance as well as cerebral arteriosclerosis. Several factors related to the technique were discussed.

Assessment of the capacity of cerebral collateral circulation using ultrasonic Doppler technique.

A new non-invasive method for the assessment of cerebral collateral circulation via the circle of Willis using an ultrasonic directional Doppler flowmeter is described. The technique was found useful in measuring the capacity of cerebral collateral circulation and would be applicable not only in internal medicine but also in neurosurgery.

Transcutaneous determination of aortic blood-flow velocities in man

A transcutaneous ultrasonic Doppler technique for measurement of aortic blood-flow velocities has been developed and compared to more established techniques in order to evaluate its potential usefulness. It is possible by this method to quantitate blood velocity in both the ascending aorta and the aortic arch with ease and reliability. Ultrasonic access to the aorta from the suprasternal notch proved adequate in more than 90 per cent of the normal subjects examined. If further clinical trials prove as encouraging, this technique may be of significant value for patient monitoring and cardiac diagnosis.

Unambiguous measurement of volume flow using ultrasound

A new modality for transcutaneous measurement of blood flow is described. Two ultrasonic pulsed Doppler techniques (Doppler imaging and average Doppler shift detection) are combined to measure net flow across an arbitrary sample plane. This estimate of volume flow is independent of lumen shape, orientation, and velocity profile.

A method for recording intraluminal urine flow (application of ultrasonic doppler technique) (author's transl)

A method for recording intraluminal urine flow (application of ultrasonic doppler technique) (author's transl)

Studies on arterial flow patients - instantaneous velocity spectrums and their phasic changes - with directional ultrasonic Doppler technique.

Studies on arterial flow patients - instantaneous velocity spectrums and their phasic changes - with directional ultrasonic Doppler technique.

Non-invasive measurement of subclavian arterial blood flow as a parameter of cardiac output by the doppler ultrasonic flowmeter.

The subclavian arterial blood flow as a parameter of cardiac output was measured in 7 patients with ischemic heart disease (3 acute myocardial infarction, 3 angina pectoris, 1 variant form of angina pectoris) and 5 normal subjects. The measurement was continuously and non-invasively made, utilizing the Doppler ultrasonic flowmeter technique before, during and after exercise. The exercise was performed in the upright position on a bicycle ergometer for 3 min at the work load of 230Kpm/min. In 3 normal subjects, oxygen consumption at various work loads was also measured by the Douglas bag simultaneously with the subclavian arterial blood flow.In normal subjects, the subclavian arterial blood flow steeply increased soon after the beginning of the exercise and promptly returned to the preexercise level after the termination of the exercise. While in patients with ischemic heart disease, the increase in the subclavian arterial blood flow during the exercise was slow, and the time required to return to the preexercise level was significantly prolonged. Light to moderate exercise under the work load of 230Kpm/min increased both the subclavian arterial blood flow and oxygen consumption nearly in the same ratio. With stronger exercise, the increase in oxygen consumption was by far larger than in the blood flow.Continuous measurement of the subclavian arterial blood flow by the Doppler ultrasonic technique is supposed to be a useful method for the evaluation of cardiac function.

CIRCULATORY EFFECT OF ETHANOL, WITH SPECIAL REFERENCE TO CEREBRAL CIRCULATION

The circulatory effect of jet noise on heart rate, systolic blood pressure and cerebral blood flow was investigated by means of the on-line Doppler ultrasonic technique devised by the author in 20 normal young males, normal elderly males and elderly patients with cerebral vascular disease. The jet noise ranged from 60 dBA to 110 dBA. Heart rate and systolic blood pressure showed slight and transient increase at the level of over 90 dBA. Although the cerebral blood flow was increased at the level of 90--110 dBA, conspicuous dissociation was observed between the vertebral artery and internal carotid artery. The vertebral artery dominant type was more frequent than the internal carotid artery dominant type. Headache and discomfort due to the noise were observed in all the subjects. The above facts suggest that the jet noise induces dysfunction of the autonomic nervous system and various kinds of psychosomatic diseases.

Antenatal Localization of Placenta by Ultrasonic Doppler Technique

A simple, safe and accurate method of localizing placenta by ultrasound is described. The accuracy of this technique is verified by anatomical comparison with the standara procedures. A method is suggested for diagrammatically charting the data collected on Doppler placentography. The study revealed that the ultrasonic Dopplei technique has a uniform reliability of 88.5% in experienced hands. The technique has specific advantages, particularly its simplicity and reproducibility which is superior to most available methods that are more sophisticated and hazardous.

Deep vein thrombosis in a Queensland hospital.

Investigation in the postoperative period of 75 patients by means of the radioiodinated fibrinogen uptake method, by the use of the Doppler ultrasonic flow detector, and by clinical assessment revealed an incidence of deep vein thrombosis of only 12%. This is distinctly lower than has been reported by other investigators using the same techniques both in Australia and elsewhere. It appears from this study and associated work that the Doppler ultrasonic technique is sufficiently accurate to be of value in the clinical diagnosis of significant deep vein thrombosis.

Studies on the peripheral blood flow by ultrasonic doppler technique.

Studies on the peripheral blood flow by ultrasonic doppler technique.

Analysis of flow patterns in blood vessels with the directional ultrasonic doppler technique through a transcutaneous approach.

Analysis of flow patterns in blood vessels with the directional ultrasonic doppler technique through a transcutaneous approach.

Use of a Range-gated, Pulsed Ultrasonic Doppler Technique for Continuous Measurement of Velocity of the Posterior Heart Wall

Use of a Range-gated, Pulsed Ultrasonic Doppler Technique for Continuous Measurement of Velocity of the Posterior Heart Wall