نتایج جستجو برای: pulsed doppler
تعداد نتایج: 79392 فیلتر نتایج به سال:
A new pulsed Doppler mapping technique has been used to measure the severity of aortic valve stenosis. The Doppler examination was performed at the site of the aortic orifice in the parasternal short axis echocardiographic view and the method was based on the detection of the area of systolic flow through the stenotic orifice. This area was derived by planimetry and the measurements obtained by...
To examine whether CBF can be imaged by color Doppler technique, we visualized CBF using a transesophageal color Doppler imaging system. In 36 of 39 patients with normal coronary arteriograms after heart surgery, the LMT and the proximal LAD were clearly imaged by 2-dimensional echocardiography. Among them, CBF was coded mainly in blue in 32 patients, showing that the flow runs from proximal to...
Sixty patients with pulmonary regurgitation were studied by the pulsed Doppler technique combined with two-dimensional and M-mode echocardiography. Patients with pulmonary regurgitation had abnormal Doppler signals just below the pulmonic valve in the right ventricular outflow tract in diastole on the two-dimensional image. These signals were considered to indicate the regurgitant flow. There a...
In this prospective study, duplex Doppler ultrasound was used in 95 consecutive patients with solid breast masses to evaluate the presence of neovascular flow. A positive Doppler signal, i.e., a Doppler shift frequency of more than 1 kHz using a 5 MHz insonating frequency, was found in 34 of 57 patients with a carcinoma, and also in three patients with a benign condition. These results indicate...
OBJECTIVE To study the prevalence and the characteristics of physiological valve regurgitation. DESIGN Pulsed wave Doppler echocardiography, continuous wave Doppler echocardiography and Doppler colour flow mapping were performed prospectively in healthy volunteers. SETTING Echocardiography laboratory in a city hospital. PATIENTS 32 consecutive healthy volunteers (age 21-49 years, mean age...
Non-invasive continuous and pulsed wave Doppler ultrasonography was performed in 102 consecutive patients with clinically ill defined systolic murmurs to differentiate between flow murmurs, mitral regurgitation, aortic stenosis, and ventricular septal defect, as well as to assess the severity of aortic stenosis. Diagnoses with the Doppler method were based on velocity, direction, and duration o...
Noninvasive visualization of blood flow with high frequency Doppler ultrasound has been extensively used to assess the morphology and hemodynamics of the microcirculation. A completely digital implementation of multigate pulsed-wave (PW) Doppler method was proposed in this paper for high frequency ultrasound applications. Analog mixer was eliminated by a digital demodulator and the same data ac...
The primary purpose of this study was to attempt to select, by examination of the time interval histogram (TIH) output of a range gated pulsed Doppler (RGPD), all children with left-to-right shunt at the atrial level from a pool of 57 children. Fifty-four of the children had various forms of acyanostic cardiac disease. A secondary purpose was to identify any associated lesions in those children...
Tissue Doppler imaging (TDI) is effective in assessing right ventricular (RV) function, but the relationship between invasive measurements and RV-TDI remains unclear. We investigated the RV systolic function by using the TDI-derived systolic myocardial (Sa) velocity and myocardial performance index (MPI). Beagles (n = 7) were anesthetized in the right lateral recumbent position. A 3.5-Fr microm...
The applicability of fractal measurements to the ionospheric scattering function considered as a fractal object has already been demonstrated. Nevertheless in the high resolution method, the chaotic behavior of the object analyzed was deliberately restricted to the two dimensions of propagation delay and Doppler shift. Good results were obtained but we also realized that an important part of th...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید