To-and-fro pattern in pulse Doppler wave form has been considered a sign of flow competition at the coronary anastomosis. However, this flow pattern is not sufficient to judge whether there is no construction errors in the anastomosis itself. We report a usefulness of the high-frequency ultralinear transducer when used with pulse Doppler because it allows the visualization of the shapes of the ...

Pulse compression technique combines the high energy characteristic of a longer pulse width with the high resolution characteristic of a narrower pulse width. The major aspects that are considered for a pulse compression technique are signal to sidelobe ratio (SSR), noise and Doppler shift performances. The traditional algorithms like autocorrelation function (ACF), recursive least square (RLS)...

Pulse compression technique is used to enhance radar performance in terms of more efficient use of high power transmitters and increasing the system resolving capability. The polyphase pulse compression codes (P3 and P4) which are derived from linear frequency modulated waveforms have low sidelobes and are Doppler tolerant. To reduce the sidelobes further different types of windows have been us...

AIMS This prospective study assesses the (1) feasibility of quantifying ultrasound myocardial perfusion studies based on the densitometric analysis of digital data and the (2) comparison of pulse inversion, second harmonic and harmonic power Doppler modalities with SPECT. METHODS AND RESULTS Twenty-three patients with suspected ischaemic heart disease had i.v. injections of Tc-Sestamibi and O...

Background Endometrial receptivity is one of parameters which determine the reproductive outcome in in vitro fertilization programs. A good blood supply towards the endometrium is usually considered to be an essential requirement for implantation. Blood vessels of the endometrium can be detected by transvaginal color and pulse Doppler sonography. Color Doppler assessment permits better visualiz...

BACKGROUND In pediatric echocardiography, pulse wave Doppler, and tissue Doppler imaging velocities are widely used to assess cardiac function. Current reference values and Z scores, allowing adjustment for growth are limited by inconsistent methodologies and small sample size. Using a standardized approach for parametric modeling and Z score quality assessment, we propose new pediatric referen...

Objective: Transesophageal echo-Doppler cardiac output as well as arterial pulse contour analyses cardiac output are increasingly used for cardiac output monitoring. No data are available whether both techniques may be used interchangeably in patients undergoing cardiac surgery. Design: Prospective, observational study Setting: Operating rooms of a university affiliated hospital. Patients: 30 p...

This paper derives Cramer-Rao bounds on estimates of the Doppler-shifted frequency of a coherent pulse-train intercepted at a single moving antenna. Such estimates are used to locate the emitter that transmitted the pulse train. Coherency from pulse to pulse allows much better frequency accuracy and is considered to be necessary to support accurate emitter location. Although algorithms for esti...

Background: Asthma is a predisposing factor for the development of atrial fibrillation. Asthma disturbs the electrophysiology in the right and left atrium. The aim of this study was to evaluate atrial electromechanical delay by coupling obtained from tissue Doppler imaging (TDI) in children. Methods: A cross-sectional study was conducted on 50 patients with Bronchial Asthma, compared with 50 hea...