The difference between Colour Doppler Velocity Imaging and Power Doppler Imaging.

نویسندگان

  • T Anderson
  • W N McDicken
چکیده

The Doppler effect, which occurs on the reflection of ultrasound from moving blood or tissue, is observed as a shift in frequency of the reflected ultrasound from that of the incident ultrasound. This Doppler shift has been widely used in clinical practice as a means of measuring blood velocity. Two types of Doppler Imaging are often discussed as facilities on ultrasonic scanners, namely Colour Doppler Velocity Imaging and Power Doppler Imaging. In this article the difference between the two will be described and it will be noted that, although both are used in vascular disease, Power Doppler Imaging is not extensively used at present in cardiology. A number of other names are used for these Doppler techniques, for example ’Normal Doppler’ for Colour Doppler Velocity Imaging and ’Energy Doppler’ for Power Doppler. The echocardiographer is obliged to ascertain what exactly each name stands for. Simple Doppler devices that provide velocity information when their beam is directed at a blood vessel have been available for many years. Indeed images can be produced by these devices if a narrow ultrasound beam is slowly moved across a blood vessel and the blood velocity at each position displayed on a screen. However real-time Doppler imaging only became available when a breakthrough was made in fast signal processing. By ’real-time imaging’ we mean the production of several images per second of the scanned region. The fast signal processing rapidly produces values of the mean blood velocity at neighbouring points along the ultrasound beam and allows the beam to be swept quickly to generate a cross-sectional image of regions of blood flow. Static or slow moving tissue does not produce significant Doppler shifts in the reflected ultrasound and is therefore not presented in a Doppler image. Of course a grey shade B-mode image of these tissues is usually combined with the Doppler image. With early instruments, 15 Doppler images per second were typical but now the rate can be in excess of 50 per second.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Echocardiographic Assessment of Left Ventricle Torsion by Tissue Doppler and Velocity Vector Imaging

Introduction Left ventricular (LV) twist is believed to store potential energy and plays an important role in generating diastolic suction. Recent advances in echocardiography techniques have allowed quantification of LV twist. The aim of the present study was to compare LV twist and torsion in healthy human subjects determined by velocity vector imaging (VVI) and tissue Doppler imaging (TDI) a...

متن کامل

Tissue Doppler Imaging versus Conventional Echocardiography in Evaluation of Cardiac Functions in Diabetes Mellitus

Background: Conventional echocardiography and tissue Doppler imaging have been highlighted to diagnose diastolic and systolic heart dysfunction. We aimed to compare tissue Doppler imaging with conventional echocardiography to diagnose heart dysfunctions in diabetes mellitus type 1 (DMT1) patients. <s...

متن کامل

I-44: Color Doppler Imaging in Impotence

Sexual impotent is very common entity and define as inability to induce or maintaining penile erection during sexual intercourse. Studies reveals about 10% of men aged 40-70 years have complete, 17% have mild and 25% have moderate amount of erectile dysfunction. The sexual impotence has different etiology including psychogenic, neurogenic, arteriogenic and venogenic causes. Current studies reve...

متن کامل

The Effect of Bronchial Asthma on Interatrial Electromechanical Delay Coupling Obtained Using Tissue Doppler Imaging

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...

متن کامل

Quantification of aortic regurgitation using high-pulse repetition frequency three-dimensional colour Doppler.

AIMS The aim of this study was to validate and assess the feasibility of a previously described method using multibeam high-pulse repetition frequency (HPRF) colour Doppler to quantify the vena contracta area (VCA) in aortic regurgitation (AR). METHODS Twenty-nine patients with mild to severe AR were studied. Regurgitant volume and fraction measured by magnetic resonance imaging (MRI) were us...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology

دوره 3 3  شماره 

صفحات  -

تاریخ انتشار 2002