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calcification arteries

  Alto diagnostic and therapeutic decisions in patients with
Vascular disease by history and the first guided
Physical examination, the use of neon-
Invasive investigations has
Increased significantly in recent years, mainly as a result of
Technological advances in ultrasound. This paper
Describe the technical research.
Early vascular
In the simplest form of ultrasound, ultrasound is
Transmitted as a continuous beam of a probe containing
Two piezoelectric crystals. Transmission Produces crystal
Ultrasound at a fixed frequency (set by the operator according
The depth of the vessel being examined), receiving and sending
Crystal vibrates in response to the reflected waves and produces year
Output voltage. Conventional B mode (brightness mode)
Ultrasound records ultrasound waves reflected from
Tissue interfaces, and two -dimensional image is constructed
According to the reflective properties of the tissues.
Doppler ultrasound
Ultrasonic signals reflected by the stationary surfaces reserve
As often as they were transmitted, the objective
Doppler ultrasonically underlying principal instrument is the
The frequency of the signals reflected by moving objects: such as red
Blood cell changes in proportion to the speed of the target. The
Doppler ultrasound output of a continuous wave is
Usually presented as an audible signal, so it's a sound Heard
Whenever there is movement of blood in the vessel being
Pulsed ultrasound
Continuous wave ultrasound provides little room for
The restriction of the area of tissue being examined, for any
The sound waves are intercepted by the receiving crystal Shipping
Produce an output signal. The solution is to use pulses
Ultrasound. The researcher can focus on a specific tissue
Plane transmission ultrasound pulse and the closure
When receiving signals, except for a predetermined depth are
Return. This allows, for example, the center of an artery, and
Areas near the vessel wall to turn Examined areas.
Duplex scanners
Year important advance in vascular ultrasound beam
Development of spectral analysis, which defines all the
Full spectrum of frequencies (i.e., blood flow velocities)
Found in the arterial waveform falling in one cardiac cycle.
Normal (" phase ") of the Doppler waveform consists speed
All of the three components which correspond to different phases of
Blood flow: rapid ante grade flow reaching a peak that falls on
Systole, transient flow reversal falling in early diastole, and slow
Falling forward flow in late diastole.
Doppler Examination of an artery distal to a stenos Will
Show characteristic change in the velocity profile: the rate of
The increase is delayed, the amplitude decreases and the transient flow
Recoil in diastole is lost. In severe disease, the Doppler

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