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ULTRASOUND AND COLOUR DOPPLER IMAGING

Ultrasound machine Philips HD11
full bladder

Click here to look at examples

Ultrasound imaging or echography is used since early seventies. High frequency inaudible and harmless sounds are emitted through a piezoelectric crystal installed in a probe; contact with skin is ensured by a transmission gel. These sound waves are transmitted at variable speeds through different body tissues. A part of these emitted sounds are reflected by tissue interfaces (acoustic impedance differences) and hit back the probe, which acts simultaneously as a receptor. These signals are computed to form an image visible on the monitor as a slice cut through the examined region. Electronic scanning of the probe many times per second allows dynamic viewing when probe is moved, or observation of spontaneous events inside the body when probe is hold still.

This tool is particularly useful for diagnosis of abdominal diseases (children and adults), foetus survey, neonate brain, small parts (muscle, joints, breast, etc.). It is also essential to guided punctures, in which ultrasound shows in real time with high precision needle progression through tissues.

Doppler mode analyses frequency shifts generated when an ultrasound wave reflects on moving particles (red blood cells); the blood flow of arteries and veins is seen on a flow curve (pulsed Doppler) and its speed parameters are analysed to demonstrate stenoses, accelerations, turbulence or obstruction. Colour Doppler allows direct visualisation of flow within vessels with directional colour information, or as an intensity-related colour (Power or Energy Doppler).

Philips HD11 with up to date technology: harmonics, panoramic view, Sono-CT, 3D/4D, Xres, high resolution probe for small parts, high sensitivity Doppler, contrast agent technique.

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