Physics 551 Presentation: Doppler Cooling Zane Shi Princeton University November 6 th, 2007.
Ecocardiography. Doppler ecography.
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Transcript of Ecocardiography. Doppler ecography.
EchocardiographyEchocardiography
Doppler examinationDoppler examination
Assist. Univ. Muresan SimonaAssist. Univ. Muresan Simona
PrinciplePrinciple - - EchographEchographyy
Fig. 1
AT
T- time ( period) =1/F
A- amplitude
Λ – length of the wave
Piezoelectric effectPiezoelectric effect
Appearance of an electric field in certain nonconducting crystals as a result of the application of mechanical pressure. Pressure polarizes some crystals, such as quartz, by slightly separating the centers of positive and negative charge. The resultant electric field is detectable as a voltage. The converse effect also occurs: an applied electric field produces mechanical deformation in the crystal. Using this effect, a high-frequency alternating electric current (see alternating current) can be converted to an ultrasonic wave of the same frequency, while a mechanical vibration, such as sound, can be converted into a corresponding electrical signal
The scheme of an echographyThe scheme of an echography
Wave generator
Beamgenerator
TRANSDUCER
receptor convertor
A/D D/A
memory
monitor
The transducer- the probeThe transducer- the probe
Frontul undei
Fig. 5
Ultrasound wave Ultrasound beam
The transducer- the probeThe transducer- the probe
The transducer- the probeThe transducer- the probe
Scanning methodsScanning methods
The reflection of the ultrasound wavesThe reflection of the ultrasound waves
The refraction of the ultrasound waveThe refraction of the ultrasound wave
The amplitude of theThe amplitude of the
electric impulse is electric impulse is directdirect
proportional with the proportional with the
intensity of the echo.intensity of the echo.
Transducer Electric signal
A Mode - amplitudeA Mode - amplitude
Transducer
Heart
Ultrasound beam
B Mode- brightness B Mode- brightness
Mode A Mode B
M mode - motionM mode - motion
Heart - anatomy B modebrightness M mode
Mod M Mod M
Anatomy of the thoraxAnatomy of the thorax
The principal plans of section used in The principal plans of section used in echocardiographyechocardiography
Left parasternal long axis viewLeft parasternal long axis view
Apical two chamber viewApical two chamber view
Apical four chamber Apical four chamber
viewview
Short axis view of left ventricleShort axis view of left ventricle
Subcostal viewSubcostal view
Mitral Valve M-mode AnalysisMitral Valve M-mode Analysis
Mitral Valve M-mode AnalysisMitral Valve M-mode Analysis
Aortic Valve M-mode AnalysisAortic Valve M-mode Analysis
Aortic Valve M-mode AnalysisAortic Valve M-mode Analysis
Ventricular M-modeVentricular M-mode
Ventricular M-modeVentricular M-mode
Ventricular Wall Ventricular Wall Thickness Thickness
Ventricular Ventricular Chamber Size Chamber Size
Intraventricular Intraventricular Masses Masses
Doppler echographyDoppler echography
2 x f0x s x cos α ΔF=--------------------- c
F 0 = emission frequency;S = speed of the blood cells;C=speed of the ultrasound wave;cos α = the ongle between the wave direction and blood direction.
Doppler echographyDoppler echography
F
F
Normal aspectNormal aspect
Arterial flowArterial flow• High resistanceHigh resistance
• Low resistanceLow resistance
Normal aspectNormal aspect
Venous flowVenous flow• peripheralperipheral
• centralcentral
DOPPLER COLORDOPPLER COLORDOPPLER COLORDOPPLER COLOR
Superficial femural arterySuperficial femural artery
Arterial occlusionArterial occlusion
EmbolismEmbolism
ThrombosisThrombosis
ANEURISMSANEURISMS
Heart - color DopplerHeart - color Doppler
Mitral valve regurgitation - color DopplerMitral valve regurgitation - color Doppler