Basics of
Echocardiography
• Mostafa Eladawy
MD,AFSA
Ultrasound principles
Penetration depth and resolution
Factors affecting ultrasound transmission:
cycle length: (wavelength λ [mm])
frequency: (frequency f [Hz])
Speed: (propagation velocity c [m/s]) in the respective medium
The relationship of these parameters is described by the wave equation:
c=λ×f
λ=c/f
longer wavelengths penetrate further than shorter wavelengths
Image resolution cannot be greater than one wavelength
the higher the ultrasound frequency, the better the image resolution
Types of resolution
• Axial resolution
• Lateral resolution
• Elevational resolution
Modes
1-A mode
2-B mode
3-M mode
4-2D
Echogenicity
Doppler principles
Christian Doppler
The difference between the emitted frequency
and the received frequency is called:
Doppler shift (fd )
• Blood flow V = fd × c/2 × f0 × cos α
• For practical application in Doppler
echocardiography: the emitted frequency (f0)
is known and the velocity of sound (c/2) is
constant at 1540 m/s. Therefore, the velocity
causing the Doppler shift can be calculated by:
V = fd × cos α
PRF (or scale)
Nyquist limit
• Nyquist Limit = Pulse Repetition Frequency / 2
1-PW
2-CW
3-CFM
Angle of beam
Pressure or pressure
gradient?
•∆P = P2-P1 =
2
4(V2
–
2
V1 )
Transducers
Transducers
Manipulation of TEE probe
.
The ASE/SCA 20 Views for a Comprehensive TEE
Exam
Left Ventricle
function
• FS = EDD-ESD
EDD
• FAC = EDA-ESA
EDA
• EF = EDV-ESV
EDV
Left ventricle function
Simpson mode
M-mode
2D Eye balling
TEI index
Regional wall motion
ME 4 chamber view
Trans gastric view
Right ventricle
Size
Contractility
Rt Atrium
LT atrium
LV filling pressure
Mitral valve leaflets
Mitral valve
Stenosis
1-gradient
2-planimetry
3-pressure half time
Regurgitation
1-PISA
2-vena contracta
3-jet area
4-Regurgitant
fraction
5-Indirect indices
Aortic valve
Stenosis
1-gradient
2-planimetry
Regurgitation
1-PISA
2-jet area
3- vena contracta
4-Indirect indices
Tricuspid valve
Stenosis
Regurgitation
Pulmonary valve
Stenosis
Regurgitation
Pulmonary pressure
Pulmonary veins
Shunts
Ascending aorta and LVOT
Descending aorta
IVC and hepatic veins
Recent adavances
3D echo (live and offline)
• TDI
• Speckle Tracking: non-Doppler, angleindependent quantification of myocardial deformation, by
tracking the displacement of the speckles during the cardiac
cycle, strain and the strain rate can be measured offline.
Recommended books
1-Practical approach to transesophageal
echocardiography(Perrino)
2-Core topics in echocardiography (Rob Fenneck)
3-Atlas of multiplane transesophageal echocardiography
(Martin Dunitz)
4-transesophageal echocardiography in anesthesia and
intensive care (BMJ)
5-Pocket atlas of echocardiography (Thieme)
5-Essential echocardiography (Humana press)
Questions??