2D echocardiography uses ultrasound waves between 1-20 MHz to generate images of the heart. Ultrasound transducers use piezoelectric crystals to generate and receive ultrasound waves, and different views of the heart are obtained by manipulating the transducer position and orientation. Standard views include the parasternal long and short axis, apical 4-chamber, subcostal, and suprasternal views, which allow visualization of the heart structures and assessment of wall motion.
2. Ultrasound waves
• Sound waves are mechanical vibrations that
can be described in terms of frequency or
Hertz (Hz), ie, the number of repetitions or
cycles per second.
• Other characteristics include wavelength, the
distance between excitations, measured in
mm; and the amplitude of excitation,
measured in decibels (dB).
3.
4. • Medical ultrasound imaging typically uses
sound waves at frequencies of 1,000,000 to
20,000,000 Hz (1.0 to 20 MHz).
• In contrast, the human auditory spectrum
comprises frequencies between 20 and 20,000
Hz.
5. INTERACTION OF ULTRASOUND
WAVES WITH TISSUES
• When ultrasound beam hits the target it can
undergo
• Reflection
• Refraction
• Scattering
• Attenuation – Reduce signal strength
6. ULTRASOUND TRANSDUCERS
• Ultrasound transducers use piezoelectric crystals to
both generate and receive ultrasound waves
• These crystals (quartz or titanate ceramic) alternately
compress and expand the alternating electric current
that is applied, thereby generating the ultrasound
wave.
• Following a brief period of transmission, typically 1 to
6 microseconds, the same crystal also acts as a
receiver.
• When a reflected ultrasound wave impacts the
piezoelectric crystal, an electric current is generated.
10. • 2D image is generated from data obtained
electronically using a phased-array transducer.
• Since each scan line of data requires a finite
period of time for transmission and reception,
the time required to complete each 2D image
is directly related to the number of scan lines.
11. Tomographic View
• Each tomographic view is defined by the
transducer position
• parasternal
• apical
• subcostal
• suprasternal
12. Views
• Views obtained by manipulation of transducer
by combined angulation and rotation
• long axis
• short axis
• four-chamber
• five-chamber.
13.
14. Parasternal long axis view
• Third or fourth left intercostal space,
immediately adjacent to the sternum
15.
16. Right ventricular inflow and outflow-
PLAX
• Infero medial
angulation of
Parasternal long axis
view
• Visualize IVC, RA ,RV, TV
17.
18. Parasternal short axis
• From the parasternal long axis orientation, a 70º
to 110º clockwise rotation of the transducer
• superior and inferior transducer manipulations
permits delineation of the parasternal short axis
views
• base (aortic valve)
• basal left ventricular (mitral valve)
• mid-left ventricular (papillary muscle)
• and apical left ventricular levels
24. MERCEDES BENZ SIGN
All three leaflets of the
aortic valve may be
identified, forming a "Y"
configuration during
ventricular diastole, with
the interatrial septum
adjacent to the
noncoronary cusp.
27. ANALYSIS OF WALL MOTION PSAX
• Slight inferior
angulation of PSAX view
helps in assessing wall
motion abnormalities in
Myocardial infarction
patients
28. Apical 4 chamber view
• Transducer at
apex
• Visualize all 4
chambers
29.
30.
31. Apical five-chamber
• Anterior angulation and
slight clockwise rotation
of the transducer .
• permits imaging of the
left ventricular outflow
tract, right and left
leaflets of the aortic
valve, and proximal
ascending aorta
33. Apical Long Axis view
• Further
counter
clockwise
direction and
anterior
angulation
34. Subcostal view
• obtained with the patient
supine in full inspiration
to bring the heart closer
to the imaging probe and
with the knees bent to
relax the abdominal
musculature
• The transducer is
positioned immediately
below or to the right of
the xiphoid process.
38. Suprasternal notch
• with the patient supine
and the neck extended,
the transducer is placed
in the suprasternal
notch to obtain an
image of the distal
ascending, transverse,
and proximal
descending aorta