Photograph of a multielement transducer that provides an electronic linear scan and represents the first real-time, two-dimensional, echographic system (from Bom et al52 ).
Photograph of an early real-time sector scanner that originated as a modified electric toothbrush.
History of echocardiography
The History of Echocardiography
Raghu kishore Galla
Early Developments in Echocardiography
The importance of echo reflection, the
concept behind echocardiography, was first
demonstrated by Lazzaro Spallanzani (1729–
1799), when he showed that reflected echoes
of inaudible sound enabled bats to navigate.
by the Jaques
Pierre Curie in
1880 came the
ability to create
The first suggestions of locating submerged
objects by echo-reflection probably came after
the Titanic disaster in 1912
Lewis Richardson's suggestion, in 1912, that
an echo-ranging technique could be used to
detect underwater objects was followed by the
development of the SONAR (Sound Navigation
and Ranging). system by Langevin in 1915,in time
to be used for detecting enemy submarines during
World War I
• A variety of subsequent discoveries were made that
culminated in the first patent for ultrasonic,
nondestructive flaw detection, issued to Sokolov in
• Firestone received a patent in 1942 for a somewhat
• Developments in this field accelerated quickly
during World War II, when this application was used
for naval sonar.
• After the end of World War II, numerous investigators sought
peaceful uses for wartime technology.
• Sonar or diagnostic ultrasound was one of many such
• The early devices often used crude, two-dimensional scanning
• There were also A-mode examinations, whereby one merely
looked at the location and amplitude of the returning ultrasonic
signal. Virtually every organ of the body was scrutinized.
• Most of the early work was done by physical scientists. Very
little was reported in the medical literature, and these
investigations had minimal if any clinical impact for many years.
• Wild was probably the first of the early investigators
to examine the heart ultrasonically.
• This work was done primarily with autopsy
• It is interesting that one of his coworkers was Reid,
who went on to make many important
contributions to the field.
• Neither Wild nor Reid was a physician.
• The Austrian K. T. Dussik
was the first to apply
ultrasound for medical
diagnosis in 1941
• He tried to outline the
ventricles of the brain
using echo- transmission,
a principle similar to X-
• Dussik can be regarded
the ‘father of diagnostic
Clinical Cardiac Ultrasound
• The first use of
as we know it
today is usually
credited to Paul
• Edler was a cardiologist practicing at Lund University
in Sweden and was in charge of the cardiology
department of the medical clinic.
• Hertz, who was a physicist, had a long-standing
interest in using ultrasound for the measurement of
• Hertz came from a very famous family. Both his father
and his uncle were internationally known physicists.
One won the Nobel prize in physics and the other was
the man whose name was appropriated to describe
• Hertz was familiar with the work of Firestone, and he
collaborated with Edler to see whether this technique would
be useful in examining the heart.
• Hertz located a commercial ultrasonic reflectoscope used for
• The first person to be examined was himself. He identified a
signal that moved with cardiac action.
• It was with this instrument that the field of echocardiography,
using the time-motion or M-mode approach, began
• One of Edler’s principal medical concerns in those days
was mitral stenosis.
• He concentrated on this application for the ultrasonic
examination that he now called “ultrasound cardiography.”
• He was able to record several signals from the heart, but
identification of these echoes was difficult.
• He described a signal that we now know originates from
the anterior leaflet of the mitral valve. However, initially
he thought that this echo was coming from the back wall
of the left atrium.
• The manner in which he discovered the true identity of
this echo is interesting.
• Edler performed ultrasonic examinations on patients
who were dying.
• He marked the location and direction of the ultrasonic
beam. When the patient died, he stuck an ice pick into
the chest in the direction of the ultrasonic beam.
• At autopsy, he discovered that the beam transected the
anterior leaflet of the mitral valve and not necessarily
the back wall of the left atrium.
One of the earliest M-mode echocardiograms of the mitral valve, recorded by I. Edler and
C. H. Hertz in December 1953. The sensitivity of the transducers used at that time allowed
the recording of echoes from diseased valves only, and not from normal valves
• Edler reported several structures that he identified on
the ultrasound cardiogram.
• He made a film that was shown at the European
Congress of Cardiology in Rome in 1960.
• In this film, he described the mitral valve with mitral
stenosis and several other normal structures, such as
the cardiac valves and the aorta.
• He noted the back wall of the left ventricle.
• There was also a description of a patient with a large
anterior pericardial effusion.
• He wrote a fairly extensive review article that appeared
in Acta Medica Scandinavia in 1961.
• Despite these many ultrasonic findings, the main
application that he thought was practical was the
detection of mitral stenosis.
• He relied entirely on the M-mode diastolic E-to-F slope
for both the qualitative and quantitative diagnosis.
• He also used this measurement to help differentiate
mitral stenosis from mitral regurgitation
• It was not until Harvey Feigenbaum was suddenly possessed
by the notion of cardiac ultrasound that echocardiography
really took hold.
• While at an American Heart Association meeting in 1963, he
placed the transducer of a machine that was advertised to
measure cardiac volumes on his chest.
• What he saw was a similar echo seen by Hertz 10 years
earlier, and that observation literally became a “life-changing
• Thus began his work on echographic detection of pericardial
effusions that culminated in a publication in1965.
• By 1968, Feigenbaum had begun his echocardiography
Dr. Feigenbaum with an early echocardiography machine at the IU School of Medicine.
| Photo courtesty the Krannert Institute of Cardiology
History of the term ECHOCARDIGRAPHY
• The word “echocardiography” has a unique history.
• Edler called the technique ultrasound cardiography(UCG).
• In the early days of diagnostic ultrasound, the only
examination that had any general popularity was detecting an
echo from the midline of the brain to see if it was deviated by
an intracranial space–occupying mass. This examination was
known as echoencephalography.
• If the ultrasonic examination of the brain was
echoencephalography, then the examination of the heart
should be echocardiography.
• The initial concern was that the natural abbreviation for echo-
cardiography would be ECG.
• Obviously, this abbreviation was already being used for electro -
• We could not use the abbreviation “echo” because it didn’t
differentiate between echocardiography and echoencephalo-
• The reason echocardiography was finally accepted as the name
for this procedure was that echoencephalography disappeared.
• Now, the abbreviation (echo) is only used for echocardiography.
None of the other diagnostic ultrasonic procedures uses the word
or term echo.
• In the 1960s, great progress was being made in developing
real-time two-dimensional (2D) echocardiography.
• In fact, it was the combination of sonar technology with
advanced radar circuitry which improved ultrasonic
instrument performance and introduced the prospect of
• After the early pioneering work of J. J. Wild and J. M. Reid
and D. H. Howry and W. R. Bliss in the early 1950s, both
European and Japanese investigators introduced real-time
2D instruments based on different principles.
• The first real-time, two-
dimensional scanner that gained
popularity was developed by
Bom at Rotterdam.
• This was a linear scanner, and it
produced images that were like
seeing the heart through a
• This development was a
breakthrough because it had
demonstrated dramatically the
potential of real-time, two-
dimensional cardiac imaging and
turned out to be one of the
major ultrasonic scanning devices
for non cardiac uses.
• It is somewhat ironic that the linear scanner, which is
one of the most popular diagnostic ultrasound
devices in general ultrasound, is almost never used
for the organ for which it was designed, the heart.
• Griffith and Henry at the National Institutes of
Health came up with a mechanical device that rocked
the transducer back and forth in a somewhat
awkward fashion. It was handheld, but the ability to
manipulate the transducer was very limited.
A)Two-dimensional sector mechanical device using a single crystal developed by
Griffith and Henry.
B) Two dimensional image of the short-axis aortic valve from that system.
Ao indicates aorta; AoV, aortic valve; LA, left atrium; andRV, right ventricle.
• In 1968 R. Gramiak and P. M. Shah described
contrast echocardiography, an accidental
observation during indocyanine green
injections for cardiac out put measurement.
• This technique was extremely helpful in further
identifying and delineating the various cardiac
structures and is presently being refined for
myocardial perfusion studies.
• In the early 1970s, Reggie Eggleton put a Sunbeam®
electronic toothbrush to an innovative use and gave
the world its 1st commercially successful 2 -
dimensional echocardiogram for several years which
enabled the visualization of actual images of the
• The practical use of these instruments, however, was
limited because of the need for a water bath contact,
limited frame rates and large size transducers.
Indeed, the small precordial acoustic windows to the
heart dictate the use of a small transducer.
• The large footprint of the bulky transducer was also
the problem of the linear array system developed at
the Thoraxcentre, but the clinical results with this
instrument nevertheless stimulated the interest of
• It was during the 1970s when the expanding interest in
echocardiography led to striking advances in instrumentation.
• Hence, much effort was expended to transfer continuous M-
mode data to multichannel recorders, which would produce
long, continuous strips of the recorded data
• In keeping with the advances in instrumentation, transducer
design began assuming greater importance.
(A) Sonographer Joan Korfhagen
examining a neonate with an old
Hoffrel unit. Note the reel-to-reel
videotape equipment at the bottom
of the Hoffrel unit, which then could
transfer M-mode data to a
multichannel strip chart recording
(B). EN indicates endocardium; LS,
left septum; and MV, mitral valve
• In 1968, J. Somer had constructed the first electronic phased-
array scanner based on the wave-front theory formulated in
the 17th century by C. Huygens and sonar technology
• In 1974 F. J. Thurstone and O. T. von Ramm constructed their
electronic phased-array scanner similar to the instrument
developed by J. Somer.
• This instrument marked the beginning of the revolutionary
impact of ultrasound on clinical cardiology
• Today, phased-array scanners are the most widely available
imaging instruments and have a greater impact on cardiac
diagnosis than electrocardiography, for which Einthoven was
awarded the Nobel prize in 1924
• The Austrian C. A. Doppler
(1803-1853) worked out the
between the frequency shift
of sound and the relative
motion of the sound source
and the observer, a theory
tested in practice in 1845 by
C. H. D. Buys Ballot (1817 -
1890) in Utrecht
• Investigation of blood flow velocity using Doppler frequency
shifts to measure motion of cardiac structures, and later of the
velocity of red blood cells, started with the work of S. Satomura
and his colleagues in 1957.
• The pulsed-wave Doppler technique was almost simultaneously
introduced by P. N.T. Wells,P. A. Peronneau et al. and D. W.Baker
• The method allowed depth selection for blood flow velocity
interrogation, but the major step forward for its clinical
acceptance was its combination with imaging: the duplex
scanner published by F. E. Barber et al. in 1974
• This development ultimately led to the integration of pulsed-
wave Doppler with 2D phased-array systems and allow blood
flow to be studied at selected regions within the image plane.
• The Bernouilli equation is
now the cornerstone of the
Doppler assessment of
cardiac haemodynamics and
was published by the Dutch
born D. Bernouilli (1700-
1782) in his treatise
‘Hydrodynamica’ in 1738.
• He had formulated the
relationship of the pressure
drop across the inlet of an
obstruction in a flow
channel to the flow rate
• Simultaneously, another major breakthrough in Doppler came
in 1979, when Holen and then Hatle noted that a modified
Bernoulli equation could be used to detect pressure gradients
across stenotic valves and demonstrated that hemodynamic
data could be accurately determined with Doppler
ultrasound—the long-standing notion that cardiologists learn
hemodynamics in the catheterization laboratory was suddenly
• In 1978, the Swiss-born M. A. Brandestini et al. produced a
128-channel digital multigate Doppler instrument, allowing
the imaging of cardiac structures and blood flow in colour and
• Based on similar principles, C. Kasai et al. constructed in 1982
the revolutionary colour Doppler flow imaging system based
on auto correlation detection, providing a non-invasive
angiogram Of normal and abnormal blood flow on a ‘beat-to-
• At present, M-mode, 2D, pulsed-wave, continuous-wave and
colour Doppler flow are all combined in one diagnostic
console, and represent the most comprehensive cardiac
diagnostic modality by providing integrated structural,
functional and haemodynamic information
A. Early duplex scanner combining 2-
dimensional and Doppler imaging.
B. Typical pulsed Doppler data from early
TRANS ESOPHAGEAL ECHOCARDIOGRAPHY
• Although the idea of transesophageal ultrasound to
circumvent chest wall problems dates back to the early 1970s,
clinical application started with anaesthetists using a M-mode
system introduced by L. Frazin et al. in 1976
• The Japanese engineer K. Hisanaga and co-workers first
reported transesophageal 2D imaging with a mechanical
scanning system 1 year later.
• The mono- and biplane electronic phased-array probes
developed by J. Souquet in 1982 and his multiplane probe in
1985 represented the definitive clinical breakthrough of
Examples of transesophageal phased array element transducers mounted on endoscopes.
• As early as 1960, T. Ciezynski mounted a single element
transducer on a catheter to obtain intracardiac echocardiograms,
and 3 years later R. Omoto obtained intracardiac 2D images with a
slowly rotating, single-element transducer mounted at a catheter
• Two years later, N. Bom et al. described a real-time intracardiac
scanner using an electronically phased circular array of 32
elements at the tip of a 9F catheter.
• These developments were discontinued because of limitations of
miniaturization and the striking improvements in precordial
image quality making intracardiac imaging unnecessary.
• Early in the 1980s, cardiothoracic surgeons added
echocardiography to their armamentarium when Marcus
and associates developed the use of the epicardial Doppler
crystal, which could be affixed to a coronary artery at the
time of cardiac surgery to evaluate the physiologic
significance of coronary stenosis in human beings.
• This technique, together with transesophageal
echocardiography, was subsequently used for the intra
operative monitoring of the repair and replacement of heart
valves, for the assessment of corrected congenital defects,
and for the monitoring of wall-motion abnormalities.
• Since the early 1970s numerous investigators Dekker et al,
Matsumoto et al, Geiser et al, Ghosh et al, Nixon et al,Snider
et al, have explored the feasibility of three-dimensional (3D)
• New computer technologies recently have made volume
rendered data which make the display of tissue information
possible even in real-time
• .In the coming years this modality will further strengthen the
diagnostic capabilities of cardiac ultrasound.
Static image of gated 4-dimensional fetal heart image acquisition: left, 4-chamber
view; right, volume-rendered interior of the 4 chambers in the same orientation. LA
indicates Left atrium; LV, left ventricle; RA, right atrium; and RV, right ventricle.
(courtesy of Thomas R. Nelson, Department of Physics and Engineering, University of
California, San Diego, CA).
• In the early days, it could take days for us to
reproduce 3- dimensional images
• Today it is possible to produce real-time 3
dimensional images that are believable by using an
electronic array consisting of thousands of closely
• Finally, intravascular cardiac ultrasound has
become almost routine in some laboratories and
investigative in some but is probably unavailable in
• Most of the applications have been dedicated to
• Much of the early work was performed by Nissen et al as
well as by others in adults.
• It has even been used in pediatric patients who have
undergone transplantation or had Kawasaki disease as well
as in most other structures.
• Again, as the technology improves in association with 3-D
capabilities, it may become more important in the
armamentarium of the cardiologist.
Examples of intravascular ultrasound catheters.
In this short history of cardiac ultrasound, credit
is given to the pioneers of this exciting non-invasive
and cost-effective diagnostic modality. Because of its
versatility of application in a wide variety of health
care environments, the technique will continue to
grow along with advances in digital techniques and
Obviously, within the scope of this
presentation , only the tip of the iceberg of
echocardiography regarding the past, present, and
even the future can be presented.
So much more can be anticipated. The
potential of ultrasonic application is limitless, and
the evolution of echocardiography has been
dramatic, to say the least…