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Ultrasound
Spring 2009
Student Final
Ultrasound AKA:
1)Diagnostic Medical Sonography
2)Sonography
3)
4) Vascular Sonography
5)Echocardiography
Principles of Diagnostic Ultrasound
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NON- ionizing
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Uses high frequency sound waves
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By giving reflections from parts in the body
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?
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Cost effective
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?
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Can be imaged in sectional, coronal and oblique planes
What makes a good Sonographer?
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Knowledge of detailed anatomy and
Pathophysiology
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3D anatomy
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Good communication
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Be able to work under stress
Repetitive Motion Injuries
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Poor ergonomic habits
 Poor equipment design
 Poor posture
80% have muscloskeletal
injuries
 Shoulder (rotator cuff)
 ?
 Neck
 Lower Back Pain
 ?
 Eyesight problems
Why?
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Sustained pressure and force
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?
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Assisting with patient movement
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?
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Inadequate work breaks
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Overall job stress
Still a Neonate
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Fairly new technology compared with x-ray
First used for navy sonar in World War II
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1940’s
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US waves transmitted and returned
1947 – Through- Transmission
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Used to detect
tumors and
intracranial lesions
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With 2 transducers
opposite sides of the
head
Called throughtransmission
1948 First Ultrasound
Douglas Howry
Contact Compound Scanner
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1957
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Tom Brown and Ian
Donald
Obstetric techniques
Present Day
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Smaller machines
Increased resolution
Real time scanning
Portable
Mobile
Properties of Sound Waves
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Acoustic waves

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Audible sound waves

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Energy that moves back and forth or vibrates at a steady rate
16,000 – 20,000 cycles/sec
Ultrasound waves

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1- 10 million cycles/sec
_____________ mechanical vibrations through a medium

Transmitted by particles of gas, liquid or solid medium
Piezoelectric Effect

AC applied across piezoelectric crystals

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Crystals grow an shrink
Conversion of electrical energy to
mechanical energy
US is produced from a transducer by this
effect
Acoustic Impedance
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Has properties similar to light

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Focused, refracted, reflected or scattered
Dependent on the density and elastic properties of
medium
Velocity of sound

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Sound waves are sent and received
Velocity is different among bone, air and soft tissue

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Poor impedance in air
Pitch and sound waves are picked up by computer
and produce images: based on depths and speeds
Types of
Transducers
Elements of Transducers

Capable of sending
and receiving US
Advantages of US

1. Ultrasound examinations can be non-
invasive

2. Ultrasound methods are relatively
inexpensive, quick and convenient
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3. No harmful effects have been detected
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4. Ultrasound is particularly suited to
imaging soft tissues
Disadvantages of US
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1. The major disadvantage is that the
resolution of images is often limited.
2. Ultrasound is reflected very strongly on
passing from tissue to gas, or vice versa
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3. Ultrasound also does not pass well
through bone
Real Time, Doppler
and Color Flow Doppler
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Real time:
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Doppler
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Multiple rapid image frames per second
Ex: can see pulsative vascular, cardiac structures,
diaphragm motion & peristalsis
Frequency change in laminar or turbulent flow in
vascular structures
Color Doppler
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Assigns a color scale to change in frequency
Red toward transducer and blue away from
transducer
Doppler
Color Doppler
Gallbladder
Gallbladder
Prostate
Prostate
Bladder
Kidney
Abdomen - LUQ
Abdomen - RUQ
Liver
Liver
Spleen
Spleen
Pancreas
Uterus
Uterus
Ovary
Ovary
Breast
Breast
Testes
19 Week Fetus
Heart
Heart