Graphs
Understanding Ultrasound
Physics
Chapter 1 the basics
• The horizontal axis of a graph runs from
side to side and is referred to as the x-axis
• the vertical axis of a graph runs up and
down and is referred to as the y-axis
Unrelated: items that have not
association
Definition of terms important to
the understanding of ultrasound
physics
Directly related or
Directly proportional
Items that are associated.
When one goes up the other does as
well
• Age to wisdom
• place of birth to shoe size
Directly related or
Directly proportional
• The size of ones foot is directly related to
their shoe size.
• The skill of the sonographer is directly
related to their experience
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Related or Proportional
Related or Proportional
Items that have an association
their association however does not
have to be specified
Inversely Related or
Inversely Proportional
When one item increases the other
decreases
•
•
•
•
Dental health is related to flossing
leprechauns is related to St. Patrick's day
Christmas is related to decorated trees
and of course exam scores are related to
studying
Inversely Related or
Inversely Proportional
• The more powerful the car engine is the
worse mpg you will get
• partying time to school grades
Reciprocal relationship
Reciprocal relationship
A relationship that when two items
are multiplied together their sum is
equal to 1
• 5 and 1/5 are reciprocals
• 10 and 1/10 are reciprocals
• Period and frequency are reciprocals
– an ultrasound term to be discussed latter
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Units
Numbers by themselves are
meaningless without some way
attributing them to something
Common units associated with
ultrasound
• Units of length - most often measured in
millimeters, centimeters.
• Units of area - described as cm2
• Units of volume - described as cm2
Conversion of units
Units
• Increased by a factor
– means to multiply a known entity by that number
• 1 meter is the same 100 centimeters
• 1 meter is the same as 1000 millimeters
• 1 inch is the same as 2.54 cm
• decreased by a factor
– means to divide a known entity by that number
Scientific notation what is it?
It is a way of converting a very large
number into one that can be easily
managed
Scientific notation
• 1.0 x 106 is equal to 1,000,000
• note that the notation of 6 is equal to the
number of zeros.
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Exponent Prefix Symbol Meaning
109
Giga
G
billion
106
Mega
M
million
103
kilo
K
thousand
102
101
hecto
deca
Hh
da
hundred
ten
-1
10
deci
d
tenth
10-2
centi
c
hundredth
10
mili
m
thousandth
10-6
micro
u
millionth
-9
nano
n
billionth
-3
10
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