1. Radiology The study of electromagnetic radiation, the movement of photons, and their ability to create an image.

2. Why do we care about Radiology?
Benefits?
Disadvantages?

3. Chapters 1 & 2: The Technical Side of Imaging
Basic concepts that impact x-ray settings:
Fractions, +, -, x
Proportionality
Units of measurement
Metric prefixes

4. Math Matters! Fractions Multiplication “Pieces of the pie”
Numerator/Denominator
Used in technique charts
mA X seconds (fraction)
Multiplication
Used for exposure times
mA X seconds = mAs

5. Proportionality Definition: The relationship between two numbers
Two types: direct & indirect
Direct
1st number is a multiple of the 2nd
Shown as fraction or with a colon
Radiology example?
Medical example?

6. Proportionality Indirect 1st number up = 2nd number down
Product stays the same, but values differ
Radiology example
Inverse square law
Medical example?

7. Length and Time Meter is standard unit Second is standard unit
Thickness of the patient
Distance of x-ray tube to the patient’s body
Second is standard unit
Exposure time
Processing time
Understand metric prefixes
Needed for conversions

8. The Atom & Radioactivity
Atomic Theory
Periodic Table
Atomic Weight
Atomic Structure
Combining Atoms
Organizing Matter

9. History of Atomic Theory
Ancient Greeks:
4 substances
4 essences
Atom = “no division”
Russian guy
Periodic table
Niels Bohr
Atomic theory

10. Atomic Structure Electrons At least one per atom
Maximum electrons = 2n2 (n = shell number)
Electrons
At least one per atom
Held in place by their negative charge
VERY small
Orbit in rings called shells
Limited # in each shell
Can be added or subtracted
Outer shells may be unstable
Electron binding energy

11. Atomic Structure Protons: Neutrons: Positively charged
Found in nucleus
Balances (+) with (-)
Determines atomic number (Z)
Important in radioactivity
Neutrons:
Neutral charge
Determines atomic mass (A)

13. Organization of Matter
Atoms  elements  molecules  tissues
Isotopes:
Same atomic number but different mass
Can be stable or unstable
Important in imaging – contrast studies and nuclear medicine
Radioactivity:
Atom lives in an abnormal state of excitement
…but all matter seeks stability
Particles and energy are released & form new atoms

14. Organization of Matter
Ionization:
Lower electron binding energy leads to electrons leaving their shell
imbalance in electrical charge
= Atom is now ionized
Radiology importance?