1. What is Imaging and Radiation?
#radioactive#overplayed

2. The BASICS
Anatomic imagine began at the turn of the century with Roentgen's discover of x-rays in 1896
Advancements have allowed physicians (scientists) to look inside the body without the trauma and risk of explanatory surgery.

3. Modern Techniques Traditional x-rays Computer Tomography (CT)
Magnetic Resonance Imaging (MRI)
Dynamic Spatial Reconstruction (DSR)
Digital Subtraction Angiography (DSA)
Positron Emission Tomography (PET) optical Coherent Tomography (OCT)
Echo-planar MIR/Ultrasound

4. Radiation Basics
Radiation is energy that comes from a source and travels through any kind of material and through space
Ionizing Radiation produces charged particles (Ions)
Ionizing radiation is produce by unstable atoms; unstable atoms are said to be Radioactive
To reach stability, these atoms give off energy; called Radiation

5. Types of Radiation
One typically encounters one of Three types: Alpha, Beta and Gamma Radiation
Neutron radiation is also encountered in nuclear plants, high altitude flights and emitted from industrial radioactive sources

6. Alpha Radiation
Heavy, very short range particle and actually an ejected helium nuclease
Characteristic;
Radiation Not able to penetrate human skin or clothing
Emitted materials can be harmful to humans
Very short distance; few inches

7. Beta Radiation Light, short range particle, and ejected electron
Characteristics:
May travel several feet in air and moderately penetrating
Can penetrate human skin to germinal layer
May be harmful if deposited internally
Clothing provides some protection

8. Gamma Radiation
Or X-Rays, very long range, penetrating electromagnetic radiation
Characteristics:
Able to travel many feet in air and many inches in human tissue
Sealed radioactive sources that emit gamma radiation and an external hazard to humans
Visible light, radio waves and ultraviolet light
Electromagnetic radiations differ only in about of energy they have
Gamma/X-rays have most energetic
Clothing provides little shielding

9. Radiography or X-Rays

10. Radiography
Radiography, known by most as X-Ray, uses electromagnetic radiation to make images of your bones, teeth, and internal organs
X-rays allow DRs to take pictures inside the body
They Type of X-Ray depends on what part of the body needs examining and the purpose of the scan
Different tissues absorb different amounts of radiation
bones=dense, absorb X-Rays well; Appear White
Soft tissues; skin, fat, muscles and organs allow rays to pass, appear in varying shades of gray
Air appears black; lungs

11. Uses are as follows
Determine whether a bone is chipped, dislocated or broken (Fractured)
Evaluate Joint injuries and bone infections
Diagnose/monitor degenerative conditions; arthritis
Screen for lung and heart disease
Find and treat artery blockage
Diagnose cause of persistent couching or chest pain
Check from broken ribs/punctured lung
Evaluate unexplained abdominal pain
Help locate objects; maybe swallowed by a child
Detect scoliosis
Evaluate infection of the sinuses
Locate dental problems
Detection of Cancer

12. Preparations In general:
Undress area of body needing examination; may wear gown
Remove jewelry, glasses, metal objects; Why?
May need to wear a lead apron; to shield sex organs, Why?
Medium Contrast; Barium and Iodine

13. Results
Image films usually developed or viewed on-screen within minutes
Radiologist typically views and interprets the results
Sends findings to doctor and than explain results
RISKS:
What are some risks?
Amount of radiation exposed to is extremely low—cancer?

14. Looking Ahead X-Ray Technology has highly advanced from 1895
X-ray Technology has specialized its imaging; such as mammography and Computerized Tomography Scanning (CT)
Fluoroscopy; real-time imaging of body on video
X-Ray Therapy: kill cancer cells and shrink tumors
Thoughts?

15. Typically the views of the body by these technologies are:
Transverse
Sagittal or
Frontal sections
Sagittal and Frontal are less difficult to understand; however most CT & MRI images are transverse
Which is why understanding cross-section anatomy is highly important

16. Computerized Tomography (CT)
Patient placed into a scanner and is exposed to a narrowly focused x-ray beam
Radiation not absorbed is called Remnant Radiation
Data is collected by a computer and converted into Pixels (these make a digital picture)
Image Reconstruction is when the computer combines the pixels to form an image (cross-Section)
Takes over pixels to form a single CT Image

18. A Contrast Medium is a dense liquid that prevents the passage of remnant radiation and appears white in a CT image
This process is used to help with hollow organs (Blood vessels) to see contrast
New CT technology is able to produce an image so fast that physiological motions, respiratory or cardiac movements, do not blur the image
Where are the most commonly used?
Chest
Abdomen
Pelvis
Soft tissues of the neck
brain

19. Magnetic Resonance Imaging (MRI)
Patient is placed into a scanner that produces a very powerful magnetic field
Affects the nuclei of the atoms in patient's body to align
Once aligned a Radiofrequency Pulse is used to establish a second field
Data is collected by a computer by sensors to form pixels image reconstruction
Can produces transverse, sagittal or frontal sections
When pulse ends the hydrogen protons release an energy signal to realign with first magnetic field
Time required is called Relaxation Time
Two relaxation times: T1 (1st second image) and T2 (any time)

21. Appearance of Different Tissues in CT & MRI Images
CT Image
T1 MRI Image
T2 MRI Image
Bone
White
Black
Muscle
Gray
Dark Gray
Brain
White Matter
Gray Matter
Fat
Dark Gray to Black
Cerebrospinal Fluid
Blood
Flowing
Non-Flowing
White*
Contrast Media
Not Used
Air-Filled Structures (lungs, stomach, etc.)
black
*Only if iodinated contrast media is present; otherwise appears gray