Unit One Test

Diagnostic Radiography

- skull, spine, extremities, GI, GU

- semi-special: nerve block, steroid injection, arthrography (joints), hysterosalpingography (reproductive organs)

- O.R

Computed Tomography

- sophisticated computerized x-ray equipment

- work closely w physicians

- images called slices

- uses x-ray

-gantry

Angiography

3-D rendering

recording of blood vessels

Interventional Radiology / Special Procedures

- everything but the heart

- diagnostic and therapeutic

- blood vessels

- systemic

- vertebral reconstruction

- c-arm

- uses x-ray (FLUOROSCOPY)

Cardiac Cath Lab

- heart

- diagnostic and therapeutic

- blood vessels

- systemic

- vertebral reconstruction

- c-arm

- uses x-ray (FLUOROSCOPY)

I.R. and Cardiac Cath Lab

- good knowledge of advanced x-ray and medical equipment, and computer software programs

- know anatomy and physiology

- work w physicians

Magnetic Resonance Imaging (MRI)

- no x-ray just MAGNETS & RADIO FREQ.

- highly sophisticated imaging equipment

- understanding of computers and anatomy

- work w physicians

- body is electrically conducive

- measured in TESLAS

- images look realistic (creepy)

- called slices

Sonography

- uses sound waves

- know anatomy and pathology

- know software programs

- physicians are tech-dependent

- SONAR

Nuclear Medicine, PET, and SPECT

- know anatomy, physiology, pharmacology, physics, and handling disposal of radioactive material

- patient becomes the source of radiation

- XRAYS are emitted from the patient

- images appear 2D flat , black and gray

PET & SPECT Scan Imaging

- nuclear medicine with CT or MRI tech

- images in color

Radiation Therapy

- in a team (3-4)

- treat (KILL) cancer or eliminate symptoms

- technical skills secondary

- sensitivity and empathy primary

- exceeds diagnostic range

Stream of electrons

Cathode Ray

Cathode

Negative electrode

Anode

Positive electrode

Milliamperes

- add to filament wire

- starts to make them glow

- releases heat and electrons THERMIONIC EMISSION

KVP

- pushes electrons to hit anode

When electrons hit anode they create..?

XRAYS

Milliampere (mA) control?

- quality and density

- high mA, high e, high xray, dark xray

- low mA, low e, low xray, light xray

TIme (s) controls?

- quantity and density

- length of exposure

- more time, more e, more xray, darker xray

- less time, less e, less xray, lighter xray

Kilovoltage (kV) controls?

- quality, penetrating power, energy, density (darkness), contrast (shades of grays)

- high kV, black image

- low kV, light image

Ceiling xray structure

- most common

- moves freely in all directions

- most expensive

Floor to ceiling structure

- multi-directional

- requires more effort to move

C-arm structure

- limitless positions

- robotic and fluid motion

- angiography

Protective Housing

- isotropic (xrays go in every direction)

useful beam

emitted thru the window

leaking radiation

anything else that escapes the protective housing

Protective housing lined with what and why?

- lead

- provides mechanical support

- protects from damage caused by rough handling

Why is there oil in the protective housing surrounding the x-ray tube?

- insulate shock, and dissipate heat

Primary Radiation

useful beam

Secondary Radiation

everything else (contained in housing)

Leakage Radiation

escapes housing

Percentage of electrons that turn into xrays

- 1/100 or 1% of electrons turn into x-ray

What is the x-ray tube made of?

pyrex glass or metal

- vacuumed (no air molecules)

Cathode components

- negative electrode

- filament (2 coils wire)

- Focal Spot Size (small/large fss)

- Focusing Cup

- wires glow

- thermionic emission

- Tungsten metal

Tungsten melting point

3410C or 6170F

Small filament

- 200 mA or less

- better detail

- smaller body parts

Large filament

- 300 mA or more

- larger body parts

- withstand more heat

Focusing cup

- negative charge

- confines electron beam to a small area of the anode

- stronger negative charge than the electrons to force negative electrons closer together

Space-charge effect

- prevents subsequent electrons from being boiled off due to electrostatic repulsion (same charges repel) - Coulomb's Law

- low current mA applied to boil off electrons

- "cloud of electrons"

Anode

- positive electrode

- stationary or rotating

Stationary Anode

- copper anode

- Tungsten target

- high tube current & power not required

- dental and portable x-ray units

- low energy type of x-ray production

Pitting

- created by a constant bombardment of electrons that generally occurs within stationary anodes

Rotating Anode

- produce high-intensity X-ray beams in shorter periods

- electrons hit diff spots of track to increase anode life (spots cool off before hit again)

- 3600 to 10000 RPM

- better for heat dissipation

- higher mA

Target Track

area of disc that electrons strike and converted to x-rays

Disc composed of

tungsten/rhenium and molybdenum and graphite

Tungsten atomic number and melting point

74 (high atomic number)

- higher efficiency

- thermal conduction: better at heat dissipation

- 3410C or 6170F (minimize pitting)

Who discovered x-rays

Wilhelm Conrad Roentgen

Crooke's Tube

Partially vacuumed tube

Cathode ray

Flow of electrons from negative to positive

Barium Platinocyanide

material that glows/ fluoresce

Professor of Physics at University of Wurzburg, Austria

Wilhelm Conrad Roentgen

X-ray discovered on

November 8, 1895

First published radiograph of who and what

Anna Bertha Roentgen, 1896, hand

2nd published radiograph

Albert Von Kolliker (1896)

First x-ray exam of who and where and of what

Eddie McCarthy (1896), Dartmouth, fractured wrist

What was fluoroscopy used for in retail?

shoe box to measure shoe size

Martyr's Memorial

St. George's Hospital, Hamburg, Germany. 359

Thomas Edison's assistant

Clarence Dally

Roentgen's Nobel Prize in Physics

1901

Who discovered fluoroscopy?

Thomas Edison

Radiology

x-rays, radium, radioactive substances

Diagnostic Imaging

X-rays, radium, radioactive substances, sound waves, radio frequencies

Radiologist

Physician who applies radiation

Radiographer

Skilled person who provides patient services by using imaging modalities as directed by a physician

Radiographer AKA

Radiologic Technologist, Imaging Technologist, X-ray Technologist

Radiograph

photographic record produced by x-rays through an object

- physical copy

Image

a recording of x-rays through an object (computer/monitor)

- digital copy

X-rays

a form of electromagnetic energy (photon)

Electromagnetic Energy (Photon)

Having electrical, wave-like properties and magnetic fields

List of electromagnetic Energy (Photon)

long waves, Radio, Microwaves, infrared, visible, ultraviolet, x-rays, gamma-rays

wavelength

distance from crest to crest, valley to valley, one point on the sine wave to the next point

x-ray wavelength

1x10^-10 m

wavelength unit

meters or angstroms

1 angstroms =

1x10 ^-10 m

1 x 10 (-10) m =

1x10^-8 cm

frequency

number of cycles per second (Hz)

1 cycle =

one positive one negative alternation

Speed of Light =

186,000 miles/sec, 3x10^8 m/sec, 3x10^10 cm/sec

Radio wavelength

1x10^3 m

infrared wavelength

1x10^-5 m

What imaging modality utilizes radiation to produce cross-sectional images (slices) of the

anatomy?

CT

What is another name for sonography

ultrasound

What modality uses radio frequencies of magnetic domains to produce cross-sectional

(sliced) images?

MRI

What radiologic modality uses contrast media and sophisticated computer software to

visualize blood vessels (angiogram)

IR

What modality combines the technology of both Nuclear Medicine and Computed Tomography to create cross-sectional (slice) images of the anatomy?

PET Scan (Positron Emission Tomography)

What is the radiographic study of breast tissue called?

Mammography

What modality uses a sensitive scanner to detect radiation emitted from the patient's body?

SPECT

What modality uses radiation levels that exceed the diagnostic range?

Radiation Therapy

Which term best describes a "bundle" of energy?

photon

Which form of energy would be considered the highest on the electromagnetic spectrum?

gamma rays

As wavelength decreases, energy level ______.

increases

As frequency increases, wavelength ______.

decreases