INTRO TO IMAGING
The process by which a neutral atom GAINS or LOSES an ELECTRON, thus acquiring a net charge. This type of energy can disrupt the composition of matter, disrupting life processes.
IONIZING RADIATION
Voluntary peer-review process through which an agency grants recognition to an institution for a program of study that meets specified criteria.
ACCREDITATION
Name the 4 requirements for xray production.
1. Vacuum (tube envelope)
2. Source of e- (filament)
3. Method to accelerate e- rapidly (voltage)
4. Method to stop e- (target)
Describe mAs Reciprocity.
Any combo of mA & s producing equivalent mAs values should produce equivalent IR exposures.
(1) X-ray tube/support system
(2) Collimator assembly
(3) X-ray table
(4) Control Console
(5) X-ray generator
(6) Upright IR holding device
- uses REAL TIME imaging and shows INTERNAL ACTIVITIES and VITAL PROCESSES
- has 2 design systems: BELOW THE PT (more common) and ABOVE THE PT (INC img res, DEC pt dose)
- Consists of FLUOROSCOPIC IR (Image Intensifier or Flat-Panel Detector) and separate FLUORO X-RAY TUBE
Name the educational journey to become an MD/DO.
Bachelor's Degree (4yrs), Medical School (4yrs), Residency (3-4yrs)
Process by which a governmental agency (usually a state) grants permission to individuals to practice their profession
LICENSURE
Name the 4 types of radiation, identify which are diagnostic or nondiagnostic.
ABOSRBED RADIATION: radiation absorbed by radiation
SCATTERED RADIATION: travels in a different direction when interacting with pt (NONDIAGNOSTIC)
REMNANT RADIATION: resulting beam that exits the pt, produces the image in IR.
Describe the Inverse Square Law.
The intensity of radiation is INVERSELY proportional to the square of the distance from the source.
2x INC distance = 1/4 DEC intensity of x-ray beam
1/2 DEC distance = 4x INC intensity of x-ray beam
Demonstrate the basic tube movements.
Transverse: travel across patient cross wise
Vertical: travel up and down height wise
Longitudinal: travel up and down patient length wise
Roll/Rotate: angle tube caudally or cephallicaly
All-Locks: move tube in any direction
Swivel: rotate tube around its vertical axis
Describe where Mobile (Portable) Radiography is used.
- Portable radiography is commonplace in Radiology and is used in the ED, surgery suites, and ICU.
Name the imaging modalities that do not utilize ionizing radiation and describe them.
Magnetic Resonance Imaging (MR): uses strong magnetic fields/radiowaves with a computer to generate sectional images of anatomy
Diagnostic Medical Sonography (DMS): use of ultrasound to visualize structures of the body
Voluntary process through which an agency grants recognition to an individual on demonstration, usually by examination, of specialized professional skills
CERTIFICATION
Describe the 3 types of Image Receptors.
FILM (CONVENTIONAL) R/G:
nearly obsolote, uses chemical development of film to expose image.
COMPUTED R/G (CR):
indirect conversion, uses PSP plates and a Cassette Reader
DIGITAL R/G (DR):
direct, uses TFT technology, xray to electrical signal
indirect, uses scintillator, xrays to light to electrical signal
Name and describe the types of SCATTER CONTROL.
BEAM RESTRICTION (COLLIMATING)
- INC collimation = DEC scatter = DEC pt dose
- prevents fog, which DEC image quality
BEAM FILTRATION
- use of attenuating material, alum or copper, btw x-ray tube & pt to absorb weak x-ray photons
- INC filtration = DEC pt exposure
GRIDS
- aluminum plate that absorbs weaker signals
What are the (5) generic controls and (4) key features of the Operating Console/Control?
Controls:
(1) Main power
(2) kVp
(3) mA
(4) Time (s)
(5) Rotor-Exposure switch
Key Features:
(1) ON/OFF
(2) Exposure Factors
(3) Initiate/Terminate Exposure
(4) Audio/Visual indication of X-ray Exposure
What kind of procedures are Portable C-arms mostly used for?
- INTERVENTIONAL PROCEDURES:
Needle Insertions, Orthopedic surgeries, Vascular line placements
The radiographic examination of the BREAST, JOINT SPACES, CORONARY ARTERIES, and the SPINAL CORD.
MAMMO-, ATHRO-, ARTERIO-, and MYELOGRAPHY
- Know yourself.
- Prioritize responsibilities.
- Prioritize activities.
- Plan for self-care.
Describe the difference between RADIOPAQUE and RADIOLUCENT, provide examples.
RADIOPAQUE: blocks xrays, no easilytransversed through material, high attenuation, Ex:bone, lead, most metals (shows up lighter, white)
RADIOLUCENT: allows xrays to easily pass through, low attentuation , Ex: air, CO2, gas (shows up darker, black)
INCREASING mAs also INCREASES ________
INCREASING kVp also INCREASES __________
mAS: # of electrons, IR EXPOSURE, pt dose/exposure, intensity, radiation
kVP: intensity, penetrating ability, energy of beam, scatter radiation, subject contrast, (BONUS: 15% rule)
What are the differences between the Image Intensifier and the Flat-Panel Detector?
II: conventional image receptor, converts LOW energy xrays to visible light images, LOW image quality, can cause blooming, peripheral fall-off, INC pt dose
FPD: aka DR panel, digital IR, uses direct or indirect conversion, INC image quality
Name the features and functions of CT Scanning.
- Take hundreds of SECTIONAL projections (views) of pt anatomy during a single acquisition, through the use of SLIP RINGS
- uses a numerical quantification of differential absorption, called the CT NUMBER.
- Consists of GANTRY (most visible part to pts), OPERATOR'S CONSOLE, PT COUCH, ELECTRONICS CABINET
- INC image quality, DEC pt dose
The differences between TECHNOLOGISTS, TECHNICIANS, and THERAPISTS.
TECHNOLOGIST = HCP that applies knowledge to practical and theoretical procedures.
TECHNICIAN = performs procedures that require attention to technical detail under the direction of an HCP.
THERAPIST = HCP that carries out Tx designed to correct/improve the function of a body part/system.
Name the following:
1. The accreditation agency for radiography programs.
2. The organization that certifies RTs and publishes an yearly registry.
3. The professional organization that represents RTs and provides CE.
1. JRCERT
2. ARRT
3. ASRT
Name the 3 prime factors for exposure
1. mAs = milliamperage-seconds, TUBE CURRENT, controls amount of electrons -> xray photons
2. kVp = kiloVoltage peak, TUBE POTENTIAL, measure of electrical pressure forcing current through the tube
3. SID = source-to-image distance, distance between point of xray emission and IR.
Describe CONTRAST RESOLUTION and GRAYSCALE.
_______ contrast = ______ grayscale which is SHORT SCALE.
_______ contrast = ______ grayscale, which is LONG SCALE.
CONTRAST RESOLUTION: the visible difference in brightness levels in an image
GRAYSCALE: the varying shade of gray in an image based on the level of contrast resolution.
HIGH contrast = LOW grayscale, short scale.
LOW contrast = HIGH grayscale, long scale.
Describe the function and any advantages of the Collimator.
- Controls the SIZE/SHAPE of the x-ray field by changing the LENGTH/WIDTH.
- Also called "CONING DOWN", INC collimation = DEC X-ray field.
- Adv: protects pt from unnecessary radiation exposure, INC image quality
Name the features and functions of MAMMOGRAPHY.
- Images have INC spatial res, DEC contrast res
- R/g imaging of the human breast to detect breast cancer
- Breast tissues = easy to penetrate, uses low kVp values, 20-40 kVp
- Highly regulated by MQSA
Name the imaging modalities that utilize ionizing radiation and describe them.
Radiography (R): uses xrays to create images of the body
Mammography (M): uses low energy xrays to create images of the breast, early detection of breast cancer
Bone Densitometry (BD): uses low and high energy xrays to Dx osteoporosis with DEXA
Nuclear Medicine (NM): uses radiopharmaceuticals for diagnostic/therapeutic purposes, PET Scan
Radiation Therapy (T): uses radiation to Tx patients with cancer
Computed Tomography (CT):able to visualize pt anatomy in various sectional planes by using x-ray beam with the help of a computer
Which of these are symptoms of the Fight-or-Response?
1. Release of hormones
2. INCREASE metabolism
3. INCREASE temperature
4. INCREASE HR & RR
5. DECREASE blood flow to extremities
6. PNS stimulated
1. Release of hormones
2. INC metabolism
4. INC HR & RR
BONUS POINTS:
INC blood flow to extremities, CNS stimulated
Define attenuation and differential absorption. _________ attenuation = _________ absorption of photons = __________ atomic number = _______ IR Exposure
ATTENUATION: drop/reduction of x-ray photons due to scatter/absorption.
DIFFERENTIAL ABSORPTION: difference of absorption rates in different tissues and thicknesses
INC attenuation = INC abs = INC atomic # = DEC IR Exp
Describe SPATIAL RESOLUTION and the different types of DISTORTION.
1. SPATIAL RES: amount of SHARPNESS or DETAIL
2. SIZE DISTORTION (Magnification):
- Caused by changes in SID & OID
SHAPE DISTORTION (Elongation, Foreshortening)
- Caused by CENTRAL RAY ANGULATION and BODY PART ROTATION
- The termination of x-ray exposure based on optimum x-ray energy sense by an SSD.
- Radiation keeps shooting from the x-ray table until it hits the CHAMBERS.
- SIMPLIFIED exposure technique selection, INC consistency of image quality
Name features and functions of MR SCANNING.
- PT is source of signal used to create images
- Pt anatomy is placed in EXT magnetic field sending R/F energy to create PROTON SIGNALS picked up by EXT R/F receivers (COILS)
- Main pt complaints:
CLAUSTROPHOBIA, MR NOISES DURING SCANS (c/b gradient coil vibrations)