Test 3 Flashcards
What are the three main parts of fluoro equipment
X-ray tube/ generator
Image intensifier
Video monitoring device
Fluoro generators
3 phase or high frequency; max efficiency
How does an image intensifier brighten image
By converting a low intensity full size image to a high insides minifies image
Input phosphor does what
Take xray to light
Input phosphor is made of
Cesium iodide
What does a photo cathode do
Change light to electrons through the process of photoemission
What is the photocathode made out of
Cesium antimony
What is the potential difference between the anode and photocathode
25-35kv
What does the output phosphor do
Change electrons to bright light
What is the output phosphor made of
Zinc cadmium sulfide
The image from the larger input phosphor is condensed into the smaller output phosphor. Bc the image is emitted from a smaller area it appears to be brighter is the process of what
Minification gain
The formula for mini fixation gain is
(Input/output)^2
A high voltage accelerates electrons from the photocathode and their kinetic energy is increased causing many times more light photons from the output phosphor surface describes what
Flux gain
Formula for flux gain
of output light photons/ #of input xray photons
Factors that affect the brightness of fluoro images
MA
Kvp
Pt ️thickness/ tissue density
Automatic brightness control
What allows fluoro unit to automatically maintain the brightest level of the image for variations of pt ️thickness and attenuation
Abc
Automatic brightness control
What is considered the principle source of medical radiation to US population
Fluoro
How is an image magnified
By changing the voltage on electrostatics lenses which decreases the amount of the input phosphor image sent to the output phosphor
Is mA increased or decreased when usin mag mode
Increased
Increasing pt dose
A decrease in image brightness at the lateral portions
Vingetting
Oldest method of monitoring image from image intensifiers
Mirror optics
The most common method for monitoring the fluoro image
Closed circuit TV monitoring (vidicon)
Uses high speed motion picture camera that records images of fast moving object
Cinefluorography
Uses a spot film camera that takes a static radiograph of the fluoro image
Photoflurospot or spot film camera
Visual inspection to flouro machine is done how often
6mths
Environmental inspection I done how often
6mths
Fluoro equipment should be tested horizontally t/f
False vertical and horizontal
Image field vs radiation field
Checks congruency
Uses a fluoro beam alignment tool
Within 2% o SID
High contrast ️resolution
Test to determine ️resolution present and ability to resolve small thin black and white areas
Took used is a fluoro high contrast ️resolution test tool
Good: 40 center 30 periphery
Low contrast ️resolution
To determine ability to resolve large objects that differ slightly from surrounding area
Tool used low contrast ️resolution test tool
Good when contrast holes and surrounding area is 2%
Fluoro exposure
To demonstrate exposure levels around fluoro unit
Tool used ionization chamber
Good when no exposure is read through curtain
Use stopwatch fluoro for 30 sec with and without curtain use inverse square law
What is a way to track pt exposure with digital imaging
DAP AND KAP
Dose area product and air Kerma product
Meters used in rooms to estimate skin doses
Basic QC procedures for digital
Check CR system (cr reader must be cleaned and image plates should be erased daily)
DR image receptors must be kept clean
Check performance of display monitor
Less than ______% below the ideal exposure can create quantum Mottle
60
All monitors used for interpretation should be tested at least _____
Monthly
Shading uniformity test
T= laser jitter test
️resolution chart = spacial accuracy/sharpness
Circles on side of T= contrast evaluation
Relative sensitivity test= s#’s shouldn’t vary more than 20%
Computer system that manages image to electronic form. A network infrastructure that distributes images within and outside facility
PACS
Electronic medical record
HIS
Electronic medical record specific to the radiology dept
RIS
Exchanges and stores medical information between different systems or different equipment
DICOM - digital image communication in medicine
Histogram graph
X axis =
Y axis =
X= amount of exposure Y= the number of pixels
Used to alter tonal qualities o image by mapping values of exposure intensity to desired brightness. ️Contrast can be adjusted by changing slope, brightness can be adjusted by moving line up or down the y axis
LUT look up table
Measure how well image quality is being displayed (how much information is lost from incoming to display)
DQE detective quantum effluence
Is DQE better with DR or CR
Dr
Percentage of pixel area that is sensitive to the image signal.
Fill factor
Current system have a fill factor of _____%
80
Abscess
Additive
Chest with a sac like structure in left lung
A sac o pus
Atrophy
Destructive
Shoulder joint
Degeneration of cells to tissue or organs
Bowel obstruction
Destructive
KUB with airy bowel
Obstruction of bowel preventing normal transit of waste
Active osteomyelitis
Destructive
Funky toes/ 1/2 a foot
Inflammation o the bone due to infection
Pulmonary edema
Additive
Lung with lower 2/3 white out
Excess fluid in the lungs
Tumor
Additive
Chest with grey spot by aorta
Atelectasis
Additive
Chest with entire right side white out
Collapsed lung
Aseptic necrosis
Destructive
Carpal bones with black arrows
Emphysema
Destructive
Chest with long dark lungs
Bronchiectasis
Additive
Chest with right lung cloudy lower 1/2
Plural effusion
Additive
Chest with right angle whited out left angle clipped
Aortic aneurysm
Additive
Chest with large aorta
Cardiomegaly
Additive
Chest with large heart shadow
Fibrosarcoma
Destructive
Hand with fingers clipped
Aerophaigia
Destructive
KUB minus the pubic symphysis CT IMAGE IN LOWER LEFT
Gout
Destructive
Large great toe
Carcinoma
Destructive
Pelvis with 1/2 deteriated
Chronic osteomyelitis
Additive
Knee
CHF
Additive
Chest with lt written in ink
Pneumonia
Additive
3 CXR
TB
Additive
Chest with cloudy upper right lobe and arrows
Calcified stone
Additive
Bladder shot with huge stone
Osteomalacia
Destructive
Hip
Osteoporosis
Destructive
Hunch back lateral Chest
Osteolytic metastasis
Destructive
Pelvis with yellow arrow
Arthritis
Destructive
Lateral c spine
Pneumothorax
Destructive
Chet with right love collapses
Paget’s disease early stage
Additive
Pelvis with Swiss cheese ala
Pneumoectomy
Additive
Chest with right side whited out
Osteochondroma
Additive
Knee with colliflower
Emphyma
Additive
Chest with 1/2 right side white and cloudy distinctive lateral boarder