Lesson 2: Film-Screen/Analog Mammography Flashcards
they established guidelines that require using a dedicated unit when performing screen-film mammography
National Councill on Radiation Protection and Measurements (NCRP)
what does NCRP stands for?
National Councill on Radiation Protection and Measurements
the most important ability – understand and master these factors to produce consistent, high contrast, diagnostic images
performance
basic considerations for equipment
- space
- portability
- electrical requirements
- ergonomics
C-ARM:
the range of vertical movement should
accommodate both _____ (approximately _____) and those _____.
tall women; 6 ft; who needs to sit
C-ARM:
minimum range of travel is _____ to _____ cm above the floor
66; 140
C-ARM:
it should rotate at least _____ degrees
180
C-ARM:
the point at which the C-arm connects to the tower/collar should be _____ designed so that when moving from the _____ position to the _____ position, the height does not need to be adjusted
isocentrically; craniocaudal; oblique
the controls on both sides of the C-arm which provides easy access for the technologist to adjust the height of the C-arm and raise and lower the compression device while the client is being positioned
electronic controls
this should be available to the client to maintain a difficult or awkward position
grips or handles
compression device-to-receptor distance should allow adequate space when: (3)
- positioning an obese woman for an oblique view
- magnifying an area in a large breast
- raising the compression device over the needle during preoperative localizations
this area of the unit should remain as small as possible to facilitate positioning of the client’s head for the craniocaudal view and during magnification views
tube housing or face shield
this is used for the vertical movement of the C-arm and the compression device to free the hands of the technologist while positioning
foot controls
FOOT CONTROLS:
the amount of compression exerted by the foot pedal control should be _____
minimal
FOOT CONTROLS:
the final compression of the breast should be done using a _____
hand-controlled device
this permit fast and easy exchange of different size film buckys or cassettes
image receptor support device (ISRD)
IMAGE RECEPTOR SUPPORT DEVICE (ISRD):
both _____ and ______ imaging systems should be available to match the size of the receptor to the size of the breast being imaged
8 x 10 inches or 18 x 24 cm; 10 x 12 inches or 24 x 30 cm
it should be easy to read and to adjust
control panel
CONTROL PANEL:
all units must have _____
automatic exposure control (AEC)
CONTROL PANEL:
when the exposure has ended, the control panel should indicate the _____ used
exposure factor
DENSITY SELECTION:
at least _____ density adjustment steps should be available
nine (9)
DENSITY SELECTION:
there should be a _____ to _____% difference in optical density between steps
10; 15
KILOVOLTAGE:
molybdenum target units: range of at least _____ to _____ kVp in no greater than _____ kVp increments
24; 32; 1
KILOVOLTAGE:
rhodium target units: range of at least _____ to _____ kVp in no greater than _____ kVp increments
28; 38; 1
MILLIAMPERAGE SELECTION:
this may be _____ or _____
fixed; variable
MILLIAMPERAGE SELECTION:
if the mA value automatically decreases while increasing the kVp, it should occur _____ the range of settings routinely used for screen–film mammography – the _____ to _____ kVp range
outside; 25; 30
TIME SELECTION:
the grid is not “caught in motion” when using a grid on a thin adipose-replaced breast
short exposures
TIME SELECTION:
the time setting must surpass the reciprocity law failure of the recording system
long exposures
SOURCE-IMAGE DETECTOR DISTANCE:
standard imaging SID
55 cm
SOURCE- IMAGE DETECTOR DISTANCE:
magnification imaging SID
60 cm
this is required if the equipment has preoperative needle localization capabilities
side-loading cassette holder or bucky
NEEDLE LOCALIZATION CAPABILITY:
the compression device for needle localization either has a series of _____ or a large _____
concentric holes; rectangular cutout
FIELD LIGHT:
brightness of the light source should be _____
160 LUX or higher
FIELD LIGHT:
misalignment of the x-ray/light field can be a maximum of _____ of the SID
2%
ALIGNMENT:
the _____, _____, and _____ must be aligned perfectly at the chest wall edge to ensure that all posterior breast tissue is included
focal spot; compression device; image receptor
ALIGNMENT:
misaligned focal spots are caused by _____ and must be calibratef by the _____
machine defect; service engineer
AUTOMATIC TECHNIQUE SELECTION:
units must have a _____ that indicates the technical factors used
post exposure display
the benefit of this mode is to produce an image using an acceptable length of exposure time to reduce.motion blurring and/or client dose, but without compromising the image quality
automatic technique selection
the benefit of this mode is to produce an image using an acceptable length of exposure time to _____ and/or _____, but without compromising the image quality
reduce motion blurring; client dose
EXPOSURE CONTROL:
the operator can make an exposure only when ______ of the x-ray field
completely outside
RADIATION SHIELD:
equivalent attenuation to at least _____ of lead at 35 kVp or the maximum kVp
0.08 mm
RADIATION SHIELD:
equivalent attenuation to at least 0.08 mm of lead at 35 kVp or the maximum kVp, this is to limit operator exposure to well below _____ based on _____, _____
0.1 mSv/week; 40 patients/day; 5 days/week
this terminates the exposure with a sound or visual indicator
back up timer
suggested limits for back up timer
- minimum: 250 mAs
- maximum: 600 mAs
- magnification mode requirements will be different
this device must maintain consistent optical density darkening of the film regardless of the kVp setting used, thickness of the compressed breast, and/or ratio of glandular-to-adipose components
automatic exposure control
increase mAs = _____ density = _____ contrast = _____ detail = _____ distortion
increase; no effect; no effect; no effect
increase kVp = _____ density = _____ contrast = _____ detail = _____ distortion
increase; decrease; no effect; no effect
increase SID = _____ density = _____ contrast = _____ detail = _____ distortion
decrease; increase; increase; decrease
increase OID = _____ density = _____ contrast = _____ detail = _____ distortion
decrease; increase; decrease; increase
increase patient thickness = _____ density = _____ contrast = _____ detail = _____ distortion
decrease; decrease; no effect; no effect
increase film speed = _____ density = _____ contrast = _____ detail = _____ distortion
increase; increase; decrease; no effect
increase motion = _____ density = _____ contrast = _____ detail = _____ distortion
no effect; no effect; decrease; no effect
safelight filters should be changed _____, every _____ to _____ years, as they deteriorate with time and use
periodically; 1; 2
SAFELIGHT:
filter used and examples
for green light-sensitive films; kodak GBX-2 and wratten 1 or 2
SAFELIGHT:
distance
at least 4 ft. above the work area
SAFELIGHT:
bulb wattage for overhead ceiling fixture
no more than 15 watts
SAFELIGHT:
bulb wattage for closer fixtures
7.5 watts
major factor that influence obtaining a quality radiographic image (3)
- temperature
- humidity
- ventilation
TEMPERATURE:
darkroom
approximately 70°F
TEMPERATURE:
excessive heat = _____
emulsion soften and is more susceptible to scratching
TEMPERATURE:
cooler temperature = _____
emulsion crack and peel
HUMIDITY:
darkroom
between 30 to 50%
HUMIDITY:
too dry (less than 30%) = _____
static marks
HUMIDITY:
too moist (above 50%): ______
small droplets of water from the air may cling to the film and cause the emulsion to clump, image will appear as if misted with ink
VENTILATION:
poor airflow to the processor
streaking and mottling of emulsion
VENTILATION:
poor exhaust ventilation in the darkroom
buildup of chemical fumes, which may lead to chronic headaches and nausea
the darkroom’s nemesis, particularly to darkrooms that process mammographic film
dust
they can obscure an area of minute calcifications, or can mimic cancer, which can lead to misdiagnosis
dust
DUST MANAGEMENT:
shelving for film storage within the darkroom should have _____, without _____; this keeps the amount of space dust can settle on to a _____
doors; protruding handles; minimum
DUST MANAGEMENT:
air conditioning systems should be serviced _____, and filters replaced _____, to avoid emission of
precipitates from within the system
regularly; routinely
PROCESSOR MAINTENANCE:
two rules to obtain maximum quality
- install and operate the processor as the manufacturer suggest
- clean, maintain, and monitor every processor on a routine basis
this is monitored as a part of quality assurance program because improper solution replenishment can be detrimental to film quality
chemical replenishment
CHEMICAL REPLENISHMENT:
chemical tank levels should be checked ______
periodically
CHEMICAL REPLENISHMENT:
the tanks would then need to be _____, _____, and _____, and the _____ cleaned.
emptied; cleaned; refilled; transport roller racks
DEDICATED PROCESSING:
most mammographic film used is _____
single emulsion
DEDICATED PROCESSING:
dedicating a processor specifically for the use of single emulsion films can reduce the risk of _____, and in some instances, as with extended processing, can control the _____ and _____.
processor-related damage; film contrast; speed
DEDICATED PROCESSING:
in a processor that is dedicated to only single-emulsion films, less processor related damage will occur if all the films are fed through the processor in the _____
same orientation
artifacts that occur during the processing procedure, within the processor, by one or more of the processor’s components
this includes roller marks, guide shoe marks, chatter, run back, and more
processing artifacts
PROCESSING ARTIFACTS:
______ or _____ can cause a repeating artifact on films that will run parallel to the direction of film travel
improperly cleaned; worn rollers
PROCESSING ARTIFACTS:
film also demonstrate ______ caused by improperly adjusted guide shoes
guide shoe marks
ENVIRONMENTAL ARTIFACTS:
low humidity = _____
static artifacts
ENVIRONMENTAL ARTIFACTS
high humidity = ______
splotch in the image
ENVIRONMENTAL ARTIFACTS:
improper ventilation of darkroom and processor can cause ______ on entrance rollers that will be transferred onto the film
condensation
the appearance this artifact may vary from one manufacturer to another and one film type to another
film-screen handling artifacts
FILM AND SCREEN HANDLING ARTIFACTS:
bending of film before exposure = ______
minus density artifact
FILM AND SCREEN HANDLING ARTIFACTS:
_____ on the film can also cause artifacts; handle films by the _____ while loading and unloading cassettes
fingerprints; edges
occasionally, something not meant to be imaged will inadvertently show up on the film
in mammography, these could include the patient’s nose, chin or ear, fingers, a necklace, or an examination gown
positioning artifacts