QUALITY CONTROL For the Technologist TECHNOLOGIST RESPONSIBILITIES l
QUALITY CONTROL For the Technologist
TECHNOLOGIST RESPONSIBILITIES l DAILY l Darkroom Cleanliness l Sensitometry Repeat/Reject Analysis l Fixer Retention l l WEEKLY Screen Cleanliness l Viewbox cleanliness l Phantom Imaging l l MONTHLY l Visual Checklist QUARTERLY l l SEMIANNUALLY Compression l Film/Screen Contact l Darkroom Fog l
DARKROOM CLEANLINESS l NEVER: l Carpet a darkroom l Store boxes or cartons and never open l ALWAYS: l Have shelving with doors l Replace filters and service air conditioning l Wipe countertops with damp cloth l Wipe film trays with anti-static solution l Use a black light
SENSITOMETRY l Must use same box of film l Must be performed before clinical films l Check Developer temperature l Flash sensitometric strip on emulsion side l Speed and Contrast Index within +/-. 15 l B+F within +/-. 03 l Developer within +/-. 5 degrees
SENSITOMETRY l When data falls outside of the limits l Trends l Documentation
SCREEN CLEANLINESS l Clean when 3 -4 specks shown l Use Antistatic solution l 4 x 4 rayon or lintless 100% cotton pads l Wipe in circular motion from center out l Let dry l Use one of many tools available to get rid of dust l Check with black light
VIEWBOXES l Clean etc weekly to remove dust, smudges, l Change l Test bulbs every 12 -18 months luminance with light meter (not required by MQSA)
PHANTOM IMAGING l Monitors whole system l Simulates a 4. 5 cm compressed breast l Consists of 6 nylon fibers, 5 oxide specks, 5 tumor masses l Should be performed: l After any service l After changes in chemistry or film l Whenever changes in image quality suspected
PHANTOM PROCEDURE l AEC placed same as a 4. 5 cm breast l 4 mm acrylic disc placed away from objects l Background density: center, 1. 2 OD +/-. 2 l Density difference: . 4 +/-. 05 for films at 28 k. Vp l Chart m. As to evaluate reproducibility (should not vary more than +/-. 15)
PHANTOM ANALYSIS l Must see 4 fibers, 3 specks, 3 masses (10) l Can vary +/-1 but no lower than 10 objects. l Viewed: l By same person l Same time of day l On same viewbox l Under same viewing conditions l Using same type of magnifying lens
VISUAL CHECKLIST l Takes inventory of room to ensure safety, comfort and convenience
FIXER RETENTION l Performed right after daily strip on emulsion side in clear area l Place drop of fixer and let sit 2 minutes (do not expose to bright light) l Blot dry and place on white cardboard l Compare to chart. No more than 5 ug/cm squared (3 on the chart)
REASONS FOR ELEVATED FIXER l Inadequate wash water flow rate l Partially depleted fixer (enough activity for clearing but not enough for hardening) l Insufficiently hardened emulsion retains too much fixer for wash to remove. l RESULT: Degrades stability of image
FIXER CORRECTION l Increase fixer replenishment l Increase water flow
REPEAT/REJECT ANALYSIS l To evaluate reasons films are repeated l Points l Can out insufficiencies, waste improve efficiency
REPEAT ANALYSIS PROCEDURE l Quarterly examined l Films l ACR and at least 250 patients are categorized states number of repeats should be no greater than 5%.
WAKE UP! ITS OVER!
COMPRESSION l Image l Test quality and safety test in both power drive and manual l MQSA states 25 – 47 lb range
How does compression improve quality? l Decrease scatter l Decrease dose l Decrease patient motion l Increase contrast l Increase uniformity of breast tissue l Increase image sharpness by decreasing thickness thus decrease focal spot degradation
COMPRESSION PROCEDURE l Place towel l Place scale l Place friend’s (soon to be enemy’s) breast on top of scale l Compress in power mode until it stops (never mind the screaming of your new enemy) l Compress in manual until it stops (same as above)
COMPRESSION PROCEDURE l Place towel l Place scale l Place several towels on top of scale l Compress in power until it stops l Compress in manual until it stops
FILM/SCREEN CONTACT l Performed on all new cassettes and/or semi-annual l More critical than general radiography l Highlights l Fine areas of decreased sharpness 30 -40 copper wire mesh screen used
FILM/SCREEN CONTACT PROCEDURE l Clean cassettes l Let sit for 15 minutes l Employ 25 -28 k. Vp, no grid, manual mas with. 5 seconds l Paddle all the way up with acrylic l Wire mesh on top of screen
FILM/SCREEN ANALYSIS l. 7 -. 8 OD near chest wall l Stand 3 -6 ft back l If densities over 1 cm appear, clean and retest. l Remove if large density still appears. l Several small densities acceptable.
DARKROOM FOG l Inspect with all lights off l Be aware of luminescent or phosphorescent items l Use radiation exposed film l MQSA states fog should be no >. 05 OD when exposed for 2 min. l Problems usually lie in safelight position or filters
DARKROOM PROCEDURE l l l l Load cassette in total darkness Expose phantom to 1. 0 OD Inspect safelights Turn off lights, inspect Remove film, insert into template emulsion up Expose sections to safelights Run film then measure densities on each side of lines
Safelights l l l l Filters should correspond with green light sensitive film Lamps ~4 ft from work area Wratten 1 or 2, Kodak GBX-2 good examples of filters No >15 watt bulb in overhead fixture No >7. 5 watt in closer fixtures Printing on filter should face out Change filters every 1 -2 years
AIR QUALITY l Temperature: l Humidity: 70 degrees F 30 -50% l Ventilation: for image quality and technologists’ health
PROCESSOR MAINTENANCE l Developer temperature Increase can cause fog l Decrease can result in: l Decrease in film speed and contrast l Higher dose to pt l l Fixer temperature l l Decrease can affect archival of film Wash-water temperature Can cause biological growth in tank l Can affect developer and fixer temps, improper wash l
PROCESSING CONTINUED… l Chemical l Rates replenishment inconsistent when processor left on and not used l Check solution levels
PROCESSING: STANDARD l Typically l Faster used for general radiography cycle time (usually 90 sec) l Developer l Can immersion ~23 sec accommodate single and double
PROCESSING: EXTENDED l Difference from standard is developer immersion time (~45 sec) l “Push” more contrast and speed from the film l Less exposure needed with increase in film speed l Increase in tube life l Downfall is an increase in noise
TYPES OF PROCESSORS l Small desktop l DISADVANTAGES l Straight-through require careful adjustments to replenishment l Developer not sprayed evenly l ADVANTAGES l Cost, small, fewer rollers, two developer stations, l Less chance of oxidation
TYPES OF PROCESSORS l Large stand-alone l DISADVANTAGES l Artifacts from rollers l Space l ADVANTAGES l Agitates chemicals which increases supply of fresh chemicals
ARTIFACTS l Processing l Environmental l Handling l Positioning l Equipment
SENSITOMETRIC STRIP Establishing the baseline l Expose and process 5 strips l Average readings for temporary base l Process one strip per day for 5 days l If strip is out of tolerance, correct and repeat l Watch for trend due to seasoning effect l Average these 5 strips for new base l Baseline maintained unless film, chemistry or processing altered
CROSSOVER l Performed l 10 -12 l Do when changing box of film sheets remaining in old box not perform after processor cleaning
CROSSOVER PROCEDURE l l l l Perform in total darkness Expose 5 old and 5 new Alternate old and new Distinguish old from new Measure steps used in daily QC Average 5 readings from each box Subtract old from new Add/Subtract results to/from original aim values
CROSSOVER RESULTS l Results l If must be within +/-. 10 greater than. 15 difference, contact film manufacturer representative
l(Dudes Prefer) (Sex, Violence and Partying) over (Visiting) (Relatives For) (Christmas Day Feasts. )
QUALITY ASSURANCE l Defined as all those planned and systematic actions necessary to provide high image quality.
QUALITY MANAGEMENT l Part of the management function which determines and controls quality policy. l Making appointments Call back protocol Obtaining previous mammograms Patient education Patient intake Problem solving l l l
QUALITY CONTROL l The set of operations necessary to maintain or improve quality.
QUALITY SYSTEM l Assignment of responsibility l Establishment of standards l Staff training l Proper documentation of procedures l QC of equipment at installation and throughout its life
MQSA of 1992 l As of Oct 1, 1994, all mammography facilities in the U. S. (except those of Dept of Veterans Affairs) were required to be certified by the FDA as meeting mammography quality in order to lawfully continue to perform Mammography. l Goal: to assure that Mammography is safe and reliable to allow detection of breast CA in its earliest most treatable stages.
MQSA REGULATIONS l l To operate lawfully, a mammography facility must be certified by the FDA. In order to be certified, a facility must first be accredited by a federally-approved private nonprofit or state accreditation body. To be accredited, the facility must undergo periodic review of clinical images; surveyed annually by a medical physicist; meet standards for personnel qualifications, equipment QA programs, and record keeping and reporting. Facility must undergo annual inspections.
ACCREDITATION l. A survey form completed by facility l Phantom images submitted to evaluate image quality l Dosimeter visible on phantom and dose measured l Clinical images submitted for evaluation l Once initial paperwork approved, facility submits 30 days of processor QC strips
CERTIFICATION l Awarded by the FDA as providing quality mammography services. l This is awarded upon accreditation by a federally-approved accreditation body: ACR; States of Arkansas, California, and Iowa
RESPONSIBLE INDIVIDUALS l TECHNOLOGIST l RADIOLOGIST l PHYSICIST
Interpreting Physicians Initial Qualifications State license Diagnostic radiology certification OR 3 months of formal training • 60 hours of category I CME in mammography • 240+ mammograms interpreted under direct supervision • • In the 6 months immediately prior to independent interpretation OR ~ If board certified at first allowable time, within the last 2 years of residency ~
Interpreting Physicians Continuing Requirements • Continuing experience ~ • Interpret at least 960 examinations / 24 months Continuing education At least 15 category I CME credits / 36 months ~ At least 6 of the 15 CME units must be in each mammographic modality used ~ • 8 hours of training in each mammographic modality before independent use
Radiologic Technologists Initial Qualifications State license OR certified by FDA-approved body • 40 hours of documented mammography training • Performing at least 25 examinations under direct supervision • 8 hours of training in each mammographic modality to be used •
Radiologic Technologists Continuing Requirements • Continuing experience ~ • Continuing education ~ ~ • At least 200 examinations / 24 months At least 15 CEUs / 36 months At least 6 of the 15 CEUs must be in each mammographic modality used 8 hours of training in each mammographic modality used before independent use
Radiologic Technologists Reestablishing Qualifications • Continuing experience ~ • Complete 25 examinations under direct supervision Continuing education ~ Bring total continuing education credits up to 15 CEUs / 36 months
Medical Physicists Initial Requirements • • • Licensed or approved by a State OR Certified by FDA-approved body Master’s or higher degree in a physical science 20 semester hours of physics 20 hours of documented mammography survey training One facility and 10 units surveyed 8 hours of training in each modality surveyed before surveying independently
Medical Physicists Alternative Initial Requirements* • Licensed or approved by a State OR Certified by FDA-approved body • Maintained active status For physicists who were qualified under the interim regulations
Medical Physicists Alternative Initial Requirements* (cont. ) • Prior April 28, 1999, have: ~ Bachelor’s degree in physical science with at least 10 semester hours of physics ~ 40 hours of documented mammography survey training after earning the bachelor’s degree ~ One facility and 20 units surveyed after earning the bachelor’s degree
Medical Physicists Continuing Requirements • Continuing experience ~ • Continuing education ~ • Survey at least 2 facilities and 6 units / 24 months At least 15 CEUs / 36 months 8 hours of training in any modality before surveying independently
MANUAL l QC MANUAL l QA MANUAL
QA MANUAL l Details of acceptance l Personnel qualifications and documentations. l Department policy l Safety standards l Biohazards
QC MANUAL l The QC manual is pertinent to ease the inspection process. It lists: l Test procedures l Test frequencies l Test standards l Unacceptable results as listed as well as the corrections made for them.
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