Quality Assurance

Question 1

What is quality assurance?

Answer 1

Recording of common sense procedures to ensure that we produce good quality work at an economic price which is time efficient (in radiology = at the lowest possible dose to the patient)

Question 2

What is the WHO definition of quality assurance?

Answer 2

The organised effort by the staff of a facility to ensure that the diagnostic images produced are of sufficiently high quality so that they consistently provide adequate diagnostic information at the lowest possible cost and least possible exposure of the patient to radiation

Question 3

What do we want in a radiograph?

Answer 3

• High quality work - High quality materials and tools - As short a time as possible to do the job - As low a cost as possible - As low a risk as possible

Question 4

What is the ultimate role of quality assurance?

Answer 4

Care of the patient (it will also save you money)

Question 5

What is quality assurance?

Answer 5

The system Arrangements to ensure quality control measures are effective and that they can lead to relevant change

Question 6

What is quality control?

Answer 6

The individual checks within the system Specific measures for ensuring and verifying the quality of the radiographs produced

Question 7

What is quality audit?

Answer 7

Process of external reassurance and assessment that quality control and quality assurance mechanisms are satisfactory and work effectively

Question 8

Who’s expected to know the principles f quality assurance and quality control applied to both equipment and techniques as stated in IR[ME]R 2000?

Answer 8

People who act as practitioners and/or operators in medical exposures Operators only involved in film processing must also be adequately trained

Question 9

What do chapter 5 guidance notes tell us?

Answer 9

QA programme is mandatory Must be recorded Implementation responsibility of a named person = frequency of operations should be defined, content of supporting records defined and frequency of formal checking of records

Question 10

IPEM report 91: recommended standards for the routine performance texting of diagnostic X-ray imaging systems splits operators into two levels of expertise:

Answer 10

A = can be performed by dental practice staff B = more complex and requires a physicist/engineer

Question 11

What are the essential procedures within a dental radiology QA programme?

Answer 11

Image quality Patient dose and X-ray equipment Darkroom/dayligh hood, image receptors, processing, image viewing Working procedures Training Audit

Question 12

What does a subjective quality rating of 1 (Excellent) mean? What % target has been set for this?

Answer 12

No errors of exposure, positioning or processing 70%

Question 13

What does a subjective quality rating of 2 (diagnostically acceptable) mean? What % target has been set for this?

Answer 13

Some errors, but do not detract from the diagnostic utility of the radiograph 20%

Question 14

What does a subjective quality rating of 3 (unacceptable) mean? What % target has been set for this?

Answer 14

Errors which render the radiograph unacceptable 10%

Question 15

How often should image quality be measured?

Answer 15

Formally every 6 months prospectively (easier) or retrospectively = take corrective action if targets are not being achieved

Question 16

What is recorded in the film reject log?

Answer 16

Book/computer file = can look at trend i.e. chair without headrest = wobbliness - Date - Nature of film fault - Cause and corrective action - Number of repeat radiographs taken - Total number of radiographs in a specific time period (can then calculate % of grade 3 radiographs)

Question 17

What are the initial checks that must be carried out on X-ray equipment?

Answer 17

1. Critical examination (by installer) 2. Acceptance test (before the equipment is used clinically to establish baseline performance = responsibility of legal person… includes measurements to assess representative patient doses) -> in dental hospital = physicists

Question 18

What regular checks need to be performed and by whom?

Answer 18

• Regular service/maintenance checks = engineer - Daily checks - record findings i.e. warning signal, stability of tube head = surgery staff

Question 19

How often should routine tests be carried out?

Answer 19

At intervals not >3 yrs Include diagnostic reference levels Responsibility of legal person Complement regular maintenance checks Annually if problems i.e. assessed dose exceeds dose recommended limits, failure to meet image quality targets, performance weakness identified through QA

Question 20

When is a re-examination report needed?

Answer 20

If equipment is: - Relocated - Modified - Repaired

Question 21

What does an equipment log contain?

Answer 21

*What equipment (IR[ME]R 2000) = name of manufacturer, model number, unique identifier, serial number, year of manufacture and date of installation) *Installation checks- formal written reports *Routine tests- chronological order *Maintenance records *Repairs

Question 22

What checks need to be made for darkrooms/daylight hoods daily?

Answer 22

Cleanliness of work surfaces/daylight hood Film hangers should be clean

Question 23

What checks need to be made for darkrooms/daylight hoods 6-12 monthly?

Answer 23

Light tightness of dark room Check safelights/daylight hood (filter, distance from work surface)

Question 24

What does a dark room/daylight hood need to have?

Answer 24

• Light tightness (no light leaking through the door) - Condition of safelights (ordinary light bulbs covered by orange/red filter, can’t be too high wattage) - Correction filter, no cracks - Distance from work surface

Question 25

Which test do we use to check safe working times?

Answer 25

The coin test

Question 26

What is the coin test?

Answer 26

Coins are put onto a film in darkness

Another coin is exposed every 30 seconds to light = should not be able to see where coin was for at least two or three coins for daylight hood to be safe (need >1 min to avoid fogging of films)

Question 27

How should X-ray films be stored?

Answer 27

• cool dry place - away from sunlight and ionising radiation - store on side - rotate stock (fogged by age = QA of when arrived and used) - careful handling

Question 28

What do we need to check on cassettes and intensifying screens?

Answer 28

Check for light tightness (with age extra oral film clasps can come loose = lets light in = needs repairing or replacing -> if processed film has dark edging)

Question 29

How do we check for film-screen contact (i.e. intensifying screens are meant to be firmly sandwiched and if not = blurry)?

Answer 29

We radiograph a grid (either graph paper placed in cassette between screens/splatter guard), if can see grid lines really clearly = fine but if getting blurry they are not

Question 30

What should we clean screens with regularly?

Answer 30

Proprietary cleaner Harsh cleaners = spoils screens If not cleaned = build up of debris

Question 31

How often do digital image receptors need to be checked?

Answer 31

Every month

Question 32

How are digital image receptors checked?

Answer 32

Visual inspection of plates, check cables and sensors, clean plates if necessary n.b. weakest part is where cable goes into plate

Question 33

How do we check image uniformity?

Answer 33

Every 3 months Use low exposure View with narrow window = place on film a block with different thicknesses to represent the different densities found in the mouth

Question 34

QA of chemical processing:

Answer 34

Make up as recommended by the manufacturer Fill fixer tank first (splashes of fixer into developer = problems = less of an issue if happens with empty developer tank) Operate at correct temp Change or replenish regularly (every 2 weeks & keep records) Monitor for deterioration

Question 35

How do you monitor for chemical solutions for deterioration?

Answer 35

Use a test tool (made at home with lead foil or tongue depressor or special ones from manufacturer) with standard settings/distance = has different densities inside = process film in fresh solutions = reference film = repeat daily using same X-ray machine, distance and exposure settings, starts to look faded, if two steps out from the reference need to replace solutions

Question 36

Which processor checks need to be carried out?

Answer 36

Daily: - check levels of solutions and replenish as necessary - change water in wash tank - run a cleaner film through each morning (sediment settles on rollers overnight) - check for deterioration of chemicals Weekly: - clean rollers Fortnightly: - change chemicals, wash transport mechanisms and tank Every 6 months: - check day-light loader with coin test Annually: Service machine

Question 37

What is a magnifying viewer?

Answer 37

A weird triangular shaped device that you hold against the eye - magnifies section and removes light

Question 38

Light boxes are best viewed when:

Answer 38

Dark surround Keep clean Make sure bulb not flickering

Question 39

How can we check moniters for digital imaging?

Answer 39

use test pattern e.g. SMPTE Every 3 months -> greyscale, distance and angle calibration and resolution

Question 40

Radiation protection file for working procedures:

Answer 40

Local rules (IRR99) = procedural and operational elements essential to the safe use of x-ray equipment Employers procedures (IR[ME]R 2000) = ensuring QA programmes followed, written protocols for all examinations and tasks related to radiation safety n.b. need to keep up to date with regular reviews

Question 41

Training:

Answer 41

Regularly updated register of all staff involved in any aspect of radiography Should include: - Name - Responsibility - Date and training - Recommended date for training review

Question 42

Audit:

Answer 42

Clinical audits and/or peer reviews must be provided for, as appropriate, and may include: - the QA programme associated records - the justification and authorisation of radiographs - the clinical evaluation of radiographs

Question 43

What is the target for Audits?

Answer 43

100% of patient should be examined clinically by a suitably qualified and accredited clinician prior to requesting radiographs