1. 20th ISRRT World Congress in Trinidad and Tobago April 2018
Awareness and adherence to Diagnostic Reference Levels : is the use of Digital Radiography changing practice.
20th ISRRT World Congress in Trinidad and Tobago April 2018
Dr. S. Mc Fadden1, ISRRT Dosewise International Radiographer of the Year 2014
Martin Benwell2,Thom Roding3, Geert de Vries3, H Bijwaard3, Jelle Scheurleer3
1 Centre for Health and Rehabilitation Technologies, Institute of Nursing and Health, School of Health Sciences, Ulster University (NI) 2 London South Bank University2 3 Inholland University of Applied Sciences, The Netherlands

2. Overview Background Aims/objectives Methodology Results Discussion
Conclusion
Acknowledgements

3. Background Increased use of Digital Imaging in radiography
Computed Radiography (CR)/Digital Radiography (DR)
Wide exposure latitude of digital systems
Pre and post processing image manipulation
Dose creep
Higher radiation doses than are necessary [1].
Previous studies have highlighted that staff overexpose rather than underexpose patients as this reduces quantum mottle on the image and improves image quality [2, 3].
[1] International Atomic Energy Agency. Avoidance of unnecessary dose to patients while transitioning from analogue to digital radiology. Vienna: IAEA-TECDOC-1667; [2] Gibson DJ, Davidson RA. (2012) Exposure creep in computed radiography: a longitudinal study. Acad Radiol; 19: 458–62. [3] Herrmann TL, Fauber TL, Gill J, et al. (2012) Best practices in digital radiography. Radiol Technol. 84: 83–9

4. Figures 1a-d. http://www. agfahealthcare
20Index%201,%20Indiana%20University_tcm pdf

5. Response of a digital detector to exposure intensity variations
Figure 2 Response of digital detector

6. Impact of Digital Radiography
A report of ‘dose creep’ [4]
20% and 35% of patients in the US are overexposed by at least a factor of two
due to the introduction of CR and DR technology.
Research of equipment from five different suppliers performed with the aid of phantoms [5]
technically possible to both, under and over expose the imaging plates and still be able to process the data to produce an acceptable image quality
More recently, reported that radiographers are not manipulating exposure factors for different sized patients and rely on pre-set exposures with staff openly admitting to “bumping up” their x-ray exposure to ensure a diagnostic image. [6]
[4] Odle, T. (2008) Send the dose creep packing, ASRT Scanner, 40,
[5] Fauber, T.L., (2009) Exposure variability and image quality in computed radiography, Radiologic Technology, 80, 3, pp
[6] Hayre, C.M. (2016) ‘Cranking up’, ‘whacking up’ and ‘bumping up’: X-ray exposures in contemporary radiographic practice, Radiography, 22, (2),

7. What can we do to get the balance right ?

8. Diagnostic reference levels (DRL)
Diagnostic reference levels (DRL) are defined as radiation dose levels for typical x-ray examinations for standard sized patients using standard equipment.
highlight recurrent over or under exposures but they also allow for higher doses to account for such times when a higher dose is required for diagnosis [7].
National DRLs (NDRLs)
Local DRLs (LDRLs)
Where no DRLs are available, DRLs can be based on local dose measurements/practice data, or on published values that are appropriate for the local department.
Diagnostic reference levels were first mentioned by the International Commission on Radiological Protection (ICRP) in and subsequently recommended in greater detail in From the 1996 report:
The Commission now recommends the use of diagnostic reference levels for patients. These levels, which are a form of investigation level, apply to an easily measured quantity, usually the absorbed dose in air, or in a tissue equivalent material at the surface of a simple standard phantom or representative patient.
NDRL for each examination or procedure and patient group are set on the basis of distributions of the typical (median) doses observed in wide scale (national) surveys, commonly by adopting the third quartile value to provide investigation levels for unusual practice (doses in top 25%). 
LDRLs represent the typical local practice at a single large centre or group of healthcare facilities, set as the third quartile of the median doses determined from samples of patients in the different healthcare facilities of the group.
National DRLs (NDRLs) should be set on the basis of wide scale surveys of the median doses representing typical practice for a patient group (e.g. adults or children of different sizes) at a range of representative healthcare facilities for a specific type of examination or procedure. NDRLs are commonly set at the third quartile values (the values that splits off the highest 25% of data from the remaining 75%) of these national distributions. As such, NDRLs are not optimum doses, but nevertheless they are helpful in identifying potentially unusual practice (healthcare facilities where median doses are among the highest 25% of the national dose distribution). DRLs can be also established for a region within the country or, in some cases, regions of several countries.
They are not intended to be applied to individual patients and should not be used as dose limits. Instead, the DRL is an essential tool in the optimisation process, especially as dose limits are not relevant in the medical exposure of patients. In surveys performed to acquire dose information for different procedures, it is important to identify radiation doses that are too low as well as too high, as both may have consequences for the patient.
[7]

9. Developing DRL across Europe
DRL have been shown to reduce the overall radiation dose and the range of doses [8] however the ways DRL are being developed varies.
2014 data highlights that DRL for adult x-ray examinations have been established in 72% of the 36 European countries,
only 39% of the countries have established DRL for paediatric x-ray examinations [9].
For adult DRL, 77 % are based on national dose surveys in Europe while the rest are based on published values or recommendations
Similarly, 64 % of paediatric DRL are based on national dose surveys while the rest are based on published European guidelines or other publications [10].
-European Directive 2013/59/Euratom [11]
[8] International Commission on Radiological Protection. Diagnostic reference levels in medical imaging, draft report for consultation
[9] European Commission. Radiation protection Nº 180, medical radiation exposure of the European population, Part 1/2, Directorate-General for Energy, Directorate Nuclear Safety & Fuel Cycle Unit D3 d radiation protection
[10] European Commission (2014) Radiation Protection Nº 180, Medical Radiation Exposure of the European Population, Part 1/2, Directorate-General for Energy, Directorate D — Nuclear Safety & Fuel Cycle Unit D3 — Radiation Protection.
[11] European Directive 2013/59/Euratom, Basic Safety Standards

10. Aim and Objectives
The aim of the study was to identify any variation in radiographic practice across Europe when imaging commonly performed examinations of the chest, abdomen and pelvis using CR and DR.
Objectives to explore:
the range of imaging equipment currently used in hospitals
the standard operating parameters used across departments
levels of awareness and use of DRL in the different countries

11. Methodology
Ethical permission was sought and granted from Ulster University in Northern Ireland.
Online questionnaire survey designed via SURVEYMONKEY.
Survey was sent as a link embedded in an .
The questionnaire consisted of 46 questions in total with 28 open-ended questions allowing respondents to provide their own answers combined with 18 closed questions requiring specific information on the use of CR and DR

12. Questionnaire design Two parts. Characteristics of the department
-hospital type,
-radiography staff (number, EQF level and years of experience)
-x-ray equipment used (Film screen, CR or DR)
-staff awareness of the existence of local or national DRLs.
(ii) Acquisition parameters for the three common examinations i.e. PA chest, AP abdomen and AP pelvis
-kVp, mAs, Source to Image receptor distance (SID) or Focus to Film Distance (FFD), anti-scatter grid use.
(the questionnaire asked respondents to supply average exposure data specifically for average sized male patients between 65 kg and 75 kg in

13. A random selection of 50 % of countries (n=17) which were members of the European Federation of Radiographer Societies (EFRS) were selected from sealed envelopes. The educational institutions who are affiliate members of the EFRS were contacted via their contact details supplied online Each of these radiography educational institutes were asked to identify 3 radiographers in 3 different hospital networks (where possible) to complete a survey via SurveyMonkey. Cases of initial non-response were followed up by reminder s. Descriptive statistics were performed with the aid of Excel and SPSS version 21.
among a total of six radiographic staff in educational institutions in the UK, Ireland and the Netherlands
This included native and non-native English speakers, who would not be included in the target distribution group.
Following feedback from the pilot study, the questionnaire was revised to decrease ambiguity of questions for non-native English speakers and also decrease the length of time commitment required to complete the questionnaire.
A pilot study was performed to highlight any ambiguity in questions and test the validity and reliability of the questionnaire prior to use.
Inter-rater reliability was tested by inviting two staff members of the same institution
T respondents in the pilot study were then asked to complete the questionnaire again on a second occasion 3 weeks later to test–retest reliability.

14. Results
Completed questionnaires were returned from 12 out of the 17 different countries selected across Europe.
response rate of 70%
A total of 51 survey responses were sought and 28 completed survey responses were received from Austria, Belgium, Denmark, Estonia, Finland, Hungary, Ireland, Italy, Latvia, Malta, Netherlands, Sweden.
response rate of 55% from the individual hospitals in 12 countries across Europe.
Incomplete questionnaires were not included in data analyses.
Responding radiology departments were 51 % university hospitals, 41 % general hospitals and 8% were private hospitals.

15. Range of imaging equipment
4% of departments using CR alone
39% using DR solely
57% use both DR and CR together
Figure 3. Types of equipment in use

16. Standard operating parameters used
Exposure factors varied greatly for PA chests and AP abdomens using both
CR and DR digital systems however exposures for AP pelvis was more
comparable as illustrated in table 1
Table 1 Standard operating parameters used for chest, abdomen and pelvis radiography
Chest CR DR
Abdomen CR
Abdomen DR
Pelvis
kVp
mAs
SID (cm)
55-130
1-6
95-150
1-5
65-100
16-75
90-180
77-109
10-40
77-81
16-77
90-150
70-85
13-70

17. This variation was noted across all parameters including kVp, mAs, SID and also included variation in the use of anti-scatter grids. Anti-scatter grids were used for all chest radiography in both DR and CR, however when imaging the abdomen and pelvis anti-scatter grids were more commonly used for DR than CR.

18. Levels of awareness/adherence to DRL
-74 % of respondents stated that they were using nationally established DRL -13 % were using LDRL -13 % reported they do not use DRL
Figure 4. Awareness of DRL in imaging departments

19. Discussion DR equipment is more prevalent than CR or conventional film
Great variation in the standard operating parameters and practice across the three common examinations.
chest kVp - some departments favoured low kVp techniques and others high kVp techniques.
CR exposures for abdomens ranged from 65 kVp to 100 kVp
SID used for abdomen examinations with distances varying between 90 cms and 180 cms.
Corresponding variation in radiation doses among countries
Staff awareness of DRL needs to be increased to ensure DRL are adhered to both locally, nationally and internationally.
The majority of hospitals perform a high kVp technique for imaging the chest (85%).
This is important to note as Andria et al [13], identified that to obtain the best balance between image quality and dose to air, operators should use an average tube voltage value of 90 – 110 kV. Use of lower kVp settings may not fully optimise the sensitivity of the detector.
This variation will have a significant impact on the exposure parameters required to produce a diagnostic image, the type of grid used (if any), whether AEC can be utilised and the corresponding dose to the patient.
The majority of responding hospitals were large university hospitals who would be expected to keep up-to-date with, and conform to, European and International regulations governing radiological protection and the use of DRL. Although 20 % of the departments were relatively small, with less than 20 staff employed, the majority of departments employed more than 40 staff, reflecting the size of the departments and the potential workload that this implies. The use and awareness of DRL was encouraging, with 74 % of respondents using National DRL and a further 13 % using LDRL, this equated to 87 % using DRL. An additional 13 % of respondents were not aware of any DRLs in use.

20. Conclusions
Standardisation of protocols and exposure parameters to ensure that there is continued adherence to the ALARA principle.
Operators must have a good knowledge of all technical factors in relation to patient dose and image quality in digital radiography.
DRL should be revised in many hospitals in European countries to ensure they represent current national practices.

21. Recommendations
Smaller countries without DRL can compare their typical patient dose quantities in present practice to DRL already established in other countries. Selecting the most appropriate exposure factors at the time of x-ray exposure is the simplest and most effective way to ensure adherence to the As Low As Reasonably Achievable (ALARA) principle.

22. Acknowledgements
The Authors wish to thank the College of Radiographers Industry Partnership Scheme (CORIPS) Research Grant which enabled the completion of this project.

23. Thank you for listening.
Questions?