1. ACR Phantom Phantom Images

2. Overview Session 2 CT 20 Patient dose 15 Questions 10
Equipment Purchase/ Acceptance Testing
Questions 10
Personnel qualifications
Education and training

3. Patient Dose (A 3.0)
It is recommended that Diagnostic Reference Levels (DRLs) be used as guidance in the optimization of patient dose
DRLs are values related to patient dose using Dose Indicators which can be easily measured
dose-linear product (DLP) for CT or
dose-are product (DAP) for radiography/radioscopy.
Conversion factors are available to convert from Dose Indicator values to Effective Dose (E)

4. Diagnostic Reference Levels
It is very difficult to ‘optimize’ patient dose
However, it is relatively easy to decide those doses which are clearly too high and unacceptable
DRLs are derived from large surveys of examinations in a region or country; usually the DRL is set at the 75% level of the distribution

5. BC CT Dose Survey 2004
Hospitals around BC were asked to provide data on routine head, chest, abdomen, pelvis CT
Data collected from 18 hospitals

6. BC Patient Dose - Head
DRL

7. BC Patient Dose - Chest

8. BC Patient Dose – Abdomen

9. Reference Doses BC * 75 percentile Exam Reference DLP Reference Dose
mSv
mGy.cm 
Head
1300 3
Chest
600
10.2
Abdomen
900
13.8
Pelvis
650
12.3
Abdomen-Pelvis
1100
18.7
* 75 percentile

10. Reference Doses
For other imaging systems the dose-area product (DAP) is the most convenient to use to evaluate patient dose
Should be a requirement on all new radiographic and radioscopic systems

11. Dose Area Product Meter
Collimator
X-ray field
Dose Area Product detector after collimator intercepts all radiation used both for radiography and radioscopy
X-ray Tube
5.2 Gy.cm2
PACS
DAP meter

12. Patient Dose Monitoring
It is now technically possible to estimate patient dose from most x-ray systems
Equipment
Dose Indicator
Status CT
Dose-length product DLP
Available on all CTs
Radiographic/
Fluoroscopic/
Angiographic
Dose-area product DAP
Available on all new units- can be retrofitted CR
Exposure Index (EI) of detector
All CR
Both DLP and DAP values are directly related to patient dose

13. CT Patient Dose Monitoring
Patient ID:
Exam No:
Exam Description: CABD2PCT
Date:
Dose Report
Series
Type
Scan Range
(mm)
CTDIvol
(mGy)
DLP
(mGy.cm)
Phantom cm 1
Scout - 2
Helical
S111-I319
12.77
577.08
Body 32
1/1

14. Diagnostic Reference Levels
Radiographic  
Exam
  View
DRL 
Generalized Conversion Coefficients DAP to Effective Dose
Gy.cm2
mSv per Gy.cm2
Skull PA 2
0.03
Lat
1.3
Chest
0.15
0.12
0.6
0.1
T Spine 7 AP 4
0.2
L Spine 11 5
Abdomen
Pelvis
0.3

15. Diagnostic Reference Levels
Complete
 Exams
DRL
DAP to E
Fluoroscopy
Time
Gy.cm2
mSv per Gy.cm2
minutes
Barium Swallow 9
0.26
2.3
Barium Meal 14
2.7
Ba follow thru 12
2.2
Barium enema 24
2.8
IVP
0.2
MCU
1.9
Nephrostography
4.8
Retro Pyelogram 13 3
T tube cholangiogram 8
Sinography
2.1
Small bowel enema 40
9.2
Venography leg 7
Coronary angiography 29
4.5

16. Diagnostic Reference Levels
 Complete Exam
DRL
DAP to E
Fluoroscopy
Time
Gy.cm2
 mSv per Gy.cm2
minutes
Biliary Drainage 50
0.26 15
Facet joint injection 5
0.2
1.8
Hickman line 3
0.1
1.4
Nephrostomy 14
0.16
5.1
Esophageal stent 25
5.9
Esophageal dilation 11
2.8
Pacemaker
8.2
PTCA single stent 26

17. Diagnostic Reference Levels
Exam
EU DRL
Dose Area Product
Gy cm2
VGH DR
Ave Dose Area Product
DAP to E Conversion Factor
mSv/Gy cm2
Skull AP 4
0.2
0.03
Chest PA
0.15
0.12
Abdomen AP 7
2.3
Pelvis AP 5
1.4
Barium enema 30
IVP 14
0.1
Coronary Angiography
35-75
120*
*diagnostic + angioplasty

18. Overview Session 2 CT 20 Patient dose 15 Questions 10
Equipment Purchase/ Acceptance Testing
Questions 10
Personnel qualifications
Education and training

19. Acceptance Testing (C 1.0)
“The following steps must be included for the establishment of QC procedures
Clear performance specifications
Baseline performance
Reference images
QC Action Levels”

20. Baseline value determination Next constancy testing
Quality Control
Baseline value determination
Device use period
Next constancy testing
Data evaluation
Within the
established criteria
Remedy
Acceptance testing
FAIL
PASS
Acceptance testing
New equipment
Conformance to manufacturer’s specifications/RFP
Baseline performance
There is a distinction between acceptance testing and regularly performed QC. Acceptance testing is performed to verify the manufacturers claims and to verify compliance with regulatory standards. Constancy tests are performed to determine whether the performance of a device has changed after its installation/acceptance. More specifically, a certain test is conducted at appropriate intervals to check the deviation of the current performance value from the reference performance value (baseline value).
If the measured performance value is within the predetermined acceptance deviation limit (established criteria), the device will be continuously used until the next test.
If the measured performance value is outside the acceptable range, an appropriate remedial action must be taken.

21. Acceptance testing Items for Acceptance Testing Film CR DR RadioscopicCT
1.0 Identification
1.1 Initial Inspection and Inventory X
1.2 Inspection of Documentation
2.0 Visual and Functional Tests
2.1 Mechanical Properties
2.2 Safety Systems

22. Acceptance testing Items for Acceptance Testing Film CR DR RadioscopicCT
3.0 Performance Evaluation (X-ray Generator)
3.1 X-ray Tube Voltage X
3.2 Current Time Product
3.3 Loading Time
3.4 Radioscopic Timer and Chronometer
3.5 Beam Limitation and Indication
3.6 X-ray Beam Filtration
3.7 Automatic Exposure Control
3.8 Automatic Intensity Control
3.9 Radiation Output
3.10 Maximum Air Kerma Rate
3.11 Phantom (Entrance) Dose (Rate)

23. Acceptance testing Items for Acceptance Testing Film CR DR RadioscopicCT
4.0 Performance Evaluation (Image Receptor)
4.1 Exposure Index X
4.2 Dynamic Range
4.3 Spatial Resolution
4.4 Contrast Detectability
4.5 Uniformity
4.6 Artifacts
4.7 Digital Detector Residual Image
4.8 Noise
4.9 Modulation Transfer Function
4.10 Mean CT Numbers (calibration and linearity)
4.11 Tomographic Section Thickness
4.12 Axial Patient Positioning Accuracy
4.13 Positioning of Patient Support

24. This new Code has implications for new equipment
Equipment Purchase
This new Code has implications for new equipment
Code 20A was usually a condition for RFPs
With Code 35 much more is involved
Performance of the x-ray system
At acceptance
In routine operation
Performance of the image receptor
Ability to determine patient dose indicators
At control
For transfer to PACS

25. Equipment Purchase Will service contracts cover the increased testing?
For new units
For existing equipment
At the moment radiation doses such as CTDI are not measured by any of the companies as part of QC
What about equipment not on service contract?

26. Overview Session 2 CT 20 Patient dose 15 Questions
Equipment Purchase/ Acceptance Testing
Questions
Personnel qualifications
Education and training 10

27. Personnel Qualifications
Responsible User
X-ray equipment Operator
RSO

28. Responsible User
Possess qualifications required by applicable province or statute eg RCPSC, CAMRT
Acquire refresher training according to similar standard
Ensure equipment functions correctly
Ensure equipment is used correctly
Establish safe operating procedures
Promulgate radiation safety for staff
Ensure radiation levels are within regulatory limits

29. X-ray Equipment Operator
Possess qualifications required by applicable province or statute eg RCPSC, CAMRT
Acquire refresher training according to similar standard
Have documented training
Ensure equipment is used correctly
Establish safe operating procedures
Promulgate radiation safety for staff
Ensure radiation levels are within regulatory limits

30. Overview Session 2 CT 20 15 Patient dose Questions
Equipment Purchase/ Acceptance Testing 15
Patient dose
Questions
Personnel qualifications
Education and training 10

31. Education and Training - Standards
Collation of Standards/Action Levels
Although frequency of tests is well covered in SC 35 not all Action Levels are defined.

32. Education and Training - QC
PACS and image display systems QC
Visual
Measurements
Image receptor quality tests and calibration CR DR DF CT

33. Education and Training - Dose
Patient dose measurement
Dose- area product (DAP) in radiography and radioscopy. Calibration of meters.
CTDI in computed tomography

34. The only perfect science
The Future
The only perfect science
is hindsight