ACR Phantom Phantom Images

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

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)

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

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

BC Patient Dose - Head DRL

BC Patient Dose - Chest

BC Patient Dose – Abdomen

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

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

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

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

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

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

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

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

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

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

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”

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.

Acceptance testing Items for Acceptance Testing Film CR DR Radioscopic CT 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

Acceptance testing Items for Acceptance Testing Film CR DR Radioscopic CT 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)

Acceptance testing Items for Acceptance Testing Film CR DR Radioscopic CT 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

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

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?

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

Personnel Qualifications Responsible User X-ray equipment Operator RSO

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

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

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

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.

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

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

The only perfect science The Future The only perfect science is hindsight