Reference Values in Diagnostic Radiology Application and Impact
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Transcript of Reference Values in Diagnostic Radiology Application and Impact
SENTINEL(SAFETY AND EFFICACY FOR NEW TECHNIQUES AND
IMAGING USING NEW EQUIPMENT TO SUPPORT
EUROPEAN LEGISLATION )
22 Partners 17 member states3 accession states
Background EU
• Health care equates to 8.4% of GDP
• Radiology is 10% of revenue expenditure
• Radiology equipment is 15% of capital expenditure
• In the UK this equates to 15,000,000,000 euros
Background SENTINELEuropean Union
• Population 457,000,000• 180,000,000 radiology
examinations per year• Population exposure 220,000
man Sv
BackgroundSENTINEL
• 90% of all patient examinations• 60% of collective dose• 50% of man-made sources of
radiation
BackgroundSENTINEL EU CA
• Public concern about radiation in general
• Public want safe X-ray examinations
• Are all examinations justified
Technology Driven Revolution in Radiology
Introduction of new technology (computing) and imaging devices (digital) in radiology and nuclear medicine. These must be safe
Main Objectives SENTINEL
• Address efficacy and safety issues in all digital diagnostic examinations and nuclear medicine
• Particular emphasis on high dose procedures and sensitive groups
Objectives SENTINEL
• Establish physical and clinical image quality criteria and link the two
• Establish reference levels for new procedures, particularly for interventional radiology and cardiology
Objectives SENTINEL
• Develop good practice guidelines for new digital imaging equipment and procedures
• Develop training courses and supporting material
• Identify ethical concerns
Functional Performance and Standards
• Investigate image quality indices and referral criteria
• Equipment performance surveys• IEC/CEN/CENELEC
Efficacy and SafetyCardiology and Interventional
Radiology
• Develop functional performance standards• Patient dose surveys• Optimisation studies• Use of DICOM (digital imaging and communications in
medicine) header for surveys and QA
DICOM Header
• DICOM header contains informationon the procedure and dosimetry
• Accurate dosimetry requires extra calculations and calibration.
• Important differences between thedifferent modalities and different X-ray systems.
Use of DICOMHeader
• On-line patient dosimetry requires significant interaction with the industry to clarify the data containedin the header
• Transfer of this information to data bases still not fully solved
• Dosimetry survey performed by a PClinked to the hospital RIS/PACSsystem
• IEC developing a dosimetry standard following SENTINEL request
DICOM HEADER(contains useful
information for QA, audit and patient
dosimetry)Siemens Axiom FD important DICOM tags(0018,0040) : Cine Rate : 30(0018,0060) : KVP : 97(0018,1030) : Protocol Name : Reg(0018,1110) : Distance Source to Detector : 947(0018,1111) : Distance Source to Patient : 798(0018,1150) : Exposure Time : 786(0018,1151) : X-ray Tube Current : 271(0018,1154) : Average Pulse Width : 6.5(0018,115E) : Image Area Dose Product : 1839(0018,1162) : Intensifier Size : 160(0018,1190) : Focal Spot(s) : 0.4(0018,1510) : Positioner Primary Angle : 0(0018,1511) : Positioner Secondary Angle : 0(0018,1702) : Collimator Left Vertical Edge : 0(0018,1704) : Collimator Right Vertical Edge: 1023(0018,1706) : Collimator Upper Horizontal Ed: 0(0018,1708) : Collimator Lower Horizontal Ed: 1023
Computed radiography (CR) Digital radiography with flat detector (DR)
Relevant DICOM tags GE Chest flat panel(0008,0020) : Study Date : 27/01/03(0008,0030) : Study Time : 10:31:12(0008,0033) : Image Time : 10:32:43(0008,0068) : Presentation Intent Type : FOR PRESENTATION(0008,103E) : Series Description : TORAX(0010,0020) : Patient ID : 795607(0010,0040) : Patient's Sex : F(0010,1010) : Patient's Age : 085Y(0018,0015) : Body Part Examined : (0018,0060) : KVP : 125(0018,1150) : Exposure Time : 5(0018,1151) : X-ray Tube Current : 250(0018,1153) : Exposure in uAs : 1400(0018,115E) : Image Area Dose Product : 0.83557(0018,1190) : Focal Spot(s) : 0.6(0018,1405) : Relative X-ray Exposure : 61(0018,7060) : Exposure Control Mode : AUTOMATIC(0018,7062) : Exposure Control Mode Descript: AEC_left_and_right_cells(0028,0010) : Rows : 2022(0028,0011) : Columns : 2022(0028,0100) : Bits Allocated : 16(0028,0101) : Bits Stored : 14
(0008,0020) : Study Date : 04/12/2003(0008,0022) : Acquisition Date : 04/12/2003(0008,0060) : Modality : CR(0008,0070) : Manufacturer : AGFA
(0008,0080) : Institution Name : HCSC(0008,1010) : Station Name : ADCC2
(0008,103E) : Series Description : lumbar AP(0010,1010) : Patient's Age : 020Y(0018,0015) : Body Part Examined : LSPINE(0018,1004) : Plate ID : U13-35
(0018,1401) : Acquisition Device Processing : 60025Ia712Ra(0018,1403) : Cassette Size : 35CMX43CM(0018,1404) : Exposures on Plate : 342
(0018,5101) : View Position : AP(0018,6000) : Sensitivity : 4.00000000E+02(0019,1010) : Image processing parameters : MENU=60025 CC=0 MC=3.00 EC=0.00 LR=2.00 NR=4.00(0019,1013) : Sensitometry name : NK5
(0019,1015) : Dose monitoring list : 1.54(0020,0013) : Image Number : 1(0020,1002) : Images in Acquisition : 1(0028,0010) : Rows : 3730(0028,0011) : Columns : 3062(0028,0100) : Bits Allocated : 16(0028,0101) : Bits Stored : 12(0028,0102) : High Bit : 11
2. DICOM header information is
extracted
1. Images are
received4. ALARMS are
displayed3. COMPARISON with reference
values
What Parameters are audited
• Patient entrance dose (entrance air kerma).
• Dose area product (collimation).• Radiographic technique (e.g. appropriate
kVp).• Appropriate use of the AEC.
What Parameters are audited
• Flat panel detector temperature.• Number of series, number of images per
series, kV, mA, ms and total number of images per procedure.
• Exposure index and post-processing parameters (for CR).
• Repeated images (retakes).• Image quality (basic evaluation).
A total of 3,506 paediatric patients have been selected for the dose evaluations
0 <1 years sample size
1 < 5 years sample size
10 < 15 years sample size
Chest without bucky 1180 309 92
Chest with bucky 0 181 363
Abdomen 93 30 150Pelvis 254 128 137
TOTAL sample5 <10 years sample size
69122
1724
799342641
143
255
Standardisation
• Direct Input to Industry both through Representation and as working participants in Standardisation Bodies
• Brings research results directly to bear on Equipment Design Process and Industry thinking
Formal Collaboration with IEC
• Acceptance Testing/Commissioning/QA• Long term differences and lack of trust
between industry engineers, end user physicists, et al.
• Criteria for Acceptability of Equipment in Europe under MED
• Major Achievement: Meeting (Oct 2007) between SENTINEL and IEC Industry representatives agreed to work approach and common issues
Efficacy and Safety in Mammography Screening
• Digital mammography• Risk/benefit studies• Tissue sampling techniques
Efficacy and Safety in Mammography Screening
Efficacy and Safety in Mammography Screening
Defining Aspects of Radiation Protection
• Relatively strong science base• Developed mainly outside medicine, but is
used mainly within medicine• Employs arcane impenetrable language
invented and protected by Physicists• Inept in Social and Political Sciences (Note
EU Medico Legal Survey)• Global Industry and Local Health Care
Provision
Ethics Issues in Radiology
• Identified a problem for Radiation Protection arising from a shift in dominant values in society since ICRP 26 and 60
• Ethicists will not solve the problems for us, but help us identify and formulate them
• Training essential to produce ethically sensitive and competent professions. Presently weak in this area.
Examples of Areas
• Right to Life• Right to Bodily Integrity• Individual Choice• Consent• Equality• Equity• Special Needs• Ageism• Trust of Authority• Trust in Professions
Some Issues Identified
• Major Issues around Justification• Philosophical assumptions underlying ICRP
Recommendations need re-examining• Pregnancy Issues• Medico Legal Issues• Population Screening Issues• Issues around consent, authorisation, power
of attorney, personal choice, self referral etc.• Non Transparent Language for Discourse,
particularly Quantities and Units
Pregnancy
• Basis for Recommendations• Diversity of Practice throughout
Community• Widespread high dose
procedures need a more consistent approach
• Patient Consent?
Non Medical Exposures
• Exposures not primarily MEDICAL; Common Feature is lack of Medical Indication. Include:• Medico Legal, • Security, • Evidential• Commercial health screening, • Art
Training Guidelines
• Training needs identified• Training syllabus developed• Dissemination to member states
via a series of training courses
Summary
• Safer, more effective procedures and examinations using new technology
• Greater public acceptance of medical uses of radiation
• Safer, more cost effective health care
Radiology Can Be Decorative!
---- Or
Threatening
Is It Ethical ?
Is It Safe ?Is It Justified ?