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 ?