Imaging Technology for

Non Medical Human Imaging

Geraldine O’Reilly

IAEA Technical Meeting on Implementation of the Requirements of the International Basic Safety Standards in

relation to Non-Medical Imaging

17th – 20th January 2017

Non Medical Human Imaging

Human imaging using radiation for purposes other than

medical diagnosis, medical treatment or biomedical research

Assessment of fitness for employment

Assessment of physiological suitability for a career or sport

Assessment of athletes before a selection or transfer

Determination of age for legal purposes

Obtaining evidence for legal purposes

Detection of drugs concealed within the body

Immigration or emigration requirements

Pre-insurance checks

Obtaining evidence for a compensation claim

Human Imaging Using Radiation performed by Medical Personnel and Medical Radiological Equipment

[3.61 International BSS GSR Part 3]

Procedures with inspection imaging devices in which radiation is used to expose persons for the purpose of detection of

concealed weapons,

contraband

or other objects on or within the body

NB : - Public Dose Limits apply

- Possibility of alternative techniques to be offered if available

Inspection Imaging Devices Used to Expose Persons

Human Imaging Using Radiation

Performed by Medical Personnel

and Medical Radiological Equipment

Imaging Modalities General X-ray

CT Ultrasound MR

Intra-oral OPG

General Radiography System

X-ray tube installed on overhead rails for flexible positioning

Chest detector / wallstand

General Radiography - Imaging Process X-rays passing through body are absorbed to different degrees. This results in

differential attentuation which can be captured by an image detector.

X-ray production

Beam Shaping / collimation anatomy

X-ray detection Differential

Attenuation / Latent image

Image formation

General Radiography System Projection radiography 2D; superimposition of overlying

structures Static images Anatomical information Film/screen or digital image

receptors High spatial resolution Typical doses .0005 to 0.7mSv Can be used for chest x-rays,

extremeties, abdomen, pelvis etc

Tilting wallstand detector for extremity examinations

General Radiography System – Applications

Assessment of fitness for employment

Assessment of physiological suitability for a career or sport

Assessment of athletes before a selection or transfer

Determination of age for legal purposes

Obtaining evidence for legal purposes

Detection of drugs concealed within the body

Immigration or emigration requirements

Pre-insurance checks

Obtaining evidence for a compensation claim

Upper and lower abdominal plain films showing multiple cocaine filled packets distributed throughout the colon Pinto et al. BJR (2016) 89

Assessment of skeletal maturation is done by assessing the ossification and maturation of the epiphysis of the hands and wrists and comparing them with standards For example in the Greulich and Pyle method, the radiograph of the whole hand and wrist is compared with images in the Atlas. Sharma K . Homeopathic Journal (2008) 1, 5

X ray for emigration or immigration requirements Conventional chest radiograph may be sufficient for diagnosis of TB in the appropriate clinical setting

X-ray tube

Patient

Screen-film Cassette

X-ray film

General Radiography - Image Detector Types

Computed Radiography

Storage phosphor plate

Integrated digital detector

X-r

ay d

ete

ction

PA

CS

Arc

hiv

e

Digital image

Digital image

CT Imaging Computed Tomography

Technique used to obtain cross sectional images

through body.

Overcomes overlapping structures found in plain

projection radiography.

Resultant images represent 2D slices through the 3D

body.

Very good contrast resolution

High dose modality

Scout view 2D slice

CT System – Applications

Assessment of fitness for employment

Assessment of physiological suitability for a career or sport

Assessment of athletes before a selection or transfer

Determination of age for legal purposes Obtaining evidence for legal purposes

Detection of drugs concealed within the body Immigration or emigration requirements

Pre-insurance checks

Obtaining evidence for a compensation claim

Basic Construction & Operation of CT Scanner

• Patient is positioned in beam on motorised table

• X-ray tube and detectors

rotate around patient gathering X-ray projections

• X-ray projections are

mathematically reconstructed to form cross

sectional images

X-ray of the lower abdomen shown alongside a topogram or scout view of a subsequent CT

same pattern seen on each

Oblique coronal and oblique axial reformatting of the CT scan showing multiple packets in the colon again, with difference in density suggesting difference in purity of content.

Pinto et al. BJR (2016) 89

Plain Film and CT Images of Multiple Cocaine Filled Packets

CT Imaging of the clavicle has been used to assess age

Relative timing of epiphysis development and its union with clavicular shaft can be used in age estimation

CT imaging allows visualisation of the target area without the superimposition of other bones

Stage can be correlated to age range if appropriate reference data available

Not a definitive method of age assessment Additional tools required - dental , hand x-

rays, physical and psychological assessment

Age Determination using CT Imaging

A.Doaa et al. Int.J.Morphol., 33(4):1419-1426, 2015

Stages (1-5) of union of medial clavicular epiphyses

Dental Radiology

Orthopantomogram

X-ray tube

Detector

Intra-oral

Panoramic Radiography

Orthopantomogram

Tooth development used to estimate dental age

Method of Demirjian et al (1973) is one of those used

Standard tables of tooth development available based on surveys

For any tooth and stage of development, there will be a range reflecting normal variation

Low associated dose of radiation Use of method relies on having

appropriate reference group Limitations in reliability of method

and should as part of holistic approach

Serious concerns about use of this methodology particularly for older adolescents and young adults

Examination Mean effective dose (mSv)

Risk of fatal cancer

Approx equivalent period of natural background radiation*

Extremity X-ray (Knee, Foot, Hand)

0.0005mSv ~ 1 in 40 million 1 hour

Intra-oral Dental X-ray 0.005mSv 1 in 4 million 0.5 day

OPG 0.014mSv

Chest X-ray 0.02mSv 1 in 1 million 2 days

Abdomen 0.7mSv 1 in 30,000 2 months

CT Chest 6mSv 1 in 3,000 1.5 years

CT Abdomen 10mSv 1 in 2,000 2.5 years

Typical Doses Associated with Medical Imaging Techniques

Background radiation (Ireland ) = ~4mSv per annum (0.011mSv per day)

Non-ionising Imaging Techniques MRI - Magnetic resonance

imaging uses radiofrequency waves and powerful magnetic fields to image Hydrogen content within tissue

Ultrasound uses high frequency sound waves to provide an acoustic map of internal structures and perform blood flow measurements.

No radiation exposure

associated with either technique

Many applications in diagnostic radiology; limited use for detection of drugs

Human Imaging Using Radiation Performed by Medical Personnel and Medical Radiological Equipment

NMIE are performed without clinical indication

A distinguishing feature is that in most cases the main reason for performing them does not relate to the health

of the individual

Person being scanned may not derive any benefit

Individual being scanned may even be disadvantaged

Contrasts sharply with practices within diagnostic radiology where practices are predicated on a risk benefit paradigm which assumes that benefit accrues to person exposed to risk

Where this is not the case, framework of RP, including justification, must be constructed so that exposed individual adequately protected

Justification and appropriate optimisation essential

Inspection Imaging Devices

Used to Expose Persons

September 11, 2001 ……….

– Led to increased focus on aviation security worldwide

– Range of enhanced measures introduced

– Screening of passengers & cargo

– Security of flight deck

– Pilot screening programmes

– …………………..

Inspection Imaging Devices Used to Expose Persons

Detection of concealed weapons, contraband or other objects on or within the body

Public Dose Limits apply

Back-scatter X-Ray scanners

Available Screening Technologies

Transmission X-Ray scanners

Millimeter wave scanners Passive Millimeter scanners

Transmission technique….

.03µSv per scan

Backscatter technique – radiation reflected from the subject and detected to form an image – shows concealed objects on the body – only reveals objects on body surface – dose typically <0.1µSv

– X-rays emitted by the equipment and pass through the body – concealed object observed on detected image – shows objects within the body – dose can be few µSv

X Ray Based Technologies

EXAMPLE DOSES

Dublin – Paris 5 µSV

Helsinki – Frankfurt 10 µSV

Frankfurt – Bangkok 30 µSV

London – Toronto 50 µSV

Amsterdam – Vancouver 70 µSV

Sea level:

0,03 µSv/h

0,2 – 0,3 mSv/a

Altitude km

In flight Radiation Doses D

ose

Rat

e, µ

SV/h

Transmission scanner dose Backscatter scanner dose

David Brenner. Radiolgy 2011 ; 259:6-10

David Schauer. Radiology 2011 ; 259:12-16

Backscatter Scanners

For most passengers, if you have constraints (0.25-0.5 mSv ) it is unlikely that these will be approached with

but

could potentially be exceeded by those persons who are scanned several times a day throughout the year (e.g. flight crew, ground staff, couriers)

Transmission Scanners

Scanning of frequent fliers with X-ray transmission scanners could result in both constraints and public dose limit being exceeded, assuming a dose of 4 microsievert per scan

Doses Associated with X ray Based Security Scanners

mm Wave Technology

– Passive and active systems

– Active systems use high frequency transmitters to irradiate target and measure reflected mm wave radiation

– Some systems use moving transmitter/receiver antenna arrays; passenger stands still inside cabinet

– Some systems use stationary arrays and passenger turns around in front of the system

mm Wave Scanners

Screens passengers for metallic and non-metallic weapons, standard and home-made explosives (sheet and bulk), liquids, gels, plastics, powders, metals, ceramics, and other objects

Quick stationary scan - 1.5 seconds

Processes 200 - 300 people per hour

Targeted search reduces need for pat-downs

Uses millimeter radio wave (MMW) technology

Automatic target detection technology ensures passenger privacy by highlighting threats and anomalies using a generic mannequin that resembles a human outline.

Eliminates the review of images as data is privately processed by software without human intervention to determine if any threats are present

And the future…...

Transport hubs in Los Angeles, Denver and Washington are soon to trial Total Recall-style high-speed body scanners

mm wave technology coupled with fast recognition algorithms

Scan takes a fraction of a second

Can detects weapons and explosives

800 persons per hour

Scanning hand luggage may be an issue

European Union Position

September 2008 - 2011 – Aviation security experts within EU prompted European

Council & Parliament to allow security scanners for screening persons – Concerns surrounding impact on human rights, privacy, personal

dignity and data protection

– Council requested more in depth assessment

– Assessment concluded that security scanners effective and should be allowed with certain provisions

– Risks to human health to be avoided and fundamental rights protected

– Period of review and consultation followed…….

In 2011, European legislation was introduced allowing security scanners, subject to certain conditions:

– no storage, retention copying, printing or retrieval of images;

– unauthorised access or use of images prohibited and to be prevented;

– image reviewer to be in a separate location to the screened person and others.

– passengers to be informed about conditions under which the security scanner control takes place.

– only security scanners not using ionising radiation to be deployed

– passengers given the right to opt out and be subject to an alternative method of screening.

European Legal Requirements

Allowed methods – hand search;

– walk-through metal detection (WTMD) equipment;

– hand-held metal detection (HHMD) equipment;

– explosive detection dogs;

– explosive trace detection (ETD).

– security scanners which do not use ionising radiation

European Commission Advisory Group (SCENHIR) Opinion

No scientific basis to separately consider potentially vulnerable groups (e.g. pregnant women, children) in risk assessment for scanners using back scatter or for an occasional transmission scan

No sufficient scientific basis for

making a quantitative risk estimates such as calculating additional number of cancer cases induced by the introduction of security scanners at airports either to the general public or the exposed workers.

2011

Appropriate application of the framework of protection, including justification and optimisation, will provide protection for anyone exposed by the security screening system, including sensitive populations. Thus, if the recommendations in in this report are met it will not be necessary to take specific protection actions for the security screening of children or pregnant women

ICRP 125 (2014)

Guidance Documents & Reports

2014

Status Update – US currently deploys several hundred security scanners ; in last couple of

years, x-ray scanners replaced with millimetre wave technology

– Change to non ionising technology in US driven by privacy concerns

– Russia has been using security scanners at airports since 2008 and will continue to deploy them more widely in the future.

– Other countries also trialled and subsequently introduced security scanners (e.g. Canada, Australia)

– X-ray scanners trialled in Finland, UK, Netherlands, Switzerland

– Several Member States (e.g. Italy, France, Germany and Austria) prohibit the use of ionising radiation for non-medical purposes

– Japan trialled scanners at end 2015 in advance of 2020 Tokyo Olympics

– In the UK, where x ray scanners had been used, all security scanners must now use millimetre wave technology

Summary Imaging technology used for Non Medical Human Imaging in medical facilities

Risk benefit paradigm that is the norm for patients does not apply

Essential that an appropriate framework of RP established

Imaging protocols should be optimised for exam

Dose constraints should be established

Limitations of imaging in relation to age assessment should be understood

Concerns about use of security scanners relating to creation of body images and use of ionising radiation

European union has a list of approved methods/technologies for security screening; x-rays not included

No image storage, retention, copying, printing or retrieval

Appropriate management of non medical imaging exposures requires input from sources beyond the established radiation protection community

THANK YOU FOR YOUR ATTENTION