RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY

1
RADIATION PROTECTION INDIAGNOSTIC
ANDINTERVENTIONAL RADIOLOGY
IAEA Training Material on Radiation Protection in
Diagnostic and Interventional Radiology

• L 21 Optimization of Protection in Pediatric
  Radiology

2
Introduction

• Good radiation protection policy in Pediatric
  radiology is essential.
• There exist International recommendations and
  code of good practice in this field which
  constitute a framework for an effective
  implementation of the optimization principle to
  diagnostic examinations.

3
Topics

• General recommendations
• Quality criteria for radiographic images
  (EUR-16261 document)
• Recommendations for X Ray equipment and rooms for
  pediatric radiology
• References

4
Overview

• To become familiar with the principles of
  radiation protection in pediatric radiology, the
  X Ray systems to be used and the principles of
  optimization and quality assurance.

5
Part 21 Optimization of Protection in Pediatric
Radiology
IAEA Training Material on Radiation Protection in
Diagnostic and Interventional Radiology

• Topic 1 General recommendations for pediatric
  radiology

6
General recommendations for pediatric radiology

• General, equipment and installation
  considerations
• The generator should have enough power to allow
  short exposure times (3 milliseconds) and the
  timer should allow short exposure times
• The generator should be of high frequency to
  improve the accuracy and reproducibility of
  exposures
• Automatic exposure control (AEC) devices should
  be used with caution in pediatrics
• AEC should have specific technical requirements
  for pediatrics

7
General recommendations for pediatric radiology

• Careful manual selection of exposure factors
  usually results in lower doses
• X Ray rooms for pediatrics should be designed for
  improving the childs cooperation (control panel
  with easy patient visibility and contact, etc.)
• Fast film-screen combinations have advantages
  (reduction of dose) and limitations (higher
  repetition rate)
• Low-absorbing materials in cassettes, tables,
  etc. Are specially important in pediatrics
  radiology

8
General recommendations for pediatric radiology

• The antiscatter grid in pediatrics gives limited
  improvement in image quality and increases
  patient dose given the smaller irradiated volume
  (and mass) the scattered radiation is less
• Antiscatter grids for pediatrics should have
  specific technical requirements
• Antiscatter grid should be removable in pediatric
  equipment, particularly fluoroscopic systems
• Image intensifiers should have high conversion
  factors for reducing patient dose in fluoroscopic
  systems

9
General recommendations for pediatric radiology

• Specific kV-mA dose rate curves for automatic
  brightness control (ABC) should be used in
  fluoroscopic systems for pediatrics.
• It is preferable not to use the ABC unless there
  is an automatic cut-off device.
• For CT examinations, the use of specific
  technical radiographic parameters for CT
  examinations should be promoted (lower mAs than
  for adults, and lower kV in some cases).
• The use of mobile X Ray units in pediatrics could
  raise special problems (low power, etc).

10
General recommendations for pediatric radiology

• In pediatrics, there are advantages and
  disadvantages of under-couch and over-couch
  fluoroscopy units
• Pulsed fluoroscopy allows patient dose reduction
• Digital equipment and the role/use of frame-grab
  technique may allow dose reductions
• The cine playback (digital) and video playback
  (digital/conventional fluoroscopy) in screening
  examinations may allow patient dose reductions
• Additional tube filtration may allow dose
  reductions

11
General recommendations for pediatric radiology

• Reduction of exposure
• The causes of repeating films in pediatrics
  should be analyzed periodically (reject analysis)
  as part of the audit program. Feedback should be
  foreseen
• Immobilization can reduce the repeating film rate
• The different immobilization devices available
  for pediatric radiology to make application
  atraumatic should be considered. The role of
  simple aids such as sticky tape, sponge wedges
  and sand bags should also be considered.

12
General recommendations for pediatric radiology

• Short exposure times can improve image quality
  and reduce the number of films repeated
• The use of mobile X Ray units for pediatrics
  should be restricted due to the difficulty in
  getting short exposure times
• Radiographers should have specific training in
  pediatric radiology
• Gonadal protection is specially important in
  pediatric radiology. Several sizes and types of
  protectors should be available

13
General recommendations for pediatric radiology

• Collimation is important (in addition to the
  basic collimation corresponding to the film size)
  in pediatric patients, particularly window
  protection for hips and lateral collimation
  devices for follow-up scoliosis
• The correct patient positioning and collimation
  is important in pediatrics, particularly for
  excluding the gonads from the direct beam
• It is important to establish whether adolescent
  girls (over 12 years) might be pregnant when
  abdominal examinations are contemplated

14
General recommendations for pediatric radiology

• Motion is a greater problem in children and could
  require specific adjustment of radiographic
  techniques
• Proper consultative relationship between the
  referring physician and the radiologist is
  specially important in pediatrics
• Agreed protocols and diagnostic pathways should
  be promoted

15
General recommendations for pediatric radiology

• Some radiological examinations are of
  questionable value in children (like some
  follow-up chest radiographs in simple pneumonia,
  abdominal radiographs in suspected constipation,
  etc.)
• The repetition of a radiological examination in
  pediatrics should always be decided by the
  radiologist.

16
General recommendations for pediatric radiology

• Appropriate projections for minimizing dose in
  high risk tissues should be used (PA projections
  should replace AP where possible for spinal
  examinations)
• Additional filters should be available to enable
  them to be easily changed (1 mm Al 0.1 and 0.2
  mm Cu should be available).

17
General recommendations for pediatric radiology

• Dedicated pediatric room or complete sessions
  dedicated to pediatric radiology should be
  available
• Experienced staff who can obtain the childs
  confidence and cooperation in a secure and
  child-friendly environment are of paramount
  importance in reducing radiation doses in
  pediatrics
• Specific referral criteria for pediatric
  radiology should be available, e.g. for head
  injury where the incidence of injury is low

18
General recommendations for pediatric radiology

• Referral criteria for all X Ray examination of
  children should be established, especially those
  which may be age-related, e.g. scaphoid not
  ossified, below age of 6 years, nasal bones
  cartilaginous below age of 3 years
• High kV techniques should be used when possible
• Long focus patient distances could be used to
  minimize patient entrance dose (with the
  compromise of appropriate exposure times)

19
General recommendations for pediatric radiology

• Light beam diaphragm to move the patient into
  position should be used rather than screening
  during overcouch fluoroscopy procedures
• Audit and quality assurance should be promoted in
  maintaining or improving image quality with
  reasonable dose

20
General recommendations for pediatric radiology

• Risk factors
• As children are at greater risk of incurring
  stochastic effects, pediatric examinations should
  require special consideration in the
  justification process
• Thus the benefit of some high dose examinations
  (e.g. computed tomography, IVU, etc.) should be
  carefully weighed against the increased risk

21
General recommendations for pediatric radiology

• Risk factors
• Longer life expectancy in children means a
  greater potential for manifestation of possible
  harmful effects of radiation
• Radiation doses used to examine young children
  should generally be smaller than those employed
  in adults
• Risk factors for cancer induction in children is
  between 2 and 3 times higher than for adults

22
General recommendations for pediatric radiology

• Patient dosimetry - Guidance levels
• Measuring patient doses in pediatrics presents
  special difficulties (small values)
• Dosimetric techniques used for patient dosimetry
  in pediatrics should be specifically adapted
• Patient dose values are related to patient size

23
General recommendations for pediatric radiology

• Guidance levels in pediatrics should be related
  with patient size
• Guidance levels available at present for
  pediatrics are limited of a small set of values
• The use of guidance levels in pediatric radiology
  should be used with caution due to the difficulty
  of measuring patient dose and the limited set of
  available values to be used as reference

24
General recommendations for pediatric radiology

• Protection of personnel and parents
• Parents can cooperate in the radiological
  examination of their children if they are duly
  informed and duly protected
• Parents exposure in this situation can be
  considered as a medical exposure but optimization
  criteria must be applied

25
General recommendations for pediatric radiology

• Parents or helpers should be duly informed and
  should know exactly what is required of them
• Pregnant women should not be allowed to help
  during pediatric examinations
• Lead aprons and lead gloves (if the hands are
  near the direct radiation field) should be used
  in these situations

26
ICRP-ISR smart message for pediatrics
27
Part 21 Optimization of protection in Pediatric
Radiology
IAEA Training Material on Radiation Protection in
Diagnostic and Interventional Radiology

• Topic 2 Quality criteria for radiographic images
  (EUR document)

28
European Guidelines on Quality Criteria for
Diagnostic Radiographic Images in Paediatrics,
July 1996. EUR 16261 EN Free PDF version
available at http//www.cordis.lu/fp5-euratom/sr
c/lib_docs.htm
29
(No Transcript)
30
(No Transcript)
31
Criteria related to images

• The Image Criteria for pediatric patients
  presented for a particular type of radiograph are
  those deemed necessary to produce an image of
  standard quality
• No attempt has been made to define acceptability
  for particular clinical indications
• The image criteria allow an immediate evaluation
  of the image quality of the respective
  radiograph. They are appropriate for the most
  frequent requirements of radiographic imaging of
  pediatric patients

32
Criteria related to images

• The anatomical features and body proportions vary
  due to the developmental process in infancy,
  childhood and adolescence
• They are different in the respective age groups
  and are distinct from those of a mature patient
• The Guidelines presuppose knowledge of the
  changing radiographic anatomy of the developing
  child.
• The term consistent with age indicates that the
  respective image criteria essentially depend on
  the age of the patient

33
Criteria related to images

• The smaller body size
• The age dependent body composition
• The lack of co-operation and many functional
  differences (e.g. higher heart rate, faster
  respiration, inability to stop breathing on
  command, increased intestinal gas etc.)
• Prevent the production of radiographic images in
  pediatric patients to which standard adult image
  criteria can be applied

34
Criteria related to images

• Correct positioning of pediatric patients may be
  much more difficult than in co-operative adult
  patients
• Effective immobilization often necessitates the
  use of auxiliary devices
• Sufficient skill and experience of the imaging
  staff and ample time for the particular
  investigation are the imperative prerequisites to
  fulfil this quality criterion in infants and
  younger children

35
Criteria related to images

• Incorrect positioning is the most frequent cause
  of inadequate image quality in pediatric
  radiographs
• Image criteria for the assessment of adequate
  positioning (symmetry and absence of tilting etc)
  are much more important in pediatric imaging than
  in adults
• A lower level of image quality than in adults may
  be acceptable for certain clinical indications

36
Criteria related to images

• An inferior image quality, however, cannot be
  justified unless this has been intentionally
  designed and must then be associated with a lower
  radiation dose
• The fact that the X Ray was taken from a
  non-cooperative pediatric patient (anxious,
  crying, heavily resisting) is not an excuse for
  producing an inferior quality film which is often
  associated with an excessive dose

37
Criteria for Radiation Dose to the Patient

• Expressed in terms of a reference value for the
  entrance surface dose for a standard sized
  pediatric patient
• Reference dose values are available only for the
  most frequently performed types of radiographs
  for which sufficient data were acquired in a
  series of European Trials on infants, 5 year old
  and 10 year old patients

38
Criteria for Radiation Dose to the Patient

• The assessment of compliance with the criteria
  for radiation dose to the patient for a specific
  radiograph unavoidably involves some form of dose
  measurement
• This requires representative sampling of the
  patient population
• A number of dose measurements methods are
  described in the European Guideline

39
General principles associated with good imaging
performance

• Image Annotation
• The patient identification, the date of
  examination, positional markers and the name of
  the facility must be present and legible on the
  film
• These annotations should not obscure the
  diagnostically relevant regions of the radiograph
• An identification of the radiographers on the
  film would also be desirable

40
General principles associated with good imaging
performance

• Quality Control of X Ray Imaging Equipment
• Quality control programs should be instigated in
  every medical X Ray facility and should cover a
  selection of the most important physical and
  technical parameters associated with the types of
  X Ray examination being carried out
• Limiting values for these technical parameters
  and tolerances on the accuracy of their
  measurement should be required

41
General principles associated with good imaging
performance

• Low Attenuation Materials
• Recent developments in materials for cassettes,
  grids, tabletops and front plates of
  film-changers using carbon fiber and some new
  plastics enable significant reduction in patient
  doses
• This reduction is most significant in the
  radiographic-voltage range recommended in
  pediatric patients and may reach 40. Use of
  these materials should be encouraged

42
General principles associated with good imaging
performance

• Patient Positioning and Immobilization
• Patient positioning must be exact whether or not
  the patient co-operates.
• In infants, toddlers and younger children
  immobilization devices, properly applied, must
  ensure that
• the patient does not move
• the beam can be centered correctly
• the film is obtained in the proper projection
• accurate collimation limits the field size
  exclusively to the required area
• shielding of the remainder of the body is
  possible.

43
General principles associated with good imaging
performance

• Patient Positioning and Immobilization

44
General principles associated with good imaging
performance

• Patient Positioning and Immobilization

45
General principles associated with good imaging
performance

• Patient Positioning and Immobilization

46
General principles associated with good imaging
performance

• Patient Positioning and Immobilization

47
General principles associated with good imaging
performance

• Patient Positioning and Immobilization
• Immobilization devices must be easy to use, and
  their application atraumatic to the patient.
• Their usefulness should be explained to the
  accompanying parent(s).
• Radiological staff members should only hold a
  patient under exceptional circumstances
• Even in quite young children the time allocation
  for an examination must include the time to
  explain the procedure not only to the parents but
  also to the child

48
General principles associated with good imaging
performance

• Field Size and X Ray Beam Limitation
• Inappropriate field size is the most important
  fault in pediatric radiographic technique
• A field which is too small will immediately
  degrade the respective image criteria
• A field which is too large will not only impair
  image contrast and resolution by increasing the
  amount of scattered radiation but also, most
  importantly, result in unnecessary irradiation of
  the body outside the area of interest

49
General principles associated with good imaging
performance

• Field Size and X Ray Beam Limitation
• Correct beam limitation requires proper knowledge
  of the external anatomical landmarks by the
  technician
• These differ with the age of the patient
  according to the varying proportions of the
  developing body.
• In addition, the size of the field of interest
  depends much more on the nature of the underlying
  disease in infants and younger children than in
  adults

50
General principles associated with good imaging
performance

• Field Size and X Ray Beam Limitation
• A basic knowledge of pediatric pathology is
  required for radiographers and other technical
  assistants to ensure proper beam limitation in
  these age groups
• The acceptable minimal field size is set by the
  listed recognizable anatomical landmarks for
  specific examinations

51
General principles associated with good imaging
performance

• Field Size and X Ray Beam Limitation
• Beyond the neonatal period, the tolerance for
  maximal field size should be less than 2 cm
  greater than the minimal
• In the neonatal period, the tolerance level
  should be reduced to 1.0 cm at each edge

52
General principles associated with good imaging
performance

• Field Size and X Ray Beam Limitation
• In pediatric patients, evidence of the field
  limits should be apparent by clear rims of
  unexposed film
• Beam-limiting devices automatically adjusting the
  field to the full size of the cassette are
  inappropriate for pediatric patients
• Discrepancies between the radiation beam and the
  light beam must be avoided by regular assessment

53
General principles associated with good imaging
performance

• Additional filtration
• The soft part of the radiation spectrum which is
  absorbed in the patient is useless for the
  production of the radiographic image and
  contributes unnecessarily to the patient dose
• Part of it is eliminated by the filtration of the
  tube, tube housing, collimator etc., but this is
  insufficient
• Most tubes have a minimum filtration of 2.5 mm
  Al
• Additional filtration can further reduce
  unproductive radiation and thus patient dose

54
General principles associated with good imaging
performance

• Additional filtration
• For pediatric patients, total radiation dose must
  be kept low, particularly when high speed screen
  film systems or image intensifying techniques are
  used
• Not all generators allow the short exposure
  times that are required for higher kV technique
• Low radiographic voltage is frequently used for
  pediatric patients. This results in comparatively
  higher patient doses.

55
General principles associated with good imaging
performance

• Additional filtration
• Adequate additional filtration allows the use of
  higher radiographic voltage with the shortest
  available exposure times, thus overcoming the
  limited capability of such equipment for short
  exposures
• This makes the use of high speed screen film
  systems and image intensifier photography possible

56
General principles associated with good imaging
performance

• Protective Shielding
• For all examinations of pediatric patients, the
  examples for Good Radiographic Technique
  include standard equipment of lead-rubber
  shielding of the body in the immediate proximity
  of the diagnostic field
• Special shielding has to be added for certain
  examinations to protect against external
  scattered and extra-focal radiation

57
General principles associated with good imaging
performance

• Protective Shielding
• For exposures of 60 - 80 kV, maximum gonadal dose
  reduction of about 30 to 40 can be obtained by
  shielding with 0.25 mm lead equivalent rubber
  immediately at the field edge
• However, this is only true when the protection is
  placed correctly at the field edge

58
General principles associated with good imaging
performance

• Protective Shielding
• The gonads in "hot examinations", i.e. when they
  lie within or close (nearer than 5 cm) to the
  primary beam, should be protected whenever this
  is possible without impairing necessary
  diagnostic information
• It is best to make one's own lead contact
  shields for girls and lead capsules for boys
• They must be available in varied sizes

59
General principles associated with good imaging
performance

• Protective Shielding
• By properly adjusted capsules, the absorbed dose
  in the testes can be reduced by up to 95
• In girls, shadow masks within the diaphragm of
  the collimator are as efficient as direct
  shields. They can be more exactly positioned and
  do not slip as easily as contact shields
• When shielding of the female gonads is
  effective, the reduction of the absorbed dose in
  the ovaries can be about 50

60
General principles associated with good imaging
performance

• Protective Shielding
• There is no reason to include the male gonads in
  the scrotum within the primary radiation field
  for radiographs of the abdomen
• The same applies, usually, for films of the
  pelvis and micturating cystourethrographies. The
  tests should be protected with a lead capsule,
  but kept outside the field
• In abdominal examinations gonad protection for
  girls is not possible

61
General principles associated with good imaging
performance

• Protective Shielding
• In practice, the great majority of pelvic films
  show that female gonad protection is completely
  ineffective
• The position of all sorts of lead material is
  often ludicrous
• There are justifiable reasons for omitting gonad
  protection for pelvic films in girls, e.g.
  trauma, incontinence, abdominal pain, etc

62
General principles associated with good imaging
performance

• Protective Shielding
• The eyes should be shielded for X Ray
  examinations involving high absorbed doses in the
  eyes, e.g. for conventional tomography of the
  petrous bone, when patient cooperation permits
• The absorbed dose in the eyes can be reduced by
  50 - 70
• In any radiography of the skull the use of
  PA-projection rather than the AP-projection can
  reduce the absorbed dose in the eyes by 95

63
General principles associated with good imaging
performance

• Protective Shielding
• PA-projection, therefore, should be preferred as
  soon as patient age and co-operation permit prone
  or erect positioning
• As developing breast tissue is particularly
  sensitive to radiation, exposure must be limited
• The most effective method is by using the
  PA-projection, rather than the AP

64
General principles associated with good imaging
performance

• Protective Shielding
• While this is well accepted for chest
  examinations, the greatest risk is during spinal
  examinations, and here PA examinations must
  replace AP
• It should also be remembered that thyroid tissue
  should be protected, whenever possible, e.g.
  during dental and facial examinations

65
General principles associated with good imaging
performance

• Radiographic Exposure Conditions
• Knowledge and correct use of appropriate
  radiographic exposure factors, e.g. Radiographic
  voltage, nominal focal spot value, filtration,
  film-focus distance is necessary because they
  have a considerable impact on patient doses and
  image quality
• Permanent parameters of the apparatus such as
  total tube filtration and grid characteristics
  should also be taken into consideration

66
General principles associated with good imaging
performance

• Automatic Exposure Control
• Adult patients vary in size, but their variation
  is minimal compared to the range in pediatric
  patients from premature infants, weighing
  considerably less than a thousand grams, to
  adolescents approaching 70 kg
• Those investigating pediatric patients must be
  able to adapt to this range. One would expect
  that a device for automatic exposure control
  (AEC) would be helpful

67
General principles associated with good imaging
performance

• Automatic Exposure Control
• Many of the AEC systems commonly available are
  not satisfactory
• They have relatively large and fixed ionization
  chambers. Neither their size nor their shape nor
  their position is able to compensate for the many
  variations of body size and body proportion in
  pediatric patients
• In addition, the usual ionization chambers of
  AECs are built in behind a grid

68
General principles associated with good imaging
performance

• Automatic Exposure Control
• AEC-use may be associated with the use of the
  grid (where the grid is not removable) which is
  frequently unnecessary
• The optimal adaptation of the radiographic
  technique to the clinical needs requires the use
  of screen film systems of different speeds and
  different switch-off doses at the image receptor

69
General principles associated with good imaging
performance

• Automatic Exposure Control
• Screens and AEC chambers are wavelength
  dependant, particularly in the lower range of
  radiographic voltage, but these dependencies do
  not correspond with each other
• AECs lengthen the minimal exposure times
• All these factors must be considered when AECs
  are used in pediatric patients

70
General principles associated with good imaging
performance

• Automatic Exposure Control
• Specially designed pediatric AECs have a small
  mobile detector for use behind a lead-free
  cassette
• Its position can be selected with respect to the
  most important region of interest
• This must be done extremely carefully, as even
  minor patient movement may be disastrous

71
General principles associated with good imaging
performance

• Automatic brightness control
• Automatic brightness control (ABC) has to be
  switched off during fluoroscopic examinations
  where there are relatively large areas of
  positive contrast material to avoid excessive
  dose rates, e.g. full bladders

72
Guidance on implementation of quality criteria

• Quality Criteria are presented for a number of
  selected radiographic projections used in the
  course of routine types of X Ray examination
• They apply to pediatric patients with the usual
  presenting symptoms for the type of examination
  being considered
• They are to be used by radiologists,
  radiographers, and medical physicists as a check
  on the routine performance of the entire imaging
  process

73
Guidance on implementation of quality criteria

• However, the Quality Criteria cannot be applied
  to all cases
• For certain clinical indications lower level of
  image quality may be acceptable, but this should
  ideally always be associated with a lower
  radiation dose to the patient

74
Guidance on implementation of quality criteria
Under no circumstances should an image which
fulfils all clinical requirements but does not
meet all image criteria ever be rejected
75
(No Transcript)
76
(No Transcript)
77
Diagnostic Reference Doses in Pediatrics
Examples of Diagnostic Reference Doses in
Pediatrics, for standard five-year-old patients,
expressed in entrance surface dose per image, for
single views (from EUR-16261)
78
Diagnostic Reference Doses in Pediatrics
Examples of Diagnostic Reference Doses in
Pediatrics, for standardfive-year-old patients,
expressed in entrance surface dose per image,for
single views (from EUR-16261)
79
Part 14.1 Optimization of Protection in
Pediatric Radiology
IAEA Training Material on Radiation Protection in
Diagnostic and Interventional Radiology

• Topic 3 Recommendations for X Ray room and
  equipment

80
Recommendations for X Ray room and equipment to
be used in pediatrics

• Visibility of the patient and easy audio
  communication from the control panel
• High frequency generators of 600-800 mA with
  linearity from 50 until 120-150 kV
• Exposures of 3 ms should be possible. AEC devices
  should be specifically adapted
• Different control for the anode rotation and
  exposure (specially important for chest
  examinations to avoid respiratory movement)

81
Recommendations for X Ray room and equipment to
be used in pediatrics

• Low absorption materials and plastic cassettes
  should be used
• Antiscatter grid should be removable
• When using the grid, this should be Fixed
  (specific for pediatric) or with very fast
  movement due to the short exposure times
• Image intensifier (I.I.) of 15 cm can be the
  appropriate size for small patients. Higher sizes
  or multimode I.I. can produce worse images

82
Recommendations for X Ray room and equipment to
be used in pediatrics

• The use of additional filtration should be
  considered in pediatric X Ray equipment
• Mobile X Ray system for pediatrics should have
  the highest possible output
• Immobilization devices should be available in
  pediatric rooms

83
References

• European Guidelines on Quality Criteria for
  Diagnostic Radiographic Images in Paediatrics,
  July 1996. EUR 16261. Available at
  http//www.cordis.lu/fp5-euratom/src/lib_docs.htm
  
• ICRP Publication 34, Protection of the Patient in
  Diagnostic Radiology. Annals of the ICRP (2/3)
  1982.
• NCRP 68. Radiation protection in pediatric
  radiology, 1981.

84
References

• Cook JV, Shah K, Pablot S, Kyriou J, Pettet A,
  Fitzgerald M. Guidelines of best practice in the
  X-ray imaging of children. Edited by the Queen
  Marys Hospital of Children. London 1998.
• Guidelines on education and training in radiation
  protection for medical exposures. Radiation
  Protection 116. European Commission 2000.
  Available at http//europa.eu.int/comm/environmen
  t/radprot

85
References

• Guidance on diagnostic reference levels (DRLs)
  for medical exposures. Radiation Protection 109.
  European Commission 1999. Available at
  http//europa.eu.int/comm/environment/radprot
• Rational use of diagnostic imaging in pediatrics.
  WHO, 1987.

86
Summary

• Particular attention should be given to technical
  specifications of X Ray equipments and protocols
  used in X Ray pediatric radiology.
• Radiologists and radiographers should be
  specifically trained and the higher
  radiosensitivity of the patients should be taken
  into account.
• General rules of protection and guidelines are
  presented.