Protection of Patients Flashcards
Persons are medically exposed as part of their
diagnosis or
treatment
Basic Principles of Radiation Protection which can be applied:
Principles of Justification
Optimization (ICRP and BSS)
Dose limits are not applicable, but ____ apply to patient dose levels
Diagnostic Reference Levels (DRLs)
Investigation of doses that exceed the DRLs is
strongly recommended
principally the exposure of persons as part of their diagnosis or patient
Medical Exposure
incurred at work, and practically as result of work
Occupational Exposure
including all other exposure
Public Exposure
Exposures incurred knowingly and willingly by individuals such as family and close friends helping either in hospital or at home in the support and comfort of patients
Medical Exposure
Exposures incurred by volunteers as part of a program of
biomedical research (Medical Exposure)
Framework of Radiological Protection for Medical Exposure
Justification
Optimization
Use of dose limits is not applicable
Dose constraints and Diagnostic Reference Levels are
recommended
decision to adopt or continue any human activity involves a review of benefits and disadvantages of the possible options
Justification of a Practice
most of the assessments needed for justification of a practice are made on the
basis of experience
professional judgement
common sense
use of radiation in medicine is accepted as doing good than harm
general level
specific procedure with a specific objective ex. chest radiograph for patients showing relevant symptoms
generic level
the application of the procedure to an individual person
third level
once the procedure is generically justified,
no additional justification is needed for simple diagnostic investigations
usually applied at two levels
optimization
optimization usually applied at two levels
design and construction of equipment installations
day to day radiological practice (procedure)
may reduce the quantity as well as the quality of the information provided by the examination
reducing the patient dose
means that doses should be “as low as reasonably achievable”, compatible with achieving the required image quality objectives
optimization
there is a considerable scope for dose reductions in diagnostic radiology (ICRP 103)
optimization of protection
simple, low-cost measures are available for reducing doses without loss of diagnostic information (ICRP 103)
optimization of protection
optimization of protection in diagnostic radiology does not necessarily mean ____
the reduction of doses to the patient
improve the contrast of the image but increase the dose by a factor of 2-4
Anti-scatter grids
radiologic activities are geared towards
minimizing the radiation exposure of radiologic personnel
minimizing radiation dose to patients during x-ray examination
monitoring of radiation dose/exposure for radiologist ad rad tech
occupational radiation monitors
monitoring of radiation dose/exposure for patient dose
estimated using phantoms and test objects in simulation
if ____ are adopted, occupational radiation exposure and patient dose can be kept acceptable low
radiation control procedures
the frequency of x-ray examination is increasing among all age group at a rate of
approx. 18% per year in the united states
these are of concern in the increasing risk of Medical Exposure
acute effects on superficial tissues after angiointerventional procedures
possible late effects of diagnostic xray exposure
according IAEA these may unnecessarily expose patients to increased radiation levels
overuse of high-tech scanning procedures
annual meeting of European Radiation Dosimetry Group
EURADOS
in cancer care, ensuring that the right dose of radiation targets the tumor
without doing damage to neighboring cells is utmost importance
optimization of patient radiation protection requires
periodic evaluation of doses
image quality
Rad tech should be aware of the interdependence between
technical factors
dose
image quality
periodic measurement of the ____ and the comparison with the ____ will permit the detection of changes due to equipment or radiographers
entrance patient dose
diagnostic reference levels
a value of dose, dose rate or activity selected by professional bodies in consultation with the regulatory authority to indicate a level above which there should be a review …..
diagnostic reference levels
diagnostic reference levels are intended:
- to be reasonable indication of doses for average size patient
- to be established by relevant professional bodies in consultation with the regulatory authority
- to proved guidance on what is achievable with current good practice …
- to be applied with flexibility to allow higher exposures…
- to be revised as technology and techniques improve
corrective actions should be taken as necessary if doses or activities ____ the DRLs and ____
fall substantially below
images do not provide adequate clinical image quality
in general radiography and fluoroscopy with xray mobile equipment, the source-to-skin distance should
not be less than 30cm
in radiography and fluoroscopy with fixed equipment, the source-to-skin distance should
not be lower than 45cm
fluoroscopy equipment without image intensifiers
must be replaced
Evaluation include both
image quality
patient dose
all xray equipment must conform to applicable standards of the __
International Electrotechnical Commission (IEC)
ISO
equivalent national standards
adequate filtration in general radiology
2.5mm Al
significantly reduces the patient dose due to low energy xrays which do not contribute to the image formation
adequate filtration
added filtration should be check for maintenance by
half value layer
filtration for mammography
0.03mm thickness of Molybdenum
this should be available for fluoroscopic examinations to allow measurement of the elapsed fluoroscopic exposure time
timer
fluoroscopy should be controlled with a
dead man switch
when using mobile radiographic equipment ___ is needed
high instantaneous electric power supply
to avoid retakes in mobile radiographic equipment
battery is fully charged
use of appropriate screen-film combination
“fastest” to assure lowest patient dose
results in significant patient dose reductions
use of cassettes, grids, and tables of carbon fiber material
the patient entance air kerma rate should not exceed
50mGy/min
it is advisable ___ compatible with the image to minimized patient dose
highest kvp (lowest mAs)
should be used when imaging non-cooperative patients
short exposure times
patient should wear ____ when gonads are expose
gonadal shielding
should be related to the level of risk
communication
if a fetal dose are ____ , more detailed explanation may be necessary
above 1 mGy
for pregnant women ___ are preferable to minimize the uterus dose
PA abdominal projections
for skull examinations, eye lenses are better protected in
PA projection
should be used for scoliosis imaging to minimize breast dose
PA projections
CT examinations should be done with the ___
minimum possible number of slices
fluoroscopy times should be
minimized
