Chapter Five
Protection of the Patient During Diagnostic Radiological Procedure
5.1 EFFECTIVE COMMUNICATION
 Total patient care begins with effective communication between the
radiographer and the patient .
 When verbal (words) and nonverbal (unconscious or body language )
messages are understood as intended, communication is effective .
5.1.1 Communication encourages :
1. Closeness
2. reduces anxiety and emotional stress .
3. Enhances the professional image of the technologist as a person who cares
4. increases the chance for successful examination .
 Patient radiation protection begins with clear instruction ,so patient
understands what must be done and can more fully cooperate .
 When procedures are not explained or are poorly explained to the patient he
or she faces the fear of unknown and experiences anxiety and nervousness.
This stress increases the patient state of mental confusion and may lead to
depression. This problem can be avoided by spending adequate time with the
patient to explain the procedure in simple terms. And answering his questions
.
 Everyone within the department should always function as humanistic
professional .
 Repeat radiographs can sometimes be attributed to poor communication
between the radiographer and the patient . this will result in unnecessary
repeat exposure .
IMMOBILIZATION :
 If a patient moves during radiographs exposure, the image will be blurred ,so
the image have little or no diagnostic value and that will lead to repeat
examination resulting in additional radiation exposure for the patient and
radiographer .
 to decrease the problem of voluntary motion (motion controlled by will i.e.
skeletal muscle )the patient should be immobilized during exposure
 Involuntary motion e.g. motion of digestive organ can be reduced by
reducing exposure time .
5.3 BEAM LIMITATION DEVICES
5.3.1 Aperture diaphragm
a flat piece of lead with a hole of a designated size and shape cut in its
center , is placed directly below the window of the x-ray tube to limit the
radiographic beam to a fixed size so that the beam covers a given size film at a
given distance .
5.3.2 Cones
 Cones are circular metal tube ( in the form of flared or straight cones ) which
attach to the x-ray tube housing or variable rectangular collimator to limit the
radiographic beam to a certain size and shape .
5.3.3. Collimators
The most versatile device for defining the size and shape of the
radiographic beam . The radiographer should ensure that collimation is adequate
by applying the following principle :collimate the radiographic beam so that it is
no larger than image receptor (the film ), Limiting the beam to the area of
clinical interest decreases the amount of tissue irradiated and thereby minimizes
patient exposure by decreasing the amount of scattered and absorbed radiation .
5.3.4 Filtration
Removes low-energy photons (20 KeV or lower i.e. long wavelength or
soft x-ray ) from the beam by absorbing them and permits higher energy
photons to pass through .This reduces patient dose .
There are two types of filtration :
1. Inherent filtration
2. Added filtration
inherent filtration includes the glass envelope encasing the x-ray tube , the
insulation oil surrounding the tube and the glass window in the tube housing .
Added filtration usually consists of sheet of aluminum or its equivalent of
appropriate thickness .
5.3.5 Gonadal Shielding Devices
Used during radiological procedures to protect the reproductive organs
from exposure to the useful beam when they are in or within close proximity
(about 5 cm ) of a properly collimated beam .
It should be a secondary protective measure , not substitute for a property
collimated beam . proper collimation of radiation beam must always be the first
step in gonadal shielding .
Types of Gonadal shielding :
1. Flat contact shields .which can be placed over the patient’s gonads to provide
protection from x-ray .
2. Shadow shields -suspends from above the radiographic beam defining
systems and casts a shadow over the protected body area, the gonads.
3. Shaped contact shields - Shaped contact shields (cup like) can be held in
place with the use of a suitable carrier e.g. carrier-disposable brief .
4. Clear Lead e.g. clear lead filter with breast and gonadal shielding devices .
5.3.6. Exposure Factors
The use of higher kilovoltage (kVp) and lower milliamper and exposure time in
seconds (mAs) reduces patient dose ; The use of high kVp and low mAs results
in a high-enrgy , penetrating x-ray beam and a small patient absorbed dose . The
use of low Kvp and high mAs results in a low-energy x-ray beam , most of
which is easily absorbed by the patient
5.3.7 Film-Screen combinations :
Choice of the film-screen combination affects patient dose. Since high-speed
film and screens require less x-ray exposure because of their greatly enhanced
sensitivity , their use significantly reduces patient dose.
5.3.8 Types of radiographic films :
There are two basic types of radiographic film :
1. non-screen film ((direct exposure film )
2. screen film .
Screen film is manufactured in different speeds for use with intensifying
screens, which enhance the action of x-rays .Film speed influences radiographic
exposure time .When the amount of silver bromide crystals contained in the
film emulsion is increased , the speed of the film is increased which means that
less radiation exposure is required to obtain an image . As radiographic
exposure decreases , patient dose decreases .
5.4 OTHER IMPORTANT DIAGNOSTIC EXAMINATIONS AND
IMAGING MODALITIES :
4.4.1 Patient dose in mammography
Mammography can detect breast cancer when it is so small that it is nonpalpable . there is still some concern, however, in certain quarters as to whether
the benefits to the patient in terms of detection of early breast cancer from
routine screening outweighs the small risk of causing a radiogenic cancer in the
future .
5.4.2 Patient dose in CT :
The dose distribution resulting from a CT scan is not the same as the dose
distribution occurring in routine radiological procedures . because CT scanners
use an x-ray beam that is tightly collimated, the amount of scatter radiation
generated is lower than the scatter produced by the less tightly collimated
radiographic beam .
5.4.3 Pediatric considerations:
When considering the potential for biological damage from exposure to ionizing
radiation , children are more .vulnerable to both the late somatic effects and
genetic effects of radiation than are adults .Hence , children require special
consideration when undergoing diagnostic radiological studies .Appropriate
radiation protection methods must be used for each procedure .
In general , smaller doses of ionizing radiation suffice to obtain useful images in
pediatric radiological procedures than are necessary for adult radiological
procedures .
Patient motion is a frequently a problem encountered in diagnostic pediatric
radiography .because of the limited ability of the children to understand the
radiological procedure and their limited ability to cooperate ,so , radiographer
should use the effective immobilization techniques and devices .
Essentially , the same patient protection methods used to reduce the radiation
exposure for adults may be employed to reduce the radiation exposure for
pediatric patients .
5.4.4 Pregnant patient :
Because there is evidence that the developing embryo or fetus in is especially
radiation sensitive . special care is taken in medical radiography to prevent
unnecessary exposure to the abdominal area of pregnant females . If the
physician feels it is in the best interests of a pregnant patient to undergo a
radiological examination , the examination should be performed without delay
and a special efforts should be made to minimize the dose of radiation received
by the patient’s lower abdomen and pelvic region .This can be accomplished by
1. selecting technical exposure factors that are appropriate for the examination
2. adequate collimating the radiographic beam
3. when the patient’s lower abdomen and pelvic region does not have to be
included in the area to be irradiated , it should be protected with a lead apron ,
so that a developing embryo or fetus does not receive unnecessary radiation
exposure .
The NCRP stated that “This risk (radiation risk to pregnant woman) is
considered to be negligible at 5rad or less when compared to the other risks of
pregnancy , and the risk of malformations is significantly increased above
control levels only at doses above 15 rad . Therefore , the exposure of the fetus
to radiation arising from diagnostic procedures would very rarely be cause ,by
itself, for terminating a pregnancy . If there are reasons , other than possible
radiation effects , to consider a therapeutic abortion , such reasons should be
discussed with the patient by the attending physician , so that it is clear that the
radiation exposure is not being used as an excuse for terminating the pregnancy
“
To avoid the probability of the pregnancy a 10 days role should be applied
where possible