Do you think always patients can

Come to x ray department?

Prepared by Ali B. ( Lecturer, Department of MRT,

1
AAU ) 03/14/2022
 Mobile and Portable X-ray Equipment

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 2

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 3
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 4
 Learning Objectives

At the end of lesson, the student should able to:-

• List type of mobile x-ray units.
• Briefly explain the principle operation of mobile x-ray
units.
• List the advantages and limitation of mobile x-ray units.
• Briefly explain the special consideration for mobile x-
ray units.
• Briefly explain the safe handling for mobile x-ray units.
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 5
 Introduction

• If it is not possible to take a patient to the radiology

department
• In-patients who could not leave their beds
• Surgeons who required x-ray control guidance
during the course of their work in the operation
theatre

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 6

 Where are mobile & portable
equipments employed?

Intensive Care Unit

Coronary Care Unit
High Dependency Unit
Resuscitation / Major trauma
Wards
Minor Ops / Theatre (including recovery)
Special Baby Care Unit
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 7
 Why these areas are identified?

• This is because
 patients are too ill to be moved
 patients are immobilized in bed
 patients are undergoing surgery in OR

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 8

 For what kinds of patients the movable
equipment are employed?
• Pediatrics
• Elderly patients
• Confused patients
• Unconscious patients
• Trauma patients
• Very ill patients
• Immunosuppressed patients
• Immobile patients
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 9
 Movable x-ray equipment

• Portable x-ray equipment

• Mobile x-ray equipment

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 10

 PORTABLE - refers to a small hand held unit
 Portable equipment means that the x-ray unit is
capable of being carried. It does not need more
than one person to carry it.
 Portable equipment is very simple to use and can
be packed in to carrying cases
• Have the ability to be taken apart into major parts
and carried about

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 11

 Cont…

• Used for x-ray examination even outside the

hospital
• Primarily designed and intended to be used in
specific cases:
• nursing homes, private homes
• military field clinics, hospitals
• In general - where the X-ray machine must be brought to
a patient
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 12
 Cont…

• The major units include tube stand, control unit,

tube head that contains the HT transformer.
• Each composite part is usually light enough to
carry but the composite weight may be too heavy
to carry
• In majority - radiography and dental devices

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 13

 Portable Equipment

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 14

 Physical features

• Size
• Weight
• Wheels
• Range of movements
• Electrical supply
• Maintenance & safety
• Cost
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 15
 Advantages

• Advantage: light, easy to carry, to transport

• Permit radiographic examination in locations only
limited by the availability of a standard electrical
supply

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 16

 Limitations

• Low output a typical maximum is 80 KVp at 15

mA for 1 second.
• Difficult to control X-Ray safety aspects of
radiation protection.
• Appropriate quality of the examination is a
question, image quality, dose to the staff and
public.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 17

 Portable x-ray set can be considered
under the following basic features

• The x-ray Tube

• The tube stand
• The high tension generator
• The Control unit
• The Radiographic output and main requirements

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 18

 Cont…
• X-ray tube and its high tension generator are enclosed in one earthed
metal tank filed with oil called a tube head. this is to make
equipment:
• Simpler
• Lighter
• Less expensive
• Easier to move
• No high tension cables are necessary
• The tube is a small stationary anode x-ray tube operating with self
rectified
Prepared by Ali B.circuit
( Lecturer, Department of MRT, AAU ) 03/14/2022 19
 Control unit

• The control unit is housed in small box or control

desk.
• The low tension cables coming from the tube stand
plugs into a socket
• On the control unit the following features are
found.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 20

 Cont…

• A main On/Off switch

• An indicator lamp
• A line voltage compensator
• A kilovolt-selector
• Pre-reading kilovolt-meter
• Milliampere-selector
• A timer
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 21
 Portable unit which can be dismantled and
carried

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 22

• Mobile radiography: equipment both for radiography
and fluoroscopy, radiographic equipment that has
wheels that enable it to be moved to a specific location
to be used
• Mobile - Full powered institutional units much heavier
- motor or muscle driven
• Mobile Radiography units are used to examine patients
at the bedside when they cannot be moved to the
Radiology Department.
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 23
 Cont…

• Mobile equipment means the x-ray equipment

capable of being moved. It is mounted on wheel
and can be pushed by human power.
• Mobile equipment is larger and heavier than
portable sets.
• It can not be separated into smaller components &
it does not lend itself to use outside the hospital.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 24

 Cont…

• Transportable x-ray equipment to bring imaging

services to pts
• Commonly performed in pts room, ER, ICU,
surgery and recovery rooms, nursery and neonatal
units
• Mobile x-ray was first used in military
• Units were carried to field sites

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 25

 Cont…

• Not as sophisticated as stationary units

• Typical unit has controls for setting kVp and mAs
• mAs range = 0.04 to 320
• kVp = 40 to 130

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 26

 Cont…

• The image quality from such examinations is not as

good as that obtained from the Radiological
Department examinations, mainly due to the
difficulty in the correct set up of the equipment in
relation to the patient position in bed.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 27

 Cont…

• Due to the fact that mobile x-ray units are used at

areas not specifically designed for X-ray usage, It
is necessary to take additional precautions in order
to minimize the dose to the patient under
examination, as well as to the neighboring patients,
the ward staff and the personnel.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 28

 Construction of Mobile Unit:
1.High generation tank containing the HT transformer
2. Handle for pushing the unit.
3. Control unit. 4. Lock. 5. Tube Column.
6. Bowden cable allowing vertical movement of
the cross arm.
7. Movement of the cross arm.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 29

8. Hinge joint to allow extension of the cross arm.
9. HT cables.
10. Column base allowing rotation of the cross arm
around column.
11. Base plate.
12. Large wheels for easy movement.

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Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 31
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 32
 Some of the general rules
• The exposure hand-switch cable must be at least 2 m long
to allow radiographer/RT to stand distant from irradiated
patient
• Lead protection must be used for personnel not
involved with the examination
• Protect other staff not involve with the examination
• The cable must be long enough for the equipment to be
used in most locations
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 33
 Cont…

• Should provide a convenient mains outlet socket

• The cable must be wound onto a wheel-type
storage drum built into the equipment, when not in
use to protecting it from physical damage
• Using extension cable is not recommended

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 34

 Mobile units classification

• They are classified by two ways: out put and power

supply.
• By out put
1. Low-powered
2. Average –powered
3. High-powered

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 35

 Main requirements

Electrical energy source

• Directly from the mains voltage supply in this
case static generator is installed permanently
• A Capacitor can be charged from the mains
voltage to the required potential difference and
discharged through the x-ray tube
• Battery design, which can provide the energy
required by an x-ray generator
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 36
 Cont…

• Current drawn is related to the x-ray output-sets which

function at high maximum kilo voltage and ma draw
large currents.
• Any x-ray set which must not draw a large current must
be limited in it’s radiographic out put.
• Portable set must be capable of being operated from a
low current supply.
• Any portable equipment is connected by length of cables
to the plugs
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 37
• By mains requirement:
1. Direct main supply unit
2. Capacitor-discharge Unit 
3. Battery Powered Unit
              

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 38

 Direct main supply

 Energy may be drawn for X-ray exposure directly

from the mains voltage supply.
 This is convenience if there is no need for the
energy to be carried around within the mobile unit.
 But cable resistance and supply variation at
different locations where the unit is used can raise
difficulties affecting image quality.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 39

• The cable must be long enough (2 meter) for
equipment to be used in most locations, provided
there is a convenient mains outlet socket, but not so
long that its resistance becomes significant.
• The cable should be manufactured to tolerate
physical damage

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 40

 Capacitor discharge unit
• Energy stored in the capacitor.

• Charge the capacitor up to the kilo voltage required for the exposure

• The capacitor becomes the source of power for the x-ray exposure.

• The capacitor disconnected from the charging circuit and connected

to the x-ray tube.

• Greater capacitance provided more energy.

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Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 42
• Small in size and light in weight, because there is no
H.T.T.
• This unit has the advantage of storing energy in the
form of electric charge for later use for X-ray exposures.
• Therefore, it can be used in places where there is no
electricity, or no a convenient mains outlet socket, or
there is electrical power but not adequate (not enough to
operate the X-ray unit), or suffers ‘drops’ in its values.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 43

• The unit has the advantage of providing high X-ray
output (usually high mA). The given kVp is from
30 or 40 up to 100 to 125 kVp and 500 mAs.
• Shorter exposure time. By using grid-controller,
this grid plate is exist between the anode and the
cathode in the tube.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 44

• It has no timing control device since only the kVp
has to be selected, so the mAs depends on the kVp.
As the kVp in the capacitor discharge falls the mAs
does so.
• Simple in operation, it can be supplied by any
voltage from 60V to 220V (so we shouldn’t worry
from voltage fluctuation).

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 45

• Provides consistently reliable output and results
(uniform wave), which has the advantage of less
absorbed dose to the patient and good image
quality.

• This consistency happened because the main

voltage and resistance variations only have their
effects upon the act of charging the capacitor,
which takes place just before the X-ray exposure is
made.
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 46
• Capacitor discharge is usually limited so that the
drop in kVp is only 35% on heavy exposure.

• The disadvantage that it has the limitation in

exposures. Few times of exposure needs capacitor
charge

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 47

 Battery powered

• This is called also cordless mobile unit (mains-

independent).
• This unit use batteries as a source of energy for X-
ray exposure.

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 48

• Two 12volt batteries used.
• If well-maintained should last for up to 2 years.
• The unit should be left connected to the mains
every night and all times when the unit is idle.

• This will recharge the battery

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 49
Advantages:
(1) This machine can be used freely, provides wide
range of satisfactory kVp & mAs.
(2) This machine could be recharging less frequently
that the capacitor one. Some machine allows you to
take up to 500 exposures without re-charging.
Disadvantages:
• It needs special care and maintenance.
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 50
 The basic design for a mobile
unit
• A wheeled base
• Built in X-ray generator
• Control panel
• Supported X-ray tube

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 51

 Physical Features of mobile equipment

• It is characterized in terms of
• Size
• Range of movements
• Wheels and Drive
• Electrical supply

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 52

 Technical Considerations 

• 3 important technical factors must be clearly

understood to perform optimum mobile
examinations
• Grid
• Anode-heel effect
• Source–to–image receptor (SID)

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 53

 Grid 

• Must be level!
• Grid and x-ray beam must be properly centered
• Correct focal distance must be used
• Best grids for mobile radiography have ratios of 6:1 or
8:1 and a focal range of 36 - 44 inches

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 54

 Anode Heel Effect 

• Heel effect increases with short SID, larger field

sizes, and small anode angles
• Short SID’s and larger field sizes are more
common in mobile radiography
• Pay attention to cathode and anode sides of tube -
usually marked on tube housing
• Correct placement of anode-cathode with regard to
anatomy is essential

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 55

 SID- Mobile Units 

• Should be maintained at 40 inch (102 cm)

• Standardized distance ensures consistent images
• Longer SID requires increased mAs, which results
in longer exposure time
• Increases risk of imaging motion

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 56

 Scatter Radiation and Mobile Radiography

• RT may receive a high exposure

• Stand at a right angle to tube and scattering
object
• Lead aprons should be worn
• Maximize your distance from pt.
• Lead shielding must be used for all pts unless it
will interfere with examination  
 

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 57

 Safest Place to Stand

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Before starting the examination:

• Check pt’s chart for order

• Let nurse’s station know of your presence and purpose
• Obtain assistance when necessary
• Identify pt and introduce yourself with your title
• Explain exam and ensure it is appropriate and correct
• Move any interfering equipment carefully
• Politely ask any visitors to leave

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 59

 Cont…

• Move chairs, IV poles, wastebaskets, etc. out of

path of machine
• If exam in supine position, move base of machine
to middle of bed
• If seated upright, base at end of bed
• Lateral and decubitus positions, place base parallel
or perpendicular to bed

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 60

 Cont….

• Make sure collimation is not open larger than IR

size
• Check CR and IR alignment to prevent distortion
• Use consistent system for keeping exposed and
unexposed IRs separate
 

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 61

 Cont…

• Should display standard technical factors for all

projections performed with machine
• Caliber should also be available for accurate
patient measurement

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 62

• http://
www.radtechonduty.com/2015/05/xray-radiologic-t
echnologist-radiation-protection.html

Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 63

 Common Mobile Radiographic
Procedures
• Chest
AP , PA or decubitus
• Abdomen
AP, decubitus
• Orthopedic
Extremities, spine or pelvic with the patient in
traction and immobilizing devices
Prepared by Ali B. ( Lecturer, Department of MRT, AAU ) 03/14/2022 64
 Examples: AP chest

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 Neonatal AP AXR

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