Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY ACCESSORY EQUIPMENT

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER TWO

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY ACCESSORY EQUIPMENT

CRT04208 · Radiology Quality Assurance

Study Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY ACCESSORY EQUIPMENT using the sections below. Use the topic navigation to continue through Radiology Quality Assurance.

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY & Imaging – ACCESSORY EQUIPMENT

2024/2025

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

AIM

To provide the knowledge and practical skills necessary to establish and carry out a quality control program for accessory equipment

OBJECTIVES

Understand and carry out quality control procedures, evaluation and recommend action

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

COLLIMATOR

Visual inspection
Accuracy of scales
Change a light bulb
Light beam / X-ray beam alignment and centring

Lead shutter efficiency

The collimator (light beam diaphragm), provides the radiographer with an easy to use , accurate, method of controlling the size of the x-ray field and placing it over the area of interest, thus reducing the radiation dose to the patient and improving the quality of an image The collimator receives much use and is vulnerable to knocks, often resulting in inaccuracy of the light beam / X-ray beam coincidence, blown light bulbs, electrical and mechanical problems

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY & Imaging

ACCESSORY EQUIPMENT

VISUAL INSPECTION

Rotation.
Stability
Knobs for shutter control
Accuracy of shutter setting
Shutter chain drive
Shutters
Housing
Window
Light timer
Timer switch
Cables
Plugs
Light bulb

Light / x-ray beam alignment

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

ACCURACY OF THE SCALE TEST

The aperture size scales on the collimator used to set the aperture size, so it is advisable to make sure that the scales are accurate Inaccuracy of scales may lead to inaccurate collimation

FREQUENCY OF TEST

6 monthly

EQUIPMENT REQUIRED

Collimator to be tested
100cm rule

2024/2025

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

ACCURACY OF THE SCALE TEST

METHOD

Set 100cm focus to tabletop distance Using the 100cm FFD scale on the collimator, set various aperture sizes with the light on and measure the resultant light areas at table top level Compare with setting on the collimator

EVALUTION

Light area measured should be the same as the setting on collimator

ACTION

If settings are not accurate and the solution is not a simple one, call an x-ray engineer

File a report

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY & Imaging

ACCESSORY EQUIPMENT

CHANGING A LIGHT BULB

A light bulb can fail at any time without waning. It is important then, to have the correct spare bulb readily available Staff should be capable of replacing a faulty bulb

FREQUENCY

As necessary

EQUIPMENT

Suitable light bulb
Cloth or tissue

Screwdriver

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

CHANGING A LIGHT BULB

METHOD

Switch off the power
Remove relevant collimator housing

Check that spare is the correct type Before removing the old bulb, check to see if the replacement bulb must be fitted a specific way round Replace faulty bulb with the new one If the bulb is of the quartz type, ensure that it is not handed with bare fingers, as body oil on the bulb will shorten its life Replace housing and tighten screws

Test

Ensure that the spare bulb is replaced as soon as possible

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LIGHT BEAM / X-RAY BEAM ALIGNMENT TEST

The purpose of the light in a collimator is to allow more accurate collimation of the x-ray beam. The light must coincide with the x-ray beam. The light beam relies on the accurate positioning of the light bulb and angled mirror inside the collimator Should either the mirror or light bulb be dislodged, then errors in collimation could occur, resulting in areas of interest being excluded from the field, or too large an area being irradiated

FREQUENCY OF TEST

6 monthly

As necessary

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LIGHT BEAM / X-RAY BEAM ALIGNMENT TEST

EQUIPMENT REQUIRED

One 24x 30 cm loaded cassette

Alignment test tool, commercially made test tools are available, but a simple alternative is to use eight coins or four paper clips Lead marker or ninth coin

METHOD

Make sure that the table is level and the central ray at 90° to the tabletop
Place a loaded cassette on the tabletop face up
Set a FFD of 100cm

Switch on the collimator light

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LIGHT BEAM / X-RAY BEAM ALIGNMENT TEST

METHOD

Centre to the middle of the cassette Collimate to within the edge of the cassette, leaving a 3cm border all round, that is outside the light field Place the coins in pairs, so that, where the coins touch, coincides with the edge of the light area All four borders of the light must be marked in this way Place the lead marker within one corner of the light field so that the film can be related to the light /x –ray field and hence the collimator shutters Make an exposure sufficient to blacken the film Process the film

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LIGHT BEAM / X-RAY BEAM ALIGNMENT TEST

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

The purpose of the grid is to reduce the amount of low energy photons reaching the detector. Although the quality of the image is improved, it does mean a significant increase in exposure, and therefore dose to the patient.

A grid looks like a simple thin sheet of soft metal, but it is in fact a precision made of equipment and easily damaged. It is made up of a large number of fine lead strips interspaced between radiolucent strips. If the lead strips become distorted the grid will be less efficient and irregular densities will be created on the film If the grid is used wrongly, abnormal densities ( grid cut off) will be produced e.g. a focus grid used up side down will create reduction in density the further the area is from the centre line

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

SPECIFICATIONS

The detail of the grid structure should be marked on the surface of the grid either by a label or imprinted into the metal GRID RATIO :- The ratio of the height of the lead strips to the distance between them GRID LINE:- The number of lead strips in a grid. Stated as the number of lead strips to the centimeter ( or to the inch ) FOCAL RANGE:- Grids are designed to be used within given focus film distances ( source image distances ) dependent on the way the lead strips have been focused GRID LINE DIRECTION :- The direction in which the grid lines travel is indicated by a line down the centre of the grid on the tube side. Cross – hatch grids have second line running at 90° to the first TUBE SIDE:- The tube side is shown by a label stating TUBE SIDE, or an x-ray tube symblol. The lead strips direction line also indicates the tube side

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

CARE OF THE GRID:-

Stationary grids should have an added, rigid, PVC protective cover When a protective cover is added the grid specifications must be recorded on the new cover for future reference Do not bend, drop or dent the grid

Clean regularly
Store in a safe place

USE OF A STATIONARY GRID

Use a grid that is the same size as the cassette
Place the grid against face of cassette with northing between it and the cassette face
Check that the tube side of the grid is toward the tube

tched off when not in use and any safety lock keys removed

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

USE OF A STATIONARY GRID

Use strips of adhesive tape to hold the grid in place
Use the recommended focus film distance ( source image distance) for that grid

The x-ray beam must not be angled across grid lines

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

GRID LINE DAMAGE TEST

FREQUENCY OF TEST

6 monthly
As necessary

EQUIPMENT REQUIRED

Grid to be tested
One loaded cassette, same size as grid
One lead marker

METHOD

VISUAL INSPECTION

Dents, bends, creases, damaged corners
Specifications marked

Cleanliness

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID
X-RAY
Place cassette on tabletop, face up
Place grid to cover cassette, tube side up
Set a FFD in the middle of the known focal range of the test grid or 100cm
Centre to middle of grid
Central ray at 90° to cassette / grid
Collimate to cover cassette / grid
Set an exposure of 50kV 10mAs
Expose

Process film

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

EVALUTION

Is grid line pattern regular ?
Is overall density even ?

ACTION

If the grid line pattern or density is unacceptable repeat the test using FFDs of 10cm either side of that used in the first test If the images are still unacceptable, replace the grid File a report

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LEAD RUBBER APRONS AND GLOVES

Lead readily absorbs radiation and is used in many forms and thicknesses in the field of radiation protection. e.g. lead sheet, lead rubber, lead acrylic Lead rubber has advantage of being flexible and therefore be made into items which can be worn e.g. aprons and gloves.

Lead rubber tends to deteriorate over a period of time, with regular use and mishandling. Regular care, cleaning and testing are important

OTHER LEAD RUBBER ITEMS

Gonad shields
Thyroid shields
Small sheets of differing size

Shielding on screening units

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

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LEAD RUBBER APRONS AND GLOVES

CARE
Weekly cleaning or as necessary. Clean with soap and water
Never fold any item of lead rubber
Aprons should be hung up using strong, specially designed hangers
Store gloves flat or upright on a custom made holder

Do no store near a heat source

The lead equivalent ( effectiveness) of all forms of lead rubber should be known. Aprons for instance are designed only to protect against scatter. They have a lead equivalent of between 0.25mm and 0.5mm. Lead sheet may have a lead equivalent of 2.0mm or 3.0mm

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LEAD RUBBER APRONS AND GLOVES

VISUAL INSPECTION TEST

FREQUENCY OF TEST

6 monthly
As necessary

EQUIPMENT REQUIRED

Items to be tested

METHOD

Check effectiveness and condition of fastenings on aprons ( if any)
Inspect surface covering for tears or sign of deterioration
Inspect all seams where appropriate
Check apron hanger devices

Assess storage location

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LEAD RUBBER APRONS AND GLOVES

EVALUATION

General condition and cleanliness
Possibility of cracks
Storage location and hanging devices
Are staff using the apron hangers

ACTION

Initiate any repairs or cleaning required
Carry out x-ray check
Relocate storage location if unsuitable
Re-design hangers if unsuitable
Re-educate staff if the are not hanging / storing items correctly
Replace if necessary

File a report

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

TEST TO DETECT CRACKING OF APRONS OR GLOVES

FREQUENCY OF TEST

Yearly
As necessary

EQUIPMENT REQUIRED

Screening x-ray unit (if a screening unit is not available, use a general purpose unit and 35cm x 43cm cassettes) Items to tested

METHOD

Spread article to be tested on the tabletop
Use screening system or examine whole article.

Use different kVps

If a general purpose x-ray unit is to be used, place cassettes under test article and separate exposures. Ensure that the whole article is examined

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

TEST TO DETECT CRACKING OF APRONS OR GLOVES

EVALUTION

Look for cracks or other abnormal variations of density in the image

ACTION

Items found to be defectives should be replaced Items being withdrawn can be cut up into smaller pieces, avoiding the cracked sections. These can be used for gonad shielding or shielding parts of the film File a report

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

A useful aid to maintaining the position of the patient. A range of pad sizes and shapes should be available in each x-ray room. They must be radiolucent Sets of film foam pads are available from manufacturers ( a polyethylene foam is commonly used ) pads may be improvised using other materials but they must be checked for radiolucency

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

ROUTINE CARE

Care of positioning pads should be ongoing
Try to minimize the risk of contamination by:
Contrast media
Plaster of paris
Blood
Urine
Inspect and wash regularly

Do not use for any other purpose

It may be preferable to cover with waterproof radiolucent material, or removable cotton covers or both

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

POSITIONING PAD TESTS

Visual
X-ray

VISUAL TEST

FREQUENCY OF TEST

Weekly
As necessary

EQUIPMENT REQUIRED

Pads to be inspected

INSPECT FOR:

Likelihood of contamination

General cleanliness

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

INSPECT FOR:

Shape
Smell
Particles breaking off
Firmness

EVALUATION

Unhygienic ?
Likelihood of contamination by radio opaque substances ?

Shape, firmness, general deterioration ?

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

ACTION

Wash and re –test if necessary

If there is a likelihood of contamination with a radiopaque substance then carry out the x-ray test If the pad has deteriorated to the extent that it no longer fulfil its function effectively then replace it File a report

X-RAY TEST

FREQUENCY OF TEST

6 monthly

As necessary

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

EQUIPMENT REQURED

X-ray unit
Pads to be tested
Loaded cassettes as necessary
Lead marker

METHOD

Place a loaded cassette on the tabletop face up Place the pad on the cassette ( ensure that the cassette is big enough to cover whole pad) Set a FFD of 100cm

Collimate to cover the pad

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

METHOD

Place the marker in one corner of the x-ray field ( note which corner of the pad it relates to) Set an exposure of 50kV and 6mAs

Expose
Process the film

EVALUATION

Look for radio opaque shadows within the pad

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

PATIENT POSITIONING AIDS

ACTION

If radiopaque shadows are detected, wash and dry the pad
Re – test

If opacities are still seen, replace the pad Continued use of the pad may be considered , provided it is identified as containing radiopaque material and not used where it might show on the films File a report

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

OTHER POSITIONING AIDS

PATIENT POSITIONING AIDS

A range of material can be used to assist in positioning the patient in specific positions, some radiolucent and some not Care should always be taken to ensure that radiopaque positioning aids do not obscure the image SANDBAGS:- These are radiopaque. They should have waterproof or removable cotton or linen covers that must be washed regularly FLOUR BAGS:- Similar to sandbags but are radiolucent. They mould to different shapes more readily, but are not so heavy as sandbags

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

OTHER POSITIONING AIDS

COMPRESSION BAND:- If the band is linen, detach from the end fixing mechanisms and wash as necessary If the band is plastic, simply wipe over with a damp cloth. The ratchet and fixing mechanisms should be inspected and tested six monthly or as necessary.

The band should also be tested every six moths or as necessary, for radiopaque substance contamination WATER BOTTLE:- Empty fixer or developer bottles full of water are useful as cassette supports, or in weight bearing views of a/c joints. Water is relatively radio –opaque. Little care is required, simply wipe the outside of the bottle with a damp cloth as necessary. Ensure that the lid is on tightly and that the bottle does not leak

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

OTHER POSITIONING AIDS

Polystyrene blocks used to pack equipment can be cut to required shapes
Polystyrene chips used in packing can be sealed into suitable sized cotton or linen bags
Cardboard boxes can be cut down to suitable sizes and shapes and re- stuck
Wooden blocks can be cut to shape

Folded blankets can also be useful

N/B It should be remembered that any improvised positioning aid checked as to its radiolucency before use

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY & Imaging – ACCESSORY EQUIPMENT

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

ACCURACY OF THE SCALE TEST

The aperture size scales on the collimator used be used to set the aperture size, so it is advisable to make sure that the scales are accurate Inaccuracy of scales may lead to inaccurate collimation

FREQUENCY OF TEST

6 monthly

EQUIPMENT REQUIRED

Collimator to be tested

100cm rule

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LIGHT BEAM / X-RAY BEAM ALIGNMENT TEST

The purpose of the light in a collimator is to allow more accurate collimation of the x-ray beam. The light must, therefore, coincide with the x-ray beam. The light beam relies on the accurate positioning of the light bulb and angled mirror inside the collimator Should either the mirror or light bulb be dislodged, then errors in collimation could occur, resulting in areas of interest being excluded from the field, or too large an area being irradiated

FREQUENCY OF TEST

6 monthly

As necessary

EQUIPMENT REQUIRED

One 24x 30 cm loaded cassette

Alignment test tool, commercially made test tools are available, but a simple alternative is to use eight coins or four paper clips Lead marker or ninth coin

METHOD

Make sure that the table is level and the central ray at 90° to the tabletop
Place a loaded cassette on the tabletop face up
Set a FFD of 100cm
Switch on the collimator light
Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

LIGHT BEAM / X-RAY BEAM ALIGNMENT TEST by:-

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

The purpose of the grid is to reduce the amount of scattered radiation reaching the film. Although the quality of the image is improved, it does mean a significant increase in exposure, and therefore dose to the patient.

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

GRID TYPES

STATIONARY

A loose grid which can be placed directly over the face of the cassette
The grid and cassette size must be the same
The grid ratio is usually 6: 1 or 8:1
Cassettes are available with a built in, or added grid

MOVING

A grid used in a potter Bucky system, which moves from side to side during the x-ray exposure, in order to defuse out the images of the lead strips The grid ratio is usually 10:1 or 12:1 The grid ratio should be 16: 1 if used for high kV work

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

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GRID

PARALLEL GRID

Lead strips run parallel to one another in one direction only
There are two types of parallel line grid, focused and non- focused

Moving and stationary grids are all of parallel construction

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

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GRID

CROSS – HATCH GRID

Two sets of lead strips superimposed and running at 90° to one another Generally a stationary grid, used only for relatively high kV work and when on tube angulation is necessary This design is used only in stationary grids

Quality Assurance and Quality Control IN DIAGNOSTIC RADIOGRAPHY

ACCESSORY EQUIPMENT

GRID

FOCUSED GRID

Focused grid has lead strips progressively incline more inward, the further they are from the centre line, so that they are focused to a pre – determined point above the grid Thin lead strips interspaced between equally thin strips of radiolucent material Covered top and bottom with thin Aluminium sheet