Level 3 Unit 306 – The safe use of ionising radiation to produce quality radiographic images Assignment Sample Answer

Unit 306 Aim

Enable you to develop the knowledge and skills needed to carry out your duties relating to dental radiography.  You will understand current legislation relating to radiography in addition to the principles and techniques of taking, processing, storing and quality assuring radiographs.  You will be able to demonstrate the processing methods used in your clinical environment.

Note: Do not copy and paste the information presented in this sample directly to your assignment. This is posted online, and it will easily get caught in plagiarism. If you are studying in the UK, you might know how strictly UK academic institutions are on academic integrity. This can fail or maybe restart the whole course.

306 - 1.1 - Describe the legal requirements for ionising radiation within a dental setting

Answer:

A. The current Ionising radiation regulations

The Ionising Radiation Regulations 2017, which are famously known as IRR17, are the statutory laws in the UK which control the use of ionising radiation in the workplace. They demand that any employer who operates X-ray equipment, as in the case of dental practices, has registered with the Health and Safety Executive (HSE) before operating machines and ensure that the radiation exposure to its staff and members of the general population is kept as low as reasonably practicable  (ALARP).

Risk assessment has to be carried out and documented, and employers are required to appoint qualified advisers inclduing a radiation protection adviser (RPA) and a radiation protection supervisor (RPS), to provide a safe working environment and compliance with regulations. IRR17 also brings in controlled areas and dose limits that should not ever be surpassed, and gives legal responsibilities that are related to the monitoring, training and safe systems of work. 

B. The current Ionising radiation (Medical exposure) regulations

Ionising radiation (Medical Exposure) regulations 2017 (IR(ME)R17) is aimed at safeguarding the health of the patient during medical ionising exposure, such as dental X-rays. These rules state that the justified exposure must be made to ensure the clinical benefit exceeds the risk, and the doses must be optimised in such a way that unnecessary radiation is minimised. They specify the legal obligation of the duty holders (employer, referrer, practitioner and operator) and mandate written procedures, like that of clinical audit, to guarantee patient safety. 

C. Local Rules

Written working procedures that are local to every dental practice site, and which define the manner in which ionising radiation will be safely utilised under IRR17, are known as local rules. They have to specify the controlled area, staff roles to be authorised, work instructions to limit exposure, contingency plans in the event of equipment failure or incidents and the name of the responsible radiation protection supervisor (RPS). Such regulations should be updated and easily available to employees. 

D. Radiation protection file

One of the documents stored by the employer to show that they are observing both IRR17 and IR(ME)R is the radiation protection file. Evidence that has been stored in it includes HSE registration certificate, local rules, risk assessments, staff training records, quality assurance results, inventory of X-ray equipemnt and audit records. Periodic assessment of the file is done to ensure that practice procedures are effective and satisfactory to the law. 

306 - 1.2 - Summarise the risks associated with ionising radiation.

Answer: 

A.  Primary Beam

The major beam is the direct X-ray beam that the dental X-ray unit generates. Since it is high-energy radiation that is being directed into the anatomy of the patient, there is direct exposure to the beam, which may result in the loss of cells and tissues, as well as tissue burns and a long-term effect like the development of cancer in case of over-exposure. The dental personnel should never be caught in the line of sight of the primary beam, and should keep a proper distance and covering between themselves and the beam so as to avoid the consequences. 

B.  Scatter radiation

When the main stream of X-ray is not absorbed by the patient or other contents, it strikes in other directions, and these are called the scatter radiation. This diffracted radiation is capable of indirect exposure to people or operators. Whereas doses are less than those in the primary beam, the cumulative radiation dose and possible health effects may arise due to repeated scatter exposure with time. 

C.  Absorption by the Patient

Radiation taken by the patient’s tissed may cause biological damage such as DNA damage, hieghtened chances of stochastic effects such as cancer, particularly in vital organs. The does absored is related to the risk and thus exposure should be minimised. 

D.  Equipment Failure

Defective X-ray devices can provide the patient and staff with both unnecessay radtions dose and unintended higher doses. Quality assurance and regular maintenance procedure can be used to avoid such failures. 

E. Incidental exposure (to the patient or to himself/herself)

Inadvertent exposure may happen, whereby operator error or procedural deficiency may result in unnecessary radiation doses. This risk can be minimised by being a strict partcipant in the safety measure and training. 

306 - 1.3 - What is the purpose of the controlled area?

Answer:

The controlled area is a defined area under the Ionising Radiations Regulations 2017 (IRR17) to safeguard the staff, patients and others against unnecessarily being exposed to ionising radiations during dental X-ray procedures. Its primary aim is to provide proper control and limitation of exposure to radiation through the explicit specification of the areas where special safety measures are required and those where access is limited whenever the X-ray equipment is in operation.

The identification of controlled areas is based on a radiation risk assessment and could be limited to the entire room where the X-ray machine is located or a specified distance (such as within 1.5 m of the X-ray tube and patient) in which the primary beam and scatter will most probably lead to exposures exceeding the background levels.

The designation of such an area assists the staff in knowing when they should adhere to the elaborate Local Rules and stay out of the area during exposures, and avoid unapproved entry that may result in inadvertent exposure. Even trained personnel are only allowed to enter under written arrangements, except those who are needed in the procedure, and the patients who have gone through the exposure may be allowed in. Dangerous zones can also be signalled and, where possible, be delineated physically to present boundaries. The measures assist in maintaining a radiation dose as low as reasonably practicable (ALARP) and meet the legal safety standards.

306 - 1.4 - What is the importance of an isolation switch?

Answers: 

An isolation switch (also known as a mains isolator) is an important safety measure in dental radiography rooms that permits the entire de-energising of the X-ray equipment and its electrical power source in an emergency. Under the safe use of the dental X-ray equipment, control panels, exposure switches and mains isolation switches must be located outside the controlled area so that they can be accessed without entering the radiation zone when the equipment is turned on.

This will make sure that when there is a problem like an electrical fault, suspected equipment malfunctioning, fire hazards or other unsafe factors, the operator or other trained individual will be able to swiftly and safely deactivate the X-ray machine and avoid any additional radiation being released. 

Having the isolator in a place not under the controlled area also minimises the efforts of re-entering a hazardous area by personnel to switch off equipment to ensure that occupational exposures remain at levels as low as reasonably practicable. This is in accordance with the lawful responsibilities of the Ionising Radiations Regulations of having safe work systems and emergency procedures.

The isolation switch should also be properly maintained by regular inspection to ensure that it works correctly, which is a component of the radiation protection and safety systems of the practice.

306 - 1.5 - What is the purpose of lead foil in a traditional radiographic film?

Answer:

In conventional dental X-rays, a sheet of thin lead foil is put behind the film to absorb the scattered and remaining X-rays that pass through the patient and the film. Unless the radiation is absorbed, this back-scatter radiation may penetrate the film at the rear, which in effect smears the film and causes a loss of image contrast and diagnostic quality.

The lead foil also captures part of the radiation that otherwise passes into the tissues of the patient to aid in a slight reduction of patient dose. Also, when the film packet is inverted, the embossed pattern on the foil is visible on the radiograph, which shows a mismatch.

306 - 1.6 - What is the purpose of an intensifying screen in an extra-oral cassette?

Answer:

The purpose of an intensifying screen in an extra-oral cassette is to convert X-ray energy into visible light; due to this process, the film that is captured is exposed more efficiently compared to X-rays. X-rays basically sends phospher crystals on screen, then it fluresce and emit light, which exposes the image on both sides, resulting in an image that has less radiation compared to when it is directly exposed to X-rays.

This is beneficial as it decreases the dose of radiation on the patient, which improves the safety while producing a diagnostic image in panoramic and cephalometric radiography. 

306 – 2.1 - Explain the diagnostic value of intra-oral radiographic images.

Answer:

A.  Bitewing Radiographs

A bitewing radiograph is a form of intra-oral radiographic picture, which is mainly used to diagnose dental conditions, including alveolar bone and tooth crown conditions. They come in handy, especially when there is a need to:

• The caries (tooth decay) are particularly the interproximal caries that cannot be detected during a clinical examination.
• Determining the extent of bone in the alveoli in periodontal disease.
• Assessing the quality of old restorations and crowns.

B. Periapical Radiographs
The periapical radiographs are a whole tooth image, which is a view of the crown and the tip of the root with the surrounding bone structure. They are essential for:

• Abscesses or cysts are apical pathology.
• Assessment of pre and post endodontic root canal anatomy.
• Evaluation of affected teeth, planning of implant before care, and after care evaluation.

306 – 2.2 – Explain the diagnostic value of extra-oral radiographic images.

Answer:

A.Dental pantomograph (DPT) / orthopantomograph (OPG) / panoral

Dental Pantomograph (DPT) / Orthopantomograph (OPG) / Panoral.
They are forms of extra-oral radiographic images which give a panoramic view of the entire mouth, with all the teeth in the upper and lower jaw present on one image.

They are valuable for:

• Examination of the affected tooth, including wisdom teeth.
• The diagnosis of fractures of the jaw and bony lesions.
• Orthodontic treatment planning.
• Detecting sinus pathology.
• Screening for oral cancer.

306 - 2.3 - Evaluate the advantages of using digital radiography in the dental setting.

Answer:

Digital radiography in the dentistry field can provide remarkable clinical, safety and operational benefits over the traditional film-based X-rays. One of the greatest advantages is that it is associated with less radiation exposure; digital systems normally use up to 70-90 per cent less radiation, which reduces the risks to patients and enables the dental practices to adhere to the principle of safety, including ALARA (as low as reasonably achievable).

Digital radiography also offers immediate availability of the image. Photos are displayed on the screen of a computer as soon as they are exposed, which removes the delay of film processing, and allows a dentist to make fast diagnoses and converse with a patient on the diagnosis they made during the same visit. The capability of improving and editing images, such as changing the brightness, contrast and magnification, is seen to improve the accuracy of a diagnosis because fine problems, such as their existence at an early age, bone loss or root pathology can be easily identified.

Operationally, digital images can be stored with ease, are readily accessed and shared electronically, and thus do not require the use of physical storage space, and communication of referrals with specialists or insurers becomes simple. Environmental benefits are also in place, because the digital systems will not require chemical treatment and disposal of the film related to traditional X-rays.

In general, digital radiography can contribute to patient safety, diagnostic competence, and improve clinical practice in the field of dentistry.

306 – 3.1 – Explain the methods of processing radiographs.

Answer:

Techniques of Radiographic Processing.

A.  Automatic Film Processing

This technique uses an automatic film processor. The film is loaded into the machine, whereby the film is automatically processed by a series of processes, which include developing, fixing, washing, and drying.
 
B.  Digital Processing

Digital processing is a process of digitising the analogue information that is in the film and can be viewed on a computer. There are two types:

a). Direct Digital Processing: This technique involves the direct capture of the radiographic image by a sensor, which subsequently converts this image into a digital format.

b). Incidental Digital Processing: This technique is based on a phosphor plate, which records the radiographic image. The plate is then scanned with a special scanner, which transforms the picture into a digital form.

306 – 3.2 – Describe the reasons for faults visible on radiographic images.

A.    Operator error    
B.    Processing error    
C.    Patient error and accessories (e.g., dentures, glasses)    
D.    Equipment error     
E.    Storage of materials     

Answer:

A. Operator Error: This may involve improper positioning of the patient or the X-ray machine, improper exposure setting or improper manipulation of the film.

B. Processing Error: This may happen when the chemicals being processed are out of date or are contaminated or the film is not processed appropriately.

C. Patient Misjudgment and Accessories: This may involve movement at the time of exposure, or artifacts produced by any other assistance like dentures or glasses.

D.  Equipment Error: This may involve defects on the X-ray machine itself, like wrong radiation dispensation.

E. Storage of Materials: Movies or chemicals may be destroyed as a result of improper storage and hence the radiographic image may be of poor quality.

306 - 4.1 - Describe the quality control systems used in dental radiography.

Answer:

Dental radiography quality control regimes are needed to make sure that the X-ray images are diagnostic, safe and legal/professional attainable. Quality control is included within a larger quality assurance (QA) programme that facilitates a reduction in repeats, the preservation of image clarity, and the reduction of radiation dose to patients and personnel. Regular testing and monitoring assist in getting any equipment failures, processing problems and image-quality issues early, so that corrective action can be provided.

The regular testing of equipment is one of the major quality control systems. Dental x-ray machines should be periodically inspected regularly on mechanical stability, output consistency, proper collimation, tubehead drift, timer accuracy and exposure reproducibility. These tests contribute to safe operation and constant image quality with time.

Quality control checks also should be done daily before clinical usage, such as warm-up procedures, meter-working, testing equipment and equipment integrity checks. This will make sure that the system works well even before any exposure to a patient.

In the film-based systems, the quality control involves fresh film tests, step-wedge tests and control of the film processing conditions in terms of chemical content, temperature and processing time. These precautions avoid fogging and defects of the image.

In the case of digital systems, the quality control is the control of sensor performance, image display verification and software validation in order to preserve diagnostic quality. These tests are being improved on a sustained basis through comprehensive recording and auditing of such tests. 

306 - 4.2 - Explain how the following quality control systems are carried out to comply with the ALARP principle (radiation dose to be As Low As Reasonably Practicable).

Answer:

A.    Radiographic image grading process    
B.    Step-wedge test    
C.    Quality assurance of direct and indirect digital X-ray sensors/plates    
D.    IRMER operator requirements    

There is quality control, which is done based on the principle of ALARP (As Low As Reasonably Practicable). This involves:

A.  Process of Radiographic Image Grading: This is done by analyzing the standard of the radiographic image and detecting the presence of fault or error.

B. Step-Wedge Test: This test is applied to test the performance of X-ray machine and the processing system.

C. Direct and indirect Digital X-ray Sensors/Plates Quality Assurance: This will include routine validation and calibration of the sensors or plates so as to confirm that they are properly operating.

D. Operator Requirements IRMER: The operators should be trained and competent in operating the equipment and they should behave in accordance with the requirements as provided in the Ionising Radiation (Medical Exposure) Regulations (IRMER).

E. The Nailing of Radiographic pictures: The radiographic images are normally placed on a light box or a digital viewing screen. The pictures must have the correct orientation left side of the patient to the left of the viewer. The radiographs must be marked with the name of the patient, date when the radiograph was taken and any other prudent details.