5: Radiology

CHAPTER 5 Radiology

FUNDAMENTAL RADIATION PHYSICS

Understanding radiation physics requires a basic knowledge of atomic structure, radiation types, properties of radiation.

B. Types of radiation: particulate and electromagnetic radiation are types of ionizing radiation:

X-Ray Machine and Components

X-ray machine has basic operable components and internal components that are important for safe operation and functioning.

B. Internal components: include x-ray tube, power supply, circuit, transformer:

Generation of X-Rays

X-rays are produced in x-ray tube through complex process that involves negative and positive poles and differing types of x-rays produced.

Factors That Determine Radiation Injury

Several factors determine amount of injury that occurs from radiation: total dose, amount of area exposed, types of cells exposed, cell sensitivity.

Radiation Protection

Proper use of equipment, patient and clinician positioning, and technique can provide acceptable limits to incidental radiation exposure. Advances in dental radiograph technology have reduced scatter radiation, the reason for protective boxes; lead-lined radiograph storage boxes are thus unnecessary and should be discarded, since they contaminated the film. There is controversy over need for lead (or lead equivalent) aprons for patient protection. Note that term “clinician” is used for operator.

A. Patient: patient exposure to radiation MUST BE reduced by using filtration, collimation, positioning, shielding:

B. Clinician: measures MUST be taken to protect clinician from unnecessary radiation; include proper positioning, use of monitors, attention to proper methods of taking radiographs:

2. Monitoring:

CLINICAL STUDY

Age 42 YRS SCENARIO
Sex image Male imageFemale The new patient’s intraoral examination reveals several suspect areas and fractured restorations on the maxillary arch. It has been at least 6 or 7 years since patient has had radiographs taken. The dental hygienist recommends a full-mouth series (FMX). However, the patient is reluctant because of what she has heard about the dangers and misuse of radiation.
Height 5′4″
Weight 170 LBS
BP 118/76
Chief Complaint “Boy, the fillings in my upper back teeth are so sensitive! They feel like they are moving when I bite down.”
Medical History

Current Medications None Social History

CHARACTERISTICS OF RADIATION IMAGES

Radiation images are characterized by their quantity, quality, intensity, clarity.

RADIOGRAPHIC EXAMINATION

Radiographic examination involves intraoral, extraoral, and special imaging techniques to produce high-quality radiographs for use in examination, interpretation, diagnosis of dental conditions and diseases. (See the CD-ROM image for WebLink to the ADA/FDA Guide to Patient Selection for Dental Radiographs, which includes the chart Guidelines for Prescribing Dental Radiographs.) These guidelines will allow for ALARA concept, although each case is subject to clinical judgment.

Intraoral Techniques

Intraoral radiography includes bisecting, paralleling, and occlusal techniques.

Jan 1, 2015 | Posted by in Dental Hygiene | Comments Off on 5: Radiology
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