Radiographic Technique

RADIOGRAPHIC TECHNIQUE

Basic principles of radiography, terms and definitions

Objectives

• At the end of this module the students should be able to

DEFINE

• Radiography
• radiographic technique
• Radiographic procedures
• Medical radiology
• Radiologist
• Radiographer

Radiograph

1.Radiography

• Is a science of utilizing radiation
• Radio-referring to radiation and Graph referring to record making.
• Radiography is therefore the science of making record by means of radiation
• This study is divided into two branches;
• Medical radiography

Industrial radiography

1.Medical radiography has two branches these are;1; diagnostic radiography(diagnostic)

• 2;therapy radiography (treatment)
• Industrial radiography
• This specifically for industrial purposes
• Other applications of radiation are for
• Security i.e. in the airports and customs

Research production centers

Radiographic Technique

2.Radiographic technique ;is a procedure where by radiographic film is exposed to a controlled amount of x ray in order to produce anatomical set up to any part of the human body for diagnostic purposes.

The normal radiographic anatomy is the same for all human beings .the normal radiograph of part of people must be identical

Radiographic Technique

3 .Radiographic procedure; is a way or method used by radiographer to obtain a diagnostic radiograph. As from the time receiving patient, prepared examined and after care.

• 4.Medical radiology(imaging)

The application of sciences of X -ray, ultrasound, MRI,CT to diagnose disease 5.Radiologist;is a medical doctor whose specialist qualification is based in medical imaging

6.Radiographer is a person train in radiography he /she is skilled in performing radiographic procedures

• He/she is the one assisting the radiologist in medical imaging
• Radiograph is a visual image produced by x rays on a piece of photographic materials

Terminology applicable to radiography

In radiographic technique you have to know some common descriptive terms which determine the way a patient is positioned in relation to the film and source of x rays In anatomy and in radiographic technique the human body is described in anatomical position

Radiographic Technique

Anatomical position this is standard position where by the person is in erect ( standing) such that a part ie when the body is straight the eyes and face directed foward, hands supinated by side o trunk and heels together, feet point forward Aspect indicates a surface view of subject under examination

Anterior aspect: that seen when viewing the patient from the front.

Posterior (dorsal) aspect: that seen when viewing the patient from the back.

Lateral aspect: refers to any view of the patient from the side. The side of the head would therefore be the lateral aspect of the cranium.

Medial aspect: refers to the side of a body part closest to the midline, e.g. the inner side of a limb is the medial aspect of that limb.

Superior top or the upper part

• Inferior lower part
• Cephalic towards the head
• Caudad toward the feet
• Proximal near the trunk

Distal away from the trunk

Planes of the body

Three planes of the body are used extensively for descriptions of positioning both in plain-film imaging and in cross-sectional imaging techniques.

Median sagittal plane: divides the body into right and left halves. Any plane that is parallel to this but divides the body into unequal right and left portions is known simply as a sagittal plane or parasagittal plane.

Planes of the body……

• Coronal plane: divides the body into an anterior part and a posterior part

Transverse or axial plane: divides the body into a superior part and an inferior part.

PROJECTION/VIEWS APPLIED IN RADIOGRAPHY

A projection is described by the direction of the central ray relative to aspects and planes of the body.

Refers to various positions patient is placed for examinations in relation to radiation source and recording medium

Basic view(or routine)

• These are views (projections) which give best information as pertaining disease or injury
• They are international
• Alternative view
• Projection which are done when isnt possible to do basic view
• Supplementary view
• This projection locates some diseases which can not clearly seen on the basic views.

They remove some doubts

Antero-posterior (A.P)

The central ray is incident on the anterior aspect, passes along or parallel to the median sagittal plane, and emerges from the posterior aspect of the body.

Postero-anterior (P.A)

The central ray is incident on the posterior aspect, passes along or parallel to the median sagittal plane, and emerges from the anterior aspect of the body.

Lateral (Lt or Rt)

The central ray passes from one side of the body to the other along a coronal and transverse plane.

Oblique

The central ray passes through the body along a transverse plane at some angle between the median sagittal and coronal planes.

Anterior oblique

The central ray enters the posterior aspect, passes along a transverse plane at some angle to the median sagittal plane, and emerges from the anterior aspect.

Posterior oblique

The central ray enters the anterior aspect, passes along a transverse plane at some angle to the median sagittal plane, and emerges from the posterior aspect.

Centering point(cp) these locate on the body where the central ray will pass

Central ray the ray imagined to be in the center of the x tray beam Focal film distance(ffd) distance between the x ray source and the film ,the standard FFD Is 100 cm Kilovoltage penetrating power of x rays(quality) Milliampere quantity of x rays

• Seconds exposure time

Milliampere seconds stands for a quantity if x ray exposed at certain (given) time

PROCEDURES OF RADIOGRAPHY

These are procedures carried on from time receiving the request form until the time patient leaving the x-ray room after completing examination also known as radiographic drill They are grouped in four categories:

• Preparation for the examination

Introduction to the patient

• During examination

After care (after examination)

Preparation for the examination

• read and understand the request form

collect all necessary accessories e.g. sand bag, films, anatomical marker Prepare room to receive patient e.g x ray tube should be ready for that particular examination Tabulation of exposure factors

Identify the patient:

• -By name and title if is Mr. or Prof, Dr, etc
• By examination e.g chest
• -Greet and give brief explanation as pertaining examination

assist patient to the changing cubical -Prepare the patient psychological, physical and physiological this can either be short term preparation or long term e.g in IVU,barium examination etc.

• -Assisting patient to the examination room
• –

2.Introduction to the patient

3. During examination

• -Correct size of cassette with anatomical marker, foam pads etc.
• -Positioning of the patient
• -Centre the x ray tube

-Instruction of breathing and practice

3.After care (after examination)

• -if patient had hold breath tell him to breath normal
• -Assist patient out of x ray room to changing cubical and then waiting area

-Process the film and check radiograph -Return the accessories into original place. Room should be ready to receive another patient -Radiograph should be given to the patient or sent to the radiologist for reporting] Patient’s property, privacy is under care of radiographer

IDENTIFICATION OF RADIOGRAPH:

Details of each radiograph must include by which it can be associated with a particular patient.

Surname and initials of the patient in i.e enable the interpreter to identify the owner of the radiograph.

• The date on which the film was taken:

Important mostly in follow up films.

An indication of the left or right sides of the patient i.e help to know the particular part.

FILM CRITIQUE:

Each radiograph should be taken with the following points in mind.

The film size must be correct: It must include the part to be demonstrated without being too large.

All limb radiographs must include at least one joint as a guide to the position and alignment of fracture fragments.

• The position must be standard.
• The image definition must be adequate
• There should be some evidence on he film that the primary x-ray beam has been limited.
• Unnecessary artefacts should not appear on a radiograph.

All details of identification should be present and accurate.

B: In the x-ray room there are four things which can be moved:

• X-ray tube
• X-ray table
• Cassette
• Patient

The patient should be moved as a best resort.

FACTORS WHICH AFFECT SELECTION OF OPTIMUM EXPOSURE FACTORS ARE:

• Age of the patient – old patients have degenerated bones.
• Nutritional status of the patient.
• Occupation:
• Collies have stronger chest and arm muscle.
• Over used and under used limbs or paralyzed limbs
• Limbs in P.O.P wet or dry.
• Collimated views.
• Ability to keep still.

Photographic factor, films/ screens and processing chemicals, temperature of chemicals.

The standard viewing of film (presentation of radiographs):

• All radiographs are viewed in a standard manner (an anatomical position).
• Exceptions to the standard viewing are:
• Hands and wrist are viewed from the posterior aspect with fingers upper most.
• Toes and feet are viewed from the dorsal aspect with the toes upper most.
• Lateral chest films are viewed from the film aspect.

G

general principles of radiography of the skeletal system:

• Two views should be taken at right angles to each other.
• This is to complete a part under examination.
• At least one joint should be included.

The less painful or the easiest view should be taken first.

Indications for radiography of the skeletal systems:

• Pathological conditions i.e. congenital deformities, neoplasm diseases etc.

Traumatology cases i.e. fracture, subluxation, dislocation.

Forensic cases identification of individual, support the establishment the cause of injury of death.

• Age assessment.

Foreign bodies localization.

RADIATION PROTECTION:

• The main features of dose limitation are:
• Ionizing radiation shall not be used if there is any other way of
• achieving the require result
• All exposure shall be kept as low as reasonably achievable,
• this is known as the ALARA.
• The dose equivalent to individual shall not exceed the limits
• recommended by international

commission for radiological protection (ICRP).

There are three main purposes to minimize the radiation dose received by both patient, staff and public.

To reduce the gonad dose to the general population. This is the genetic effect (gonad mutations) i.e. it is observed only in the descendants of those irradiated.

To protect tissues those are particularly susceptible to damage by irradiation. Effect observable in the individual irradiated are somatic effects.

To ensure that the radiation dose received by staff working in radiology departments is kept at a level at which it is of negligible significance – ALARA principle.

TO STAFF:

• Never stand in the direct beam.
• Collimate the beam accurately to reduce the area irradiated.

Never support or hold patients during radiography.

Always stand behind the lead protective screen around the control panel if not possible a lead apron must be worn.

Protective coats, aprons, gloves and gonad shields should be cheeked for cracks.

TO PATIENT:

Collimating – x-ray beam should be directed only to the area of interest.

Short exposure time-patient should be subjected to the x-ray beam for short possible time.

Proper explanation to patient help to achieve maximum co-cooperation hence avoiding unnecessary repetition of radiographs.

• Primary beam should not be directed to gonads.
• Patient should not sit direct on the line of primary beam.
• Positive identification of the patient and proper understanding of the request form.

TO PUBLIC:

• Should leave the room while the exposure is being made.

When there is a need to support patient, a lead apron should be worn