ST.JUDE COLLEGE – CAVITE

URC – Ave. Salitran IV, Dasmarinas City, Cavite 4115

QUALITY CONTROL OF SCATTERED RADIATION IN SELECTIVE HOSPITAL IN

CAVITE

A Research Thesis

Presented to

The Faculty of School of Radiologic Technology

St. Jude College – Dasmarinas City, Cavite

In Partial Fulfillment Of the Requirement for the Degree

Bachelor of Science in Radiologic Technology

By:

Carl Jason A. Cruz

SY: 2013 – 2014

APPROVAL SHEET

This thesis here to entitled:

QUALITY CONTROL OF SCATTERED RADIATION IN SELECTIVE HOSPITAL IN

CAVITE

Prepared and submitted by Carl Jason A, Cruz in partial fulfillment of the requirement

for the degree of Bachelor of Science Major in Radiologic Technology has been

examined and is recommended for acceptance and approval for Oral Defense.

____________________________________

VIVIAN S, BLANCO, DMD, RN , MAN

Adviser

Approval in partial fulfillment of the requirement’s for the subject ELEMENT OF

RESEARCH by the Committee of Oral Examination with the grade of ______________

___________________ ________________________

MEMBER MEMBER

___________________________________

Date

ACKNOWLEDGEMENT

With profound gratitude, the researchers wish to extend their utmost appreciation

to the following.

The Radiologic Technology Students of different school and Hospital Staff or the

Registered Radiologic Technology who have their knowledge and expertise on the said

study.

Ms. Vivian S, Blanco, DMD, RN ,MAN, for her sincere and valuable assistance in

the formation of the study and throughtout its development. Her wisdom of intruction

and discussion of information beaceme an opening torch, hence a flame which triggered

this research to make this thesis a reality.

We would like to Acknowledge and extend our heartfelt gratitude to the following

Panelist

______________________________________________________________________

__________________________________________________ who give time and effort

to listen us and was so kind to lend the books and other material needed in pursuing

this study.

Most especially to our family, friends words alone cannot express what we owe

them for their encouragemnt and whose patient, love enabled us to complete this

Research. And us for going the extra mile with the kind of feedback that put flesh on the

bones.

Above all, to the Divine Almighty God the Father in Heaven who continously

supplies this researcher the spiritual and material needs the made him strong and

determined to pursue this study.

THESIS ABSTRACT

Thesis Tittle : QUALITY CONTROL OF SCATTERED

RADIATION IN SELECTED HOSPITAL IN CAVITE

Researcher : Carl Jason A, Cruz

Number of Pages :

Degree Conferred : Bachelor of Science in Radiologic Technology

Name/Address of Institution : St. Jude College – Cavite URC Ave. Salitran IV

Dasmariñas City, Cavite

Date Started : November 2013

Date Completed : March 2014

TABLE OF CONTENTS

TITTLE PAGES

APPROVAL SHEET

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENTS

CHAPTER

1. PROBLEM AND IT’S BACKGROUND

Introduction

Statement of the Problem

Hypothesis of the Study

Scope and Delimitation of the Study

Conceptual Framework

Significance of the Study

Definition of Term

2. REVIEW OF RELATED LITERATURE

Foreign Studies

Synthesis

3. METHODOLOGY

Research Design

Data Gathering Instrument

Data Gathering Procedure

Statistical Data

4. PRESENTATION, ANALYSIS AND INTEPRETATION OF THE DATA

Specific Problem No. 1

Specific Problem No.2

Specific Problem No. 3

5. SUMMARY AND CONCLUSION AND RECOMMEDTIONS

Summary of Findings

Conclusion

Recommendation

REFERENCES

A. BOOK

APPENDICES

A. Letter of Request

B. Letter to the Respondents

C. Letter of Validation

D. Questionnaires

CURRICULUM VITAE

CHAPTER 1

THE PROBLEM AND ITS SETTING

INTRODUCTION

Radiographer must conscientiously avoid unnecessary radiation exposure as

well as strive to keep patient dose to an absolute minimum. Radiographer must follow

the ALARA Principle (As low as reasonably achievable) as they carry out their tasks.

The Radiologic facility must undergo appropriate Radiation surveys. Staff must be

proper oriented and regular in service education on radiation safety must take Place.

Proper radiation monitoring and review of monthly radiation report is essential

According to (Dorothy A. Saia - 2008) Occupational Radiation sources

(A) Scattered radiation is when primary photon intercept an object and undergo a

change in direction.

(B) Grid both stationary and moving, function to remove a large percentage of

scattered (primary Compton) radiation from the remnant beam before it reaches the

image receptor, thereby improving radiographic contrast, But necessitate an

increase in exposure.

The most significant occupational radiation hazard in diagnostic radiology is

scattered radiation from the patient, particularly in fluoroscopy, where the use of high

voltage results in energetic Compton Scattering emerging from the patient and posing a

real occupational hazard to radiologist and radiographer. The intensity of Scattered

Radiation one meter from the patient is about 0.1% of the intensity of the primary beam.

That is why in term of radiation protection the patient is considered the most important

source of scatter. Other Scattering object include the x-ray table. The bucky-slot cover/

closer and the control – booth wall.

According to Stewart C Bushong (2009) Production of Scatter Radiation

two types of x-rays are responsible for the optical density and contrast on a radiograph

those that pass through the patient without interacting and those that are scattered

within the patient through Compton interaction X-ray that exist from the patient are

remnant x-ray and those that exit and interact with the image receptor are called image-

forming x-rays.

Proper collimation of the x-ray beam has the primary effect of reducing patient

dose by restricting the volume of irradiated tissue. Proper collimation also improve

image contrast. Ideally, only those x-rays that do not interact with the patient should

reach the image receptor.

As scattered radiation increase the radiograph loses contrast and appears grey

and dull. Three primary factors influence the relative intensity of scatter radiation that

reaches the image receptor: Kvp, field size, and patient thickness.

Control of scatter radiation , effect of scatter radiation on image control

One of most important characteristic of image quality is contrast, the visible different

between the light and dark areas of an image contrast is the degree of difference in OD

between areas of radiographic image. Contrast resolution is the ability to image and

distinguish soft tissue. Even under the most favourable condition, must remnant x-ray

are scattered.

Scatter Radiation Control

The radiographer must strive to minimize the quantity of

scatter that reaches the IR

Restrict the x-ray beam size to the size of the anatomical

structures required to demonstrate in the image

No reason to leave collimators open to extend beyond

the IR size

Objective is to decrease patient radiation dose, and

achieve optimum contrast.

Statement of the Problem:

The main emphasis of this research is to determine the Quality Control of

Scattered Radiation and keep patient dose to an absolute minimum. Specifically this

research study to answer the following question:

1. What is the most important beam restriction to reduce the production of scattered

radiation and why?

2. What is the risk and benefits of using Grid in radiographic examination?

3. What is the purpose of air gap technique in decreasing the amount of scattered

radiation reaching the film?

4. What are some method of achieving the ALARA goal?

Hypothesis

1. Collimation is the most important way to reduce patient dose. The collimator

is over all, the most efficient beam restricting device. It is attached to the tube

head, and its upper aperture, the first set shutters, is placed as close as

possible to the x-ray tubes port window. This is done to control the amount of

image degrading “off-focus “ radiation .

2. Grid both stationary and moving, function to remove a large percentage of

scattered (primary Compton) radiation from the remnant beam before it

reaches the image receptor, thereby improving radiographic contrast, But

necessitate an increase in exposure.

3. An air gap technique may be used to function similarly to , or in place of, a

grid. A distance is introduced between the patient and the film. Scattered

photons emerging from the patient will continue to diverge and never reach

the film.

4. Radiographers must follow the ALARA principle as they carry out their task.

The radiologic surveys staff must be properly oriented and regular in service

education or radiation safety must take place.

Scope and Delimitation

This research will cover the Quality Control of Scattered Radiation in our patient

and ourselves to an absolute minimum.

This chapter represent, as description of the method of research used,

respondent of the study, instrumentation and analysis of data and will be finish by the

second semester school year 2013 – 20014

In the event of this scholarly study, the researchers will use a descriptive method.

Employing the substantial procedure and activities performed will help validate the

findings of this present study.

Definition of terms:

Aperture diaphragm – simple beam restricting device that attaches a led-lined metal

diaphragm to the head of the x-ray tube.

Air-Gap technique – Practice of moving the image receptor 10 to 15 cm from the patient

so that fewer scattered x-rays interact with the image receptor, thereby

enhancing contrast.

ALARA – Principle that states radiation exposure should be kept As Low As Reasonably

Achievable, when economic and social factor are taken into account.

Artifact – false features of an image caused by patient instability or equipment

deficiencies.

Beam restrictor – Device that restricts the size of the x-ray field to only the anatomic

structure of interest.

Collimation – Restriction of the useful x-ray beam to reduce patient dose and improve

image contrast.

Collimator – Device used to restrict x-ray beam size and shape.

Cones and cylinders – Modification of the aperture diaphragm .

Grid – Is a device interposed between the patient and image receptor and absorb a

large percentage of Scattered Radiation.

Kvp – A measure of the maximum electrical potential across an x-ray tube; expressed in

kilovolts.

Optical Density (OD) – The distance from the image receptor to the object that is to be

imaged.

Radiation – The energy emitted and transferred through matter.

Radiography – The process and procedure of producing a radiograph

Scattered Radiation - Scattered radiation is when primary photon intercept an object

and undergo a change in direction.

.

Conceptual framework

The conceptual framework of the study presented in the paradigm used the

input- process system model.

The input Section include the Beam restricting device, the use of grid , the

purpose of air gap technique and the method of Achieving the ALARA goal.

the input was identified through questionnaires to be conducted by the

researcher’s. Such process was facilitated through gathering of information from the

respondents. The process include organization of data and analysis.

The output show the organized data and its implications. It present the plan or

recommendation for the radiologic technology students.

INPUT

1. What is the most important beam restriction to reduce the production of scattered radiation and why?

2. What is the risk and benefits of using Grid in radiographic examination?

3. What is the purpose of air gap technique in decreasing the amount of scattered radiation reaching the film?

4. What are some method of achieving the ALARA goal?

OUTPUT

Collimation is the most important way to reduce patient dose, grid are used to remove a large percentage of scattered radiation from the remnant beam before it reaches the image receptor. Air gap technique may be used to diverge the scattered and never reach the film. The radiologic surveys staff must be properly oriented and regular in service education or radiation safety must take place.

Implementation of seminar for Quality Control of Scattered Radiation

PROCESSResearcher made

questionnaire

Significance of the Study

The findings of this study will be beneficial to student, teachers, registered

radiologic technologist and school authorities.

To the radiologic technology student – the study give the student an idea on how

to control the production of scattered radiation and avoid unnecessary radiation

exposure to themselves as well strive to keep patient dose to an absolute minimum.

To the Future Researchers – this will actively motivate the future researchers to

take additional studies involving this research the quality control of scattered radiation in

radiographic procedures.

To the College Faculty of Radiologic Technology – this will serve as an additional

lecture material and presentation of the course subject.

Chapter 2

REVIEW OF RELATED LITERATURE

A. Related literature

This Chapter contains a review of related literature and studies which have

bearing on the present study. These related readings taken from material are very

necessary in coming up with comprehensive research.

Radiographer must conscientiously avoid unnecessary radiation exposure as

well as strive to keep patient dose to an absolute minimum. Radiographer must follow

the ALARA Principle (As low as reasonably achievable) as they carry out their tasks.

The Radiologic facility must undergo appropriate Radiation surveys. Staff must be

proper oriented and regular in service education on radiation safety must take Place.

Proper radiation monitoring and review of monthly radiation report is essential

According to Dorothy A. Saia (2008) Occupational Radiation sources (A)

Scattered radiation is when primary photon intercept an object and undergo a change in

direction.

The must significant occupational radiation hazard in diagnostic radiology is

scattered radiation from the patient , particularly in fluoroscopy , where the use of high

voltage results in energetic Compton Scattering emerging from the patient and posing a

real occupational hazard to radiologist and radiographer. The intensity of Scattered

Radiation one meter from the patient is about 0.1% of the intensity of the primary beam.

That is why in term of radiation protection the patient is considered the most important

source of scatter. Other Scattering object include the x-ray table. The bucky-slot cover/

closer and the control – booth wall.

Leakage radiation is that which is emitted from the x-ray tube housing in direction

other than that of the primary beam.

According to Stewart C Bushong (2009) Production of Scatter Radiation two

types of x-rays are responsible for the optical density and contrast on a radiograph

those that pass through the patient without interacting and those that are scattered

within the patient through Compton interaction X-ray that exist from the patient are

remnant x-ray and those that exit and interact with the image receptor are called image-

forming x-rays.

Proper collimation of the x-ray beam has the primary effect of reducing patient

dose by restricting the volume of irradiated tissue. Proper collimation also improve

image contrast. Ideally , only those x-rays that do not interact with the patient should

reach the image receptor.

As scattered radiation increase the radiograph loses contrast and appears grey

and dull. Three primary factors influence the relative intensity of scatter radiation that

reaches the image receptor: Kvp, field size, and patient thickness.

One of most important characteristic of image quality is contrast , the visible

different between the light and dark areas of an image contrast is the degree of

difference in OD between areas of radiographic image. Contrast resolution is the ability

to image and distinguish soft tissue. Even under the most favorable condition, must

remnant x-ray are scattered.

According to (Dorothy A. Saia ) BEAM RESTRICTION, or limitation of field size,

is probably the single most important factor in keeping patient dose to a minimum. The

primary beam must be confined to the area of interest, thus, only tissues of diagnostic

interest will be irradiated.

- Benefit of beam restriction is that, because a smaller quantity of

tissue is irradiated, less scattered radiation will be produced.

- Remember , scattered radiation does not carry useful

information; it degrades the radiographic image by adding a

layer of fog that impairs image visibility.

THREE BASIC TYPE OF BEAM RESTRICTOR , APERTURE DIAPHRAGMS, CONES,

AND COLLIMATION.

Aperture diaphragm

Aperture diaphragm is the most elementary of the three types, and is

frequently used in dedicated-head units and many of today’s dedicated-

chest units. It is simply a flat piece of lead (Pb) with a central opening

whose size and shape determines the size and shape of the x-ray beam.

Whereas head units have a variety of aperture diaphragm sizes available

for various type of skull exams and required film sizes.

Cones and cylinder

Cones are circular, lead-lined devices that slide into place in the tube

head. They may be the straight cylinder type, whose proximal and distal

diameter are identical, or the infrequently used flare type, whose distal

diameter is greater than its proximal diameter. Cylinder cones are

frequently able to extend, like a telescope, by means of a simple thumb

screw adjustment.

Collimation

The collimator is , overall, the most efficient beam – restricting device it is

attached to the tube head, and its upper aperture, the first set of shutters,

is placed as close as possible to the x-ray tube’s port window.

This is done to control the amount of image degrading “off-focus” radiation

leaving the x-ray tube. ie, radiation produced when electrons strike anode

surfaces other than the focal track.

The next set of lead shutters ( or “blades,” or “leaves”) actually

consists of two pairs of adjustable shutters- one pair for field length and

other pair for field width. It is these shutters that the radiographer adjusts

when changing the field size and shape.

B. Related studies

(Bushong, 2008).In order to reduce radiation exposure it is necessary to

decrease the area of the x-ray beam. Proper beam restriction will reduce the amount of

primary photons emitted from the tube and collimator thereby reducing the dose to the

patient. Also, beam restriction will keep the total amount of tissue irradiated to a

minimum so fewer scattered photons are created consequently the image quality will be

improved. It is important to control scatter since it has no useful diagnostic effect.

Another principle factor in reducing scatter is kilovoltage or the penetrability of the

beam. As kVp is increased, fewer atoms interact with the tissue, and more pass through

to end up on the image receptor. In radiography, kilovoltage is selected based

predominantly on the size of the part examined. Whenever kilovoltage is increased

more scatter will result unless it is accompanied by a reduction in mAs thereby reducing

scatter and the dose to the patient. Thus beam restriction along with technical factors

are very important aspects of radiation protection by reducing the patient dose and

improving the image quality

(Carlton & Adler, 2006). Aperture diaphragms are the simplest type of beam-

restricting device. It is a flat piece of lead containing a hole in the center that attaches to

the x-ray tube port. The opening can be made in any size or shape, but rectangular is

the most common. The main advantages of aperture diaphragms are there simple

design, low cost, and ease of use. The main disadvantage is the increase in the

unsharpness around the periphery of the image known as penumbra. Other

disadvantages include off-focus radiation and no light field for use in positioning.

Aperture diaphragms are used in special procedure angiography studies

Cones or cylinders are essentially aperture diaphragms with metal extensions

that can be either straight or flared and attach to the x-ray tube housing. Cones are

extensions that flare and cylinders are straight but both are routinely called cones. The

longest cone with the smallest diameter will provide the greatest beam restriction. The

advantage of cones is there low cost and ease of use. One difficulty with using cones is

alignment. The physical weight of the cones can sometimes cause the tube to angle

slightly when used with a horizontal beam causing cone cutting if the central ray is not

checked carefully. Today, cones are reserved for select areas of radiology such as

sinuses, L5/S-1 spine, and dental radiographs.

(Forshier, 2009) Collimators are the most widely used beam restricting

device because they contain a light source to help the radiographer center the x-ray

beam. They are composed of a lamp, mirror, and a pair of upper and lower lead

shutters that are at right angles to each other and move independently. Upper shutters

absorb the off focus radiation before it leaves the tube and the lower shutters further

restrict the beam to the area of interest. Collimators permit an infinite number of field

sizes using only one device and hence reduce the light field to only the area of interest

resulting in reduced patient exposure. Some equipment is supplied with automatic

collimators that are electronically interlocked with the Bucky tray so the x-ray beam is

automatically restricted to the size of the cassette. These devices are known as positive

beam limitation (PBL) devices. Accuracy within 2% of the SID is required with all PBL

devices

Ultimately, it is the responsibility of the radiographer to use proper collimation

and under no circumstances should the exposure field exceed the size of the image

receptor. The radiographer should always limit the field to the part being examined

thereby improving the image quality and minimizing the patient dose.

C. Synthesis

The review of related literature gave richer concepts on Quality

Control of Scattered Radiation .Radiographer must conscientiously avoid unnecessary

radiation exposure as well as strive to keep patient dose to an absolute minimum.

Radiographer must follow the ALARA Principle (As low as reasonably achievable) as

they carry out their tasks.

The work of the authors were focused on broad and informational

function books. This present study is all about using beam restricting device , or

limitation of field size, and probably the single most important factor in keeping

patient dose to a minimum.

Three basic type of Beam Restrictor , Aperture Diaphragm , Cone and Cylinder

and Collimation.

Aperture diaphragms are the simplest type of beam-restricting device. It is a flat

piece of lead containing a hole in the center that attaches to the x-ray tube port.

Cones or cylinders are essentially aperture diaphragms with metal extensions

that can be either straight or flared and attach to the x-ray tube housing.

Collimators are the most widely used beam restricting device because they

contain a light source to help the radiographer center the x-ray beam.

Scatter Radiation Control

The radiographer must strive to minimize the quantity of

scatter that reaches the IR

Restrict the x-ray beam size to the size of the anatomical

structures required to demonstrate in the image

No reason to leave collimators open to extend beyond

the IR size

Objective is to decrease patient radiation dose, and

achieve optimum contrast.

However, the present study is quite similar to the studies mentioned in the sense

that all deal with professional job related tasks of the researchers.

Chapter 3

Research Methodology

This Chapter represents a description of the method of research used,

respondent of the study, instrumentation, and analysis of data.

In the event of this study the researchers will use a descriptive method.

Employing the substantial procedures and activities performed will help validate

the findings of this present study.

Research Design

In conducting the study, the researcher will use a descriptive method, which is

considered the objective of the study of the study. This involves collecting

numerical data to test hypotheses or answer question concerning validated were

the primary source of data which were utilized in this study. Data that were

gathered were tabulated, statistically analyze and interpreted.

Research Participants

The researchers will be using purposing sampling, due to special

characteristics that the research participants possess. The individual that are

selected are those who have the expertise or experience related to the purpose

of the study.

Research Instrument

Questionnaire was used as a research instrument. It is used to

gather data on the profile of the respondents in terms of age, gender, specialty

and imaging technique performed by the technologist and the competency and

their skill in diagnostic radiography.

The instrumentation used in the collection of data was twenty (20)

questionnaires.

Different schools were consulted as to the authenticity of every area; the

respondents became local pint who answered the questionnaires.

In the questionnaire, each respondent was asked to answer the questionnaire

that contains question related to hypothesis which include the Quality Control of

Scattered Radiation. The respondent were asked topic related on how to restrict

and reduce the production of scattered radiation as well as to strive to keep

patient dose to an absolute minimum and criticize according to the level of choice

by A. - YES, B. – NO, C. – MAYBE, D. – SOMETIMES, E. – NONE AT ALL.

Finally, they were asked how, according to there expertise.

Data gathering procedure

The survey was conducted at M.V Santiago Medical Center.

Questionnaires were distributed to the respondents and collected after one week.

The data collected, tabulated, analyzed, and interpreted by using statistical

formulas.

Statistical Treatment

the researcher were able to interpret the data gathered using the

statistical formula. Data respondents, profile and the Quality Control of Scattered

Radiation were quantified using percentage.

PERCENTAGE. This test is used in order to describe the profile of the

respondents:

The Following:

F P = Percentage

P = _____________ x100 F = Frequency

N

N = No. Of

Respondents (population)