IMAGING ARTIFACTS X- Ray Ct & Medical Ultrasound

112 Pages·2004·3.4 MB·English

Sudan University of Science & Technology
College of Medical Radiological Science
Department of Radiological Technology
SD0000012
IMAGING ARTIFACTS
Comparative Sludy in
X- Ray Ct & Medical Ultrasound
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2. CONTENTS.
1.1 RESEARCH PROPOSAL.
1.2 INTRODUCTION.
Contents
Part one (1)
Section one [1]
1. Acknowledgement.
2. Contents.
1.1 Research Proposal.
1.2Introduction.
Part two (2)
2.1 Artifacts in X-RayCT.
2.1.1 Equipment
2.1.2 .Technique
2.1.3 Patient
2.2 Reducing of Artifacts in CT.
2.2.1 Equipment
2.2.2 Technique
2.2.3 Patient
Part three (3)
3.1 Artifact in Medical Ultrasound.
3.1.1 Equipment
3.1.2 Technique
3.1.3 Patient
3.2 Reduction of Artifacts in Ultrasound
3.2.1 Equipment
3.2.2 Technique
3.2.3 Patient
Part Four (4)
4.1 Comparative Studies Tables.
4.2 Data Collection.
4.3 Discussion of Results.
Part Five (5)
5.1 Q.C
5.2 Conclusion & Recommendation
Reference
Appendix
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Chapter One
Research Proposal:
Imaging Artifacts: A Comparative Study
In X-Ray CT & Medical Ultrasound
Introduction:
This study draws attention forwards the quality of imaging process.
Concerning the factors that may observe the diagnosis out come which
represents the aim of the whole process of imaging technology. Imaging
artifacts is one of the major limitation factor that after and decrease the
value of diagnosis and out come in conventional radiography we can
estimate the factors that cause artifacts which could be easily evaluated
because most of the parameters in imaging process are fixed to some
extend and the accessing of the imaging approximately in direct mode.
But the errors which leads to artifacts skill arise in digital imaging
"Concerning CTV U/S", the accessing process taken over several steps
involve conversion from analogue format to digital and vice versa; and
application of computer technology program needs careful awareness.
Tiny errors many arise artifact, issue, errors leads to artifact, on digital
imaging can't predicted unless listed and discussed on a cord of practices
according to the operational protocol.
Statement of problem:
The digital imaging nowadays cover most of investigations done in
radiography department ever the conventional process started earlier and
cover along of time and the technologist gain experience skill errors lead
to artifacts seem to be more while digital imaging replace the conventional
imaging in a fast steps it carry also the same errors with the new errors,
that may warser the new practice as a whole.
Reasons for Choice This Project:
There were a lot of errors in different department that deals with
digital imaging can be observed by any general observer this issue
reflected on the fetal report at the level of diagnosis and this will affect the
quality of patient cane and may be the morbidity rate as well as mortality
rate.
Objectives of the Project:
The main objective of this study is to high light the artifacts and the
source of errors that lead to artifact formation and we can summarize the
main objectives on the following points:
(1) Consider and identify the artifacts on each modality.
(2) Show the cause of artifact.
(3) Resolve and eliminate the reasons that lead to artifacts
formation in imaging.
(4) Establish proper quality control techniques issue set tha base
line limits of artifact causation.
Hypothesis:
1- The presence of artifact creates problems in diagnosis.
2-The cause errors leading to imaging artifact that affect the
diagnosis more in digital U/S than CT.
3- Lack of quality assurance programs maximizes the presence of
faults leading to imaging artifact.
4- Imaging artifacts affects the quality of patient care and delay
medical diagnosis and treatment, and hence increase patient
waiting time.
Previous Studies:
From what we read in the previous research studies (1,2,3) we did
notice that there was just listing of faults without indicating any reason (s)
or causes except in medical ultrasound. However, we planned to research
it from our locate experts in CT and medical ultrasound in the teaching
hospitals and medical centres according to the values of the code of
practice.
Research Methodology:
In this study of have taken the scientific method in the field of X-ray
CT and medical ultrasound imaging.
Data Collection:
1-Questionnaire.
2- Interviews.
Using both in the following variable:
a. Equipment factors.
b. Patient factors.
c. Technique.
Place & Period of Study:
Sudan- Khartoum March/July 1998 (Teaching Hospitals and Medical
Imaging Centers).
Introduction
Diagnostic imaging is an important element in the practice of the
modern medicine without it medical treatment would have been
impossible. Radiation medicine had seen many changes since 1895, where
only early tuals. A radiation therapy and radoidiagnosis. Today imaging
has many source of electromagnetic radiation "EMRs" and each source
has its advantages over the other. However, medical radiation education
had also seen more advances in the medical sciences and medical
education, which lead to the discoveries of new methods, and techniques
in these fields.
There were also new approaches to refine and perfect the practice of
radiologic techniques and to reduce radiation exposure, patient waiting
time and cost. We have seen lots of new imaging modalities, quality
assurance and quantity control procedures in all modalities to produce
images of high quality and more diagnostic information.
Here, we have taken the lead to research and study carefully how we
could participate in the area of reducing image retakes and study the
reasons of image artifacts in diagnostic imaging.
In this regaid we are researching on artifacts in X-ray computed
tomography and medical ultrasound and considering how these artifacts
may be eliminated.
PART 10W
ARTIFACTS IN X-RAY CT.
2.1.1 TECHNIQUE
2.1.2 EQUIPMENT
2.1.3 PATIENT
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8
Artifacts
This section deals with experience gained with the original model
EMI 160 xl60 matrix scanner. Modification, because of the experience
with EMI CT 1010 scanner and other scanning systems, is expected. This
section should be of considerable value in the understanding of the basic
causes of artifact production and sources of error despite such
modifications.
Artifacts:
Motion and high-differential attenuation value of adjacent tissues are
principal cause of artifacts. Technical errors are also responsible.
Motion Artifacts:
Motion of a point places that point different computed positions
during the scanning cycle. This false representation usually produces a
linear artifact called a "streak". Point A scanned at 0 degree is again
scanned at 180 degrees with an interval time delay. A change in point A
position will produce computer error in the form of a streak. Computer
error due to movement will, therefore, be more marked along the vertical
(Odegree/180degrees) line, because of motion during the time that elapses
between the two readings. The head can rotate in all directions, producing
a variety of streaking outside or inside the skull vault. Assuming that the
scanning time is constant, head support, patient cooperation and sedation
are factors to consider in order to diminish motion artifact. The faster