Figure 4.2 comparison between CTDIvol and DLP for abdomen

56 Pages·2016·2.23 MB·English

Sudan Academy of Sciences
Atomic Energy Council
• "sr a ^ ** ir? i.rjCT:
Assessment o f Radiation Doses to Adult Patients in Computed
Tomography Procedures
K abashi H om m ed a Y o sif K abashi
A T h esis subm itted for Partial F ulfillm ent for requirement o f M .sc D egree in
Medical Physics
Supervisor:
D r.M o h a m ed M o h a m ed O m er. M. Y o u sif
Associate Professor
October 2015
S u d a n A c a d e m y o f S c ie n c e s ( S A S )
Atomic Energy C
1
c
A s s e s s m e n t o f R a d ia tio n D oses to A d u lt P a tie n ts in
C o m p u te d T o m o g r a p h y P r o c e d u r e s
Bv:
Kabashi Hommeda Yosif Kabashi
Examination committee
Title
Name Signature
|
P
i
S u p e r v i s o r
P r o f . . M o h a m e d M o h a m e d O m c r
f 1 *1 1 ■ ™ * 1
Prof. Farous Habbani
E x t e r n a l e x a m i n e r
i
______ _^_. _^__i
■
Decem ber 2015
m
*
*
Dedication
My friends
ff
Acknowledgements
My g re a t thanks to my supervisor Dr.
Mohammad Om ar Yousif for his
supervision, inexhaustible patience and
unlimited help.
My thanks extend to my colleagues
who helped me to collect the data and
to complete this study.
fit
Abstract
The purpose of this study was to assess radiation dose ana estimate
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dose m three different detectors of CT scanners li
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for routine CT investigation . A total of GO patients were examined m this s u e ; .
20 patients for dual slice (10 patient for chest and 10 for abdomen. _0 pahen;
sixteen slices (10 for chest and 10 for abdomen) and 20 ; \
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for chest and 10 for abdomen). The mean dose values foi i I t’Os1
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slices were DLP 1 5 2 .4 -5 6 u 6 mGv.cm, CTPIvoI
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2.1 3±0.974mSv, for dual slice the mean values were h i ’
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16/±55.31mGv.cm,CTDIvol ?.02±1.41mGv HP 2.3-0.
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dose values for sixtv-four slice were PLF ( G . - l . P . f n i G m i m T P . .
15.08±0.252 ED 7.9±0.61mSv and for CT abdomen the meai
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sixteen slices were PEP 306.6=43.63mGv.cm, CTPIvoI O. tbeO 3 llllUV
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4.39±1.83mSv, while for dual slice the mean dose values were PIT _oo
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/8.46mGy.cm, CTDIvol 27±1.46mGy ED 3.12±1.18mSv, while for sixty-tout
IV
mean dose values were DLP
slic e s t h e
CTDIvol2 1 .5 6±0 .2 5 0 mGy ED 1 0.4 2 ±0 .4 3 mSv Dual she
radiation dose while 16 and 64 slice scanners delivered
dose. CT dose optimization protocol is not implemented in
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2.1.1 Parts and components o f the CT scan machine
2.1.2 CT g a n tr y .........................................................
2.1.3 X-ray tube, collimation &
filtration......................................................................
2.1.4 D etecto rs...........................................................
2.1.5 Data acq u isitio n ................................................
2.1.6 CT patient table or c o u c h .................................
2.2 Radiographic tequnique......................................
2.2.1 Patient preparation............................................
2.3 Radiation dose from CT s c a n .............................
2.3.1 Quantitative m e a su re s......................................
2.3.2 Cancer riscks associated with CT s c a n s .........
2.4 Radiation dose.......................................................
2.4.1 Absorbed d o s e ...................................................
2.4.2 Equivalent d o s e ................................................
2.4.3 Effective dose....................................................
2.5CT p ara m e te rs.......................................................
2.5.1 Tube potential ( k V p ) .........................................
2.5.2 Tube current -tim e product (m A s )...................
2.5.3 P itc h ...................................................................
2.6 Methods o f measurement in C T ..........................
2.6.1 Computed tomography dose index (C T D I).....
2.7 Radiation units and m easurem ent........................
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