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Chapter 2COMPARISON OF MAMMOGRAPHYRADIATION DOSE VALUES OBTAINED FROMDIRECT INCIDENT AIR KERMAMEASUREMENTS WITH VALUES FROMMEASURED X-RAY SPECTRAL DATAAccepted for publication in Applied Radiation and Isotopes28
AbstractThe application of X-rays and ionising radiations for diagnostic radiology requires that theprocedure is justified and optimised and that the exposure to the patient is kept as low aspossible, without compromising image information. X-ray mammography is considered to bethe most sensitive technique currently available for early detection of breast cancer. Themagnitude of the absorbed radiation dose to the breast from mammography X-ray beamsforms an important part ofthe quality control ofthe mammographic examination since it givesan indication of the performance of the mammographic imaging system as well as anestimated risk to the patient. In this work mean glandular dose (MGD) values were obtained atvarious tube potentials and tube loadings (TL) using direct measurements of the incident airkerma (ESAK) at the surface of a standard breast phantom and also from spectralmeasurements acquired with a solid-state detector. Comparisons of the MGD values thusderived are presented and the relationship between MGD, phantom thickness, image qualityand tube operating parameters is discussed.2.1. IntroductionBreast cancer is reported to be the second highest cause of cancer deaths in women today(after lung cancer), with an estimation of 400,600 deaths from breast cancer for 2001(GLOBOCAN, 2000). Breast cancer is also the most common cancer among women,excluding nonmelanoma skin cancers. In 2001, World Health Organization (WHO) predictedmore than 1.2 million new breast cancer cases (globally) while in United States, both theAmerican Cancer Society and the National Cancer Institute estimated approximately 192,200new cases ofinvasive breast cancer cases for 2001. Male breast cancer has also been reported29
Page 2 and 3: Prof. L MakhubuPresidentTWOWSTriest
Page 4 and 5: DOSIMETRIC TECHNIQUES FOR MAMMOGRAP
Page 6 and 7: ABSTRACTScreening of asymptomatic w
Page 8 and 9: materials. In current practice diam
Page 10 and 11: ACKNOWLEDGEMENTSI would like to ren
Page 12 and 13: CONTENTTitle page .Declaration.....
Page 14 and 15: Chapter 1GENERAL INTRODUCTION
Page 16 and 17: (Siemens, 2004). In the screening p
Page 18 and 19: Xeromammography and screen-film mam
Page 20 and 21: target produces characteristic X-ra
Page 22 and 23: while maximizing the focal spot-to-
Page 24 and 25: et al. (1996) concluded that for al
Page 26 and 27: An accurate knowledge of the output
Page 28 and 29: determine the dose (K,) to the entr
Page 30 and 31: equation (Tucker et aI., 1991) in o
Page 32 and 33: simulates the experimental setup an
Page 34: REFERENCESAdam W. et al. (RD42 Coll
Page 37 and 38: GLOBOCAN (2000). Cancer incidence,
Page 39 and 40: Plankskoy B. (1980). Evaluation ofd
Page 44 and 45: ut this accounts for less than 1% o
Page 46 and 47: calculated (Calicchia et al., 1996)
Page 48 and 49: current-exposure time product (tube
Page 50 and 51: 2.2.6. Contrast measurementsFilm co
Page 52 and 53: values using a factor 0.873 (Wolbar
Page 54 and 55: Table 2.1: The HVL values of the ma
Page 56 and 57: Table 2.2: Comparison of ESAK and M
Page 58 and 59: without collimation (Figures 2.4 an
Page 60 and 61: 100 r"--------------;:====:=:;__,I:
Page 62 and 63: 0.45[_20rnnPMMA--G-30mnPMMAO'i _40r
Page 64 and 65: 2.5. CONCLUSIONThe study has shown
Page 66 and 67: Dance D. R., Skinner C. L., and Car
Page 68 and 69: Wu X., Barnes G.T., and Tucker D.M.
Page 70 and 71: ELSEVIERAvailable online at www.sci
Page 72 and 73: Chapter 3SEGMENTED MULTIFIT OF POLY
Page 74 and 75: 2 M Assiamah et al. I Radiation Phy
Page 76 and 77: 4.,.,M. Assiamah et af. I Radiation
Page 78 and 79: 6 M Assiamah et al. I Radiation Phy
Page 80 and 81: PERGAMONAvailable online at www.sci
Page 82 and 83: M Assiamah et al: I Radiation Physi
Page 84 and 85: M. Assiamah e! aJ. J Radiation Phys
Page 86 and 87: aorEi!lM. Assiamah et al. I Radiati
Page 88 and 89: M Assiamah et a/. I Radiation Physi
Page 90 and 91: At. Assiamah et al. I Radiation Phy
Page 92 and 93:
At. Assiamah et al. I Radiation Phy
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Chapter 5SYNTHETIC DIAMOND AS A RAD
Page 96 and 97:
The mass density ofdiamond is 3.515
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5.2. Selection ofexposnre geometry
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absorption levels of both exposure
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evolutions per minute. The polished
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just over 1 micron. In the measurem
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characterized by the quantum number
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(200 A)/gold (2000 A), in an ultra
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5.7.1. Selection of polarizing volt
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~:j12010080/~"~s 60"-0~: "402040 80
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6055•"~-e,5045&40~0iFc 35'"3025
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180160140120F:j 100F40200 0 30~00 "
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180160140120~~100~~~c 80a 0.Beforea
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22020000180 0 00160oi~ 140"~~ 120~"
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No. Descrintion Material No. Descri
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Figure 5.21 : Photograph of Mark UA
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examination reduces radiation dose
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Lightowlers E.C. and Dean P.J. (196
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Chapter 6COMPARATIVE STUDIES OF MEA
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(Briesmeister, 1993) and PENELOPE (
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density functions and thus on the c
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6.4.1 Geometry definition fileSimul
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construction of the probe was suppl
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The parameters Nabs, Na and N] are
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Table 6.1: Comparison oftotal depos
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6.5.1.3. Edge-on geometry versus fl
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Table 6.4: Comparison oftotal depos
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The results ofthe calculations have
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shows a 2D display of the geometry
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occurred, resulting in reduced numb
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Table 6.8: Calculated deposited ene
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Table 6.10: Calculated deposited en
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Table 6.12: Calculated deposited en
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Suggested furthermore is a method w
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~ "" 0 0-~"~" ;>.~1.2• Measured1.
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Briesmeister J.F. (1993). MNCP- A g
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Sempau J., Acosta E., Baro 1., Fema
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Radiation doses from mammography X-
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Radiation dose from mammography X-r
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their influences. An alternative me
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Appendix 1APPLIED UNCERTAINTIES IN
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ii) Tube loading (mAs) meter accura
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Name:Type:Dimension:Mass:Thickness:
Page 180:
42"" Congress and Winter School oft
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