Causal factors and potential clinical implications of variation in mammographic density assessment
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USyd Access
Type
ThesisThesis type
Doctor of PhilosophyAuthor/s
Damases, ChristineAbstract
The thesis explores various measures of MBD assessment in digital mammography (DM) and assesses inter-‐reader variability using BI-‐RADS® and RANZCR scales based on four studies. Methods: In studies 1 and 2, 40 images from 20 US women—acquired one year apart—were processed using ...
See moreThe thesis explores various measures of MBD assessment in digital mammography (DM) and assesses inter-‐reader variability using BI-‐RADS® and RANZCR scales based on four studies. Methods: In studies 1 and 2, 40 images from 20 US women—acquired one year apart—were processed using Volpara®densityTM software. Observers (20 experts) assessed the images using BI-‐RADS®. Study 1 used spearman’s correlation (ρ) to examine relationships between the systems for BI-‐RADS®, VDG, and AvBD%. Study 2 examined inter-‐observer agreement using BI-‐RADS® 4-‐point and binary scales. In study 3, 26 Australian radiologists assessed 40 images using RANZCR synoptic scales. Agreement on RANZCR scales between radiologists was expressed as Cohen’s Kappa (κ). Study 4 used a weighted Kappa (κw) statistic to test for agreement between MBD assessment schemes and pairs of observers based on BI-‐RADS® scores from 20 ABR examiners, 24 UK practitioners, and RANZCR radiologists. Results: In study 1, both BI-‐RADS® (ρ=0.904; p<0.001) and Volpara (ρ=0.978; p<0.001) showed positive correlations between the systems. Study 2 reported BI-‐RADS® inter-‐reader agreement of 0.565 [95% CI=0.519–0.610] on the 4-‐point scale and 0.855 [95% CI=0.824–0.866] on the binary scale. Study 3 reported RANZCR inter-‐ reader agreement of 0.360 [95% CI=0.308–0.412] on the 4-‐point scale and 0.726 (95% CI=0.675–0.777) on the 2-‐point scale. Study 4 reported agreement (κw) of 0.10 [95% CI=-‐ 1.13–0.43] between ABR and RANZCR radiologists, 0.25[95% CI=-‐0.42–0.61] between ABR and UK practitioners, and 0.95 [95% CI=0.91–0.97] between RANZCR radiologists and UK practitioners. Conclusion: Results show lesser variation on binary scale than on 4-‐point scale for both BI-‐RADS® and RANZCR. Volpara®densityTM MBD measurement shows better agreement between the imaging systems than BI-‐RADS®. This work provides insight into potential implications of inconsistency in MBD assessment on breast cancer risk stratification.
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See moreThe thesis explores various measures of MBD assessment in digital mammography (DM) and assesses inter-‐reader variability using BI-‐RADS® and RANZCR scales based on four studies. Methods: In studies 1 and 2, 40 images from 20 US women—acquired one year apart—were processed using Volpara®densityTM software. Observers (20 experts) assessed the images using BI-‐RADS®. Study 1 used spearman’s correlation (ρ) to examine relationships between the systems for BI-‐RADS®, VDG, and AvBD%. Study 2 examined inter-‐observer agreement using BI-‐RADS® 4-‐point and binary scales. In study 3, 26 Australian radiologists assessed 40 images using RANZCR synoptic scales. Agreement on RANZCR scales between radiologists was expressed as Cohen’s Kappa (κ). Study 4 used a weighted Kappa (κw) statistic to test for agreement between MBD assessment schemes and pairs of observers based on BI-‐RADS® scores from 20 ABR examiners, 24 UK practitioners, and RANZCR radiologists. Results: In study 1, both BI-‐RADS® (ρ=0.904; p<0.001) and Volpara (ρ=0.978; p<0.001) showed positive correlations between the systems. Study 2 reported BI-‐RADS® inter-‐reader agreement of 0.565 [95% CI=0.519–0.610] on the 4-‐point scale and 0.855 [95% CI=0.824–0.866] on the binary scale. Study 3 reported RANZCR inter-‐ reader agreement of 0.360 [95% CI=0.308–0.412] on the 4-‐point scale and 0.726 (95% CI=0.675–0.777) on the 2-‐point scale. Study 4 reported agreement (κw) of 0.10 [95% CI=-‐ 1.13–0.43] between ABR and RANZCR radiologists, 0.25[95% CI=-‐0.42–0.61] between ABR and UK practitioners, and 0.95 [95% CI=0.91–0.97] between RANZCR radiologists and UK practitioners. Conclusion: Results show lesser variation on binary scale than on 4-‐point scale for both BI-‐RADS® and RANZCR. Volpara®densityTM MBD measurement shows better agreement between the imaging systems than BI-‐RADS®. This work provides insight into potential implications of inconsistency in MBD assessment on breast cancer risk stratification.
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Date
2016-06-30Licence
The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission.Faculty/School
Faculty of Health SciencesDepartment, Discipline or Centre
Discipline of Medical Radiation SciencesAwarding institution
The University of SydneyShare