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Published byNicholas Wilkinson Modified over 9 years ago
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Hadi Tadayyon June 11, 2012
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Clinical challenge ◦ High risk for metastasis Characterized as: ◦ > 5 cm long axis ◦ Skin/chest wall involvement ◦ Lymph node involvement Tumour grade – a histological feature that is a prognostic indicator and is important for treatment design ◦ Determined from pathological examination of biopsy sample ◦ Higher grade higher degree of malignancy / poorer prognosis Our goal: ultrasonically detect variation in tumour grades
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Midband fit, slope, and intercept used to differentiate: ◦ Prostate cancer from benign tumours 1 ◦ Metastic from non-metastatic lymph nodes 2 Acoustic scatterer spacing used to characterize breast lesions as benign or malignant 3 1.Feleppa et al., 2004 IEEE Trans UFFC, 43(4), 609-619, (1996) 2.Mamou et al., Ultrasound in Med. & Biol., 37(3), 345–357, (2011) 3.Y. Bige et al., Ultrasonics 44, 211–215, (2006)
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Can LABC tumours be characterized in terms of grade using quantitative ultrasound? Given: ◦ Retrospective in-vivo clinical breast data (N=43) ◦ A diagnostic ultrasound machine
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Tumour ROI 1 cm Normal breast ROI QUS Midband fit (MBF) Slope (SS) Intercept (SI) Scatterer spacing (SAS) GI (N=3) GII (N = 22) GIII (N = 18) 10 MHz fc linear array transducer (Ultrasonix, Canada) 4-7 cm depth 5 MHz 50% bandwidth Normal tissue ROI
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Depth-dependent spectral normalization (reference phantom) Variable bandwidth linear regression Discrete depth spectral normalization (reference reflector) Auto-regressive (AR) spectral estimation and autocorrelation- derived scatterer spacing
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Mann-Whitney test: p = 0.032
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GI GII GIII NT 0 0.5 SAS (mm) 10 um 1 cm
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Mean spacing between glandular islands = 200 um 100 um
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A potential method to non-invasively characterize tumour grade was proposed Scatterer spacing statistically different among tumour grades (ANOVA test & Mann-Whitney test) Scatterer spacing is linked to spacing between glandular islands Small sample size for GI ◦ In large population study – 362/1409 = 25% ◦ In our study, 3/43 = 7% Cannot evaluate classification due to insufficient parameters Future directions: investigate other QUS parameters
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Czarnota Lab, University of Toronto Dr. Czarnota Dr. Omar Falou Mike Papanicolau Sara Iradji Ervis Sofroni Ryerson University Dr. Lauren Wirtzfeld University of Illinois Dr. Michael Oelze CGSD
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Increasing risk of metastasis Grade IGrade IIGrade III Total score 3-5 6-78-9
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