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Effects of Slice Thickness Filter in Breast Tomosynthesis
Filtered Back Projection Reconstruction
Linlin Cong 1, Weihua Zhou 2, *Ying Chen 1,2
1Biomedical Engineering Graduate Program
2Department of Electrical and Computer Engineering, Southern Illinois University, Carbondale, IL 62901
(* Corresponding Author)
IEEE GENSIPS 2011
Medical Imaging Laboratory
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OUTLINE
Introductions
Breast Tomosynthesis Imaging
System
Tomosynthesis Image
Reconstruction and Simulation
Results
Conclusions
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Introduction
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Breast Cancer Breast Cancer:
• Most common cancer among women worldwide;
• Second leading cause of cancer related death among women.
Symptoms:• No symptom in the early stage, regular
breast exams are important;• Breast lump or lump in the armpit,
change in the size, shape, fluid from the nipple.
• Once the patient is diagnosed with breast cancer, next step is staging (Grade: 0, I, II, III, IV). Higher the grade is, poorer the outcome of the treatment will be.
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Mammography
Traditional mammography:• Currently, a standard and important clinical
screening and diagnosis for early detection of breast cancer;
• Cheap, low radiation dosage. Limitations of traditional mammography:
• 20% false negative rate, many call backs from screening;
• low positive predictive value, about 30% of breast cancers are still missed in mammography;
• 2D imaging system, difficult to distinguish a cancer from overlapped breast tissues.
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Breast Tomosynthesis
3D slice images provide depth information
Improve conspicuity of structure by removing the visual clutter associated with overlying anatomy
Promising to reduce recall rates, and to increase cancer detection accuracy.
Low dosage; relatively cheap Extensive attentions from academic
communities and industrial vendors have been paid to this promising field.
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Breast Tomosynthesis Imaging System
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Siemens Mammomat Inspiration
GEIMS GIOTTO Hologic Selenia Dimensions
Examples of current commercial breast tomosynthesis prototype systems :
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Most of these systems re-utilize the traditional partial isocentric mammography design.
X-ray tube moves in an arc across the breast
Series of low dosage images are acquired at different angles
Limitation is X-ray tube’s movement may introduce motion blur and cause patients’ discomfort.
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A Novel Nanotechnology Enabled Digital Breast Tomosynthesis
Prototype System Invented by our collaborators at the
University of North Carolina Chapel Hill Built up with fixed multi-beam field-
emission X-ray sources, no movement of X-ray tubes;
Total scanning time: about 11.2 seconds for typical 25 projection views
Advantages:• No motion blur• Less scanning time, so decreasing the
waiting time
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A novel multi-beam x-ray source developed by Zhou Lu et al.
• Fixed multi-beam field-emission x-ray (MBFEX) sources based on unique properties of carbon nanotube electron emitters.
• The total scan time for a typical 25 views is about 11.2 seconds.
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Tomosynthesis Image Reconstruction and
Simulation
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BREAST TOMOSYNTHESIS IMAGING SYSTEM SIMULATION
The image acquisition system we used to get the projection images was simulated based on the parallel imaging system.
• 25 X-ray sources.
• The path of tubes is parallel to the plane of detector.
• Two sets of data were simulated to investigate the filter effects:
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The image acquisition system:
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IMAGING SYSTEM: Data 1 One Sphere:
• placed at 30mm above the detector • radius = 5mm.
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IMAGING SYSTEM: Data 2 Two overlapping spheres were simulated.