Dr. S. Cheenu Kappadath Profile

Dr. S. Cheenu Kappadath

Assistant Professor

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Author

Publications (10)

Proceedings Article | 2 March 2006 Paper

Comparison of two detector systems for cone beam CT small animal imaging: a preliminary study

Yang Meng, Chris Shaw, Xinming Liu, Mustafa Altunbas, Tianpeng Wang, Lingyun Chen, Shu-Ju Tu, S. Cheeenu Kappadath, Chao-Jen Lai

Proceedings Volume 6142, 614245 (2006) https://doi.org/10.1117/12.656690

KEYWORDS: Imaging systems, Charge-coupled devices, X-ray computed tomography, Sensors, X-rays, X-ray detectors, Preclinical imaging, CCD image sensors, CCD cameras, X-ray imaging

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Proceedings Article | 2 March 2006 Paper

An accurate scatter measurement and correction technique for cone beam breast CT imaging using scanning sampled measurement (SSM)technique

Xinming Liu, Chris Shaw, Tianpeng Wang, Lingyun Chen, Mustafa Altunbas, S. Cheenu Kappadath

Proceedings Volume 6142, 614234 (2006) https://doi.org/10.1117/12.656655

KEYWORDS: X-ray computed tomography, Lead, Breast, Scatter measurement, Sensors, Mammography, X-rays, Statistical analysis, Radiation effects, Image acquisition

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Proceedings Article | 20 April 2005 Paper

Dual-energy digital mammography for calcification imaging: improvement by post-image processing

S. Kappadath, Chris Shaw, Chao-Jen Lai, Xinming Liu, Gary Whitman, Wei Yang

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.596903

KEYWORDS: Image processing, Tissues, X-rays, Sensors, Digital mammography, Breast, Image filtering, X-ray imaging, Signal processing, Imaging systems

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Proceedings Article | 20 April 2005 Paper

Cone-beam CT breast imaging with a flat panel detector: a simulation study

Lingyun Chen, Chris Shaw, Shu-Ju Tu, Mustafa Altunbas, Tianpeng Wang, Chao-Jen Lai, Xinming Liu, S. Kappadath

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.597065

KEYWORDS: Breast, Sensors, Tissues, X-ray computed tomography, X-ray detectors, X-rays, Breast imaging, Imaging systems, Image filtering, X-ray imaging

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This paper investigates the feasibility of using a flat panel based cone-beam computer tomography (CT) system for 3-D breast imaging with computer simulation and imaging experiments. In our simulation study, 3-D phantoms were analytically modeled to simulate a breast loosely compressed into cylindrical shape with embedded soft tissue masses and calcifications. Attenuation coefficients were estimated to represent various types of breast tissue, soft tissue masses and calcifications to generate realistic image signal and contrast. Projection images were computed to incorporate x-ray attenuation, geometric magnification, x-ray detection, detector blurring, image pixelization and digitization. Based on the two-views mammography comparable dose level on the central axis of the phantom (also the rotation axis), x-ray kVp/filtration, transmittance through the phantom, detected quantum efficiency (DQE), exposure level, and imaging geometry, the photon fluence was estimated and used to estimate the phantom noise level on a pixel-by-pixel basis. This estimated noise level was then used with the random number generator to produce and add a fluctuation component to the noiseless transmitted image signal. The noise carrying projection images were then convolved with a Gaussian-like kernel, computed from measured 1-D line spread function (LSF) to simulated detector blurring. Additional 2-D Gaussian-like kernel is designed to suppress the noise fluctuation that inherently originates from projection images so that the reconstructed image detectability of low contrast masses phantom can be improved. Image reconstruction was performed using the Feldkamp algorithm. All simulations were performed on a 24 PC (2.4 GHz Dual-Xeon CPU) cluster with MPI parallel programming. With 600 mrads mean glandular dose (MGD) at the phantom center, soft tissue masses as small as 1 mm in diameter can be detected in a 10 cm diameter 50% glandular 50% adipose or fatter breast tissue, and 2 mm or larger masses are visible in a 100% glandular 0% adipose breast tissue. We also found that the 0.15 mm calcification can be detected for 100μm detector while only 0.2 μm or above are visible for 200 μm detector. Our simulation study has shown that the cone-beam CT breast imaging can provide reasonable good quality and detectability at a dose level similar to that of two views\mammography. For imaging experiments, a stationary x-ray source and detector, a step motor driven rotating phantom system was constructed to demonstrate cone beam breast CT image. A breast specimen from mastectomy and animal tissue embedded with calcifications were imaged. The resulting images show that 355-425 μm calcifications were visible in images obtained at 77 kVp with a voxel size of 316 μm and a center dose of 600 mrads. 300-315 μm calcifications were visible in images obtained at 60 kVp with a voxel size of 158 μm and a center dose of 3.6 rads.

Proceedings Article | 6 May 2004 Paper

Slot scanning versus antiscatter grid in digital mammography: comparison of low-contrast performance using contrast-detail measurement

Chao-Jen Lai, Chris Shaw, William Geiser, Srinivas Kappadath, Xinming Liu, TianPeng Wang, Shu-Ju Tu, Mustafa Altunbas

Proceedings Volume 5368, (2004) https://doi.org/10.1117/12.535986

KEYWORDS: Digital mammography, Imaging systems, X-rays, Image quality, Sensors, Mammography, Image processing, Charge-coupled devices, X-ray imaging, Manufacturing

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Proceedings Article | 6 May 2004 Paper

Dual-energy digital mammography for calcification imaging: theory and implementation

Srinivas Kappadath, Chris Shaw, Chao-Jen Lai, Xinming Liu, Gary Whitman

Proceedings Volume 5368, (2004) https://doi.org/10.1117/12.534115

KEYWORDS: Tissues, Aluminum, Signal to noise ratio, X-rays, Breast, Sensors, Calibration, Mammography, Visualization, Signal attenuation

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Proceedings Article | 5 June 2003 Paper

Contrast-to-noise and exposure measurements of an aSi:H/Csl(Tl) flat-panel based digital radiography system using a QC chest phantom

Xinming Liu, Chris Shaw, Peter Balter, S. Kappadath, Chao-Jen Lai

Proceedings Volume 5030, (2003) https://doi.org/10.1117/12.480473

KEYWORDS: Chest, Lung, Heart, Signal to noise ratio, Radiography, Sensors, Imaging systems, X-rays, Image quality, X-ray imaging

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Proceedings Article | 22 October 1999 Paper

Coded-aperture x-ray/gamma-ray telescope for arc-minute localization of gamma-ray bursts

Michael Cherry, Peter Altice, David Band, James Buckley, T. Gregory Guzik, Paul Hink, S. Kappadath, John Macri, James Matteson, Mark McConnell, Terrence O'Neill, James Ryan, Kimberly Slavis, John Stacy, Allen Zych

Proceedings Volume 3765, (1999) https://doi.org/10.1117/12.366533

KEYWORDS: Sensors, Charge-coupled devices, Gamma radiation, Telescopes, Spatial resolution, Photons, X-rays, Hard x-rays, Photomasks, Scintillators

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Proceedings Article | 22 October 1999 Paper

Beam test results for the FiberGLAST instrument

Robert Mallozzi, Richard Kippen, Geoffrey Pendleton, William Paciesas, Georgia Richardson, Surasak Phengchamnan, Gerald Karr, Donald Wallace, Gerald Fishman, Thomas Parnell, Robert Wilson, Mark Christl, W. Robert Binns, Paul Hink, Martin Israel, Keith Rielage, John Epstein, Paul Dowkontt, James Buckley, James Ryan, John Macri, Mark McConnell, Tumay Tumer, Michael Cherry, T. Gregory Guzik, John Stacy, S. Kappadath, Muzaffer Atac, Katsushi Arisaka, David Cline, Yuriy Pischalnikov

Proceedings Volume 3765, (1999) https://doi.org/10.1117/12.366510

KEYWORDS: Sensors, Gamma radiation, Particles, Scintillators, Space telescopes, Charge-coupled devices, Monte Carlo methods, Optical simulations, Spatial resolution, Photomultipliers

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Proceedings Article | 19 October 1999 Paper

Development and testing of a fiber/multianode photomultiplier system for use on FiberGLAST

Keith Rielage, Katsushi Arisaka, Muzaffer Atac, W. Robert Binns, James Buckley, Michael Cherry, Mark Christl, David Cline, Paul Dowkontt, John Epstein, Gerald Fishman, T. Gregory Guzik, Paul Hink, Martin Israel, S. Kappadath, Gerald Karr, Richard Kippen, Daniel Leopold, Mark McConnell, John Macri, Robert Mallozzi, William Paciesas, Thomas Parnell, Geoffrey Pendleton, Surasak Phengchamnan, Yuriy Pischalnikov, Georgia Richardson, James Ryan, John Stacy, Tumay Tumer, Gerald Visser, Donald Wallace, Robert Wilson

Proceedings Volume 3768, (1999) https://doi.org/10.1117/12.366579

KEYWORDS: Sensors, Prototyping, Photomultipliers, Electronics, Amplifiers, Gamma radiation, Particles, Logic, Physics, Data acquisition

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Showing 5 of 10 publications

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