Dr. Ian A. Cunningham Profile

Dr. Ian A. Cunningham

Scientist at Robarts Research Institute

SPIE Involvement:

Author | Instructor

Publications (50)

Proceedings Article | 14 March 2019

Frequency-dependent MTF and DQE of photon-counting x-ray imaging detectors (Conference Presentation)

Jesse Tanguay, Nicholas Mantella, Ian Cunningham

Proc. SPIE. 10948, Medical Imaging 2019: Physics of Medical Imaging

KEYWORDS: Photodetectors, Sensors, X-rays, Physics, Image sensors, Modulation transfer functions, X-ray imaging, X-ray detectors, Performance modeling, X-ray technology

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Proceedings Article | 1 March 2019

Performance evaluation of a Se/CMOS prototype x-ray detector with the Apodized Aperture Pixel (AAP) design

Tomi Nano, Christopher Scott, Yunzhe Li, Celal Con, Karim Karim, Ian Cunningham

Proc. SPIE. 10948, Medical Imaging 2019: Physics of Medical Imaging

KEYWORDS: Signal to noise ratio, Sensors, Photons, X-rays, Modulation transfer functions, X-ray imaging, Selenium, X-ray detectors, Signal detection, Prototyping

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Proceedings Article | 1 March 2019

Cascaded-systems analysis of signal and noise in contrast-enhanced spectral mammography using amorphous selenium photon-counting field-shaping multi-well avalanche detectors (SWADs)

Jesse Tanguay, Nick Mantella, Jann Stavro, Ian Cunningham, Amir Goldan, Wei Zhao

Proc. SPIE. 10948, Medical Imaging 2019: Physics of Medical Imaging

KEYWORDS: Signal to noise ratio, Photon counting, Sensors, X-rays, Image quality, Iodine, Modulation transfer functions, X-ray imaging, Selenium, X-ray detectors, Signal detection, Systems modeling

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Proceedings Article | 9 March 2018

Cascaded systems analysis of photon-counting field-shaping multi-well avalanche detectors (SWADs)

Jesse Tanguay, Jann Stavro, Dakota McKeown, Amir Goldan, Ian Cunningham, Wei Zhao

Proc. SPIE. 10573, Medical Imaging 2018: Physics of Medical Imaging

KEYWORDS: Photon counting, Imaging systems, Sensors, X-rays, Quantum efficiency, Monte Carlo methods, Modulation transfer functions, Spatial resolution, X-ray imaging, X-ray detectors, Systems modeling, Photon counting theory

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Proceedings Article | 31 March 2016

Detective quantum efficiency: a standard test to ensure optimal detector performance and low patient exposures

Terenz Escartin, Tomi Nano, Ian Cunningham

Proc. SPIE. 9783, Medical Imaging 2016: Physics of Medical Imaging

KEYWORDS: Signal to noise ratio, Spatial frequencies, Sensors, X-rays, Quantum efficiency, Radiography, Sensor performance, Image quality, Image quality, Modulation transfer functions, X-ray imaging, X-ray detectors, X-ray detectors, Image quality standards

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Proceedings Article | 29 March 2016

Theoretical and Monte Carlo optimization of a stacked three-layer flat-panel x-ray imager for applications in multi-spectral diagnostic medical imaging

Sebastian Lopez Maurino, Aldo Badano, Ian Cunningham, Karim Karim

Proc. SPIE. 9783, Medical Imaging 2016: Physics of Medical Imaging

KEYWORDS: Tissues, Imaging systems, Sensors, Photons, X-rays, Scintillators, Radiography, Diagnostics, Medical imaging, Monte Carlo methods, Image quality, X-ray imaging, X-ray detectors, Signal detection, Dual energy imaging

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Proceedings Article | 22 March 2016

A novel x-ray detector design with higher DQE and reduced aliasing: Theoretical analysis of x-ray reabsoprtion in detector converter material

Tomi Nano, Terenz Escartin, Karim Karim, Ian Cunningham

Proc. SPIE. 9783, Medical Imaging 2016: Physics of Medical Imaging

KEYWORDS: Signal to noise ratio, Sensors, Photons, Quantum efficiency, Interference (communication), Image quality, X-ray imaging, Selenium, X-ray detectors

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Proceedings Article | 18 March 2015

Apodized-aperture pixel design to increase high-frequency DQE and reduce noise aliasing in x-ray detectors

Elina Ismailova, Karim Karim, Ian Cunningham

Proc. SPIE. 9412, Medical Imaging 2015: Physics of Medical Imaging

KEYWORDS: CMOS sensors, Spatial frequencies, Sensors, X-rays, Interference (communication), Modulation transfer functions, X-ray imaging, Selenium, X-ray detectors, Signal detection

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Proceedings Article | 18 March 2015

Theoretical and experimental comparison of image signal and noise for dual-energy subtraction angiography and conventional x-ray angiography

Christiane Burton, John Mayo, I. Cunningham

Proc. SPIE. 9412, Medical Imaging 2015: Physics of Medical Imaging

KEYWORDS: Signal to noise ratio, Quantum wells, Sensors, X-rays, Interference (communication), Iodine, Angiography, Image enhancement, X-ray imaging, X-ray detectors

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Cardiovascular disease is currently the leading cause of mortality worldwide. Digital subtraction angiography (DSA) is widely used to enhance the visibility of small vessels and vasculature obscurred by overlying bone and lung fields by subtracting a mask and contrast image. However, motion between these mask and contrast images can introduce artifacts that can render a study non-diagnostic. This makes DSA particularly unsuccessful for cardiac imaging. A method called dual-energy, or energy subtraction angiography (ESA), was proposed in the past as an alternative for vascular imaging, however it was not pursued because experimental results suggested that image quality was deemed as poor and inferior to DSA. Image quality for angiography comes down to iodine signal and noise. In this paper we investigate the fundamental iodine signal and noise analysis of ESA and compare it to DSA. Method: We developed a polyenergetic and monoenergetic theoretical model for iodine signal and noise for both ESA and DSA. We validated our polyenergetic model by experiment where ESA and DSA images of a vascular phantom were acquired using an x-ray system with a flat panel CsI Xmaru1215CF-MPTM (Rayence Co., Ltd., Republic of Korea) detector. For ESA low and high applied tube voltages of 50 kV and 120 kV (2.5 mmCu), respectively, and for DSA the applied tube voltage was 80 kV. Iodine signal-to-noise ratio (SNR) per entrance exposure was calculated for each iodine concentration for both ESA and DSA. Results: Our measured iodine SNR agreed well with theoretical calculations. Iodine SNR for ESA was relatively higher than DSA for low iodine mass loadings, and as iodine mass loading increases iodine SNR decreases. Conclusions: We have developed a model for iodine SNR for both DSA and ESA. Our model was validated with experiment and showed excellent agreement. We have shown that there is potential for obtaining iodine-specific images using ESA that are similar to DSA.

Proceedings Article | 18 March 2015

Signal and noise analysis of flat-panel sandwich detectors for single-shot dual-energy x-ray imaging

Dong Woon Kim, Ho Kyung Kim, Hanbean Youn, Seungman Yun, Jong Chul Han, Junwoo Kim, Soohwa Kam, Jesse Tanguay, Ian Cunningham

Proc. SPIE. 9412, Medical Imaging 2015: Physics of Medical Imaging

KEYWORDS: Electronics, Sensors, Photons, X-rays, Interference (communication), Photodiodes, Modulation transfer functions, X-ray imaging, X-ray detectors, Signal detection

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Proceedings Article | 17 March 2015

Three-dimensional segmentation of pulmonary artery volume from thoracic computed tomography imaging

Tamas Lindenmaier, Khadija Sheikh, Emma Bluemke, Igor Gyacskov, Marco Mura, Christopher Licskai, Lisa Mielniczuk, Aaron Fenster, Ian Cunningham, Grace Parraga

Proc. SPIE. 9417, Medical Imaging 2015: Biomedical Applications in Molecular, Structural, and Functional Imaging

KEYWORDS: Gold, Medicine, Image segmentation, Arteries, Lung, 3D metrology, Computed tomography, Pulmonary hypertension, Chronic obstructive pulmonary disease, 3D image processing

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Proceedings Article | 17 March 2015

Principal component analysis of the CT density histogram to generate parametric response maps of COPD

Nanxi Zha, Dante P. Capaldi, Damien Pike, David McCormack, Ian Cunningham, Grace Parraga

Proc. SPIE. 9417, Medical Imaging 2015: Biomedical Applications in Molecular, Structural, and Functional Imaging

KEYWORDS: Gold, Principal component analysis, Medicine, X-ray computed tomography, Signal attenuation, Magnetic resonance imaging, Diffusion, Lung, Emphysema, Chronic obstructive pulmonary disease

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Proceedings Article | 17 March 2015

Fourier-based linear systems description of free-breathing pulmonary magnetic resonance imaging

D. Capaldi, S. Svenningsen, I. Cunningham, G. Parraga

Proc. SPIE. 9417, Medical Imaging 2015: Biomedical Applications in Molecular, Structural, and Functional Imaging

KEYWORDS: Signal to noise ratio, Imaging systems, Magnetic resonance imaging, Fourier transforms, Image registration, Lung, Image quality, Systems modeling, Pulmonary function tests, Chronic obstructive pulmonary disease

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Proceedings Article | 19 March 2014

Feasibility of active sandwich detectors for single-shot dual-energy imaging

Seungman Yun, Jong Chul Han, Dong Woon Kim, Hanbean Youn, Ho Kyung Kim, Jesse Tanguay, Ian Cunningham

Proc. SPIE. 9033, Medical Imaging 2014: Physics of Medical Imaging

KEYWORDS: Tissues, Sensors, Photons, X-rays, Copper, Monte Carlo methods, Image quality, Aluminum, X-ray imaging, X-ray detectors

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Proceedings Article | 19 March 2014

Amorphous selenium direct detection CMOS digital x-ray imager with 25 micron pixel pitch

Christopher Scott, Shiva Abbaszadeh, Sina Ghanbarzadeh, Gary Allan, Michael Farrier, Ian Cunningham, Karim Karim

Proc. SPIE. 9033, Medical Imaging 2014: Physics of Medical Imaging

KEYWORDS: Gold, CMOS sensors, Imaging systems, Sensors, X-rays, Modulation transfer functions, Spatial resolution, X-ray imaging, Selenium, X-ray detectors

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Proceedings Article | 19 March 2013

Cascaded-systems analyses of the DQE of double-Z x-ray detectors including photoelectric, coherent and incoherent interactions

Seungman Yun, Jesse Tanguay, Ho Kyung Kim, Ian Cunningham

Proc. SPIE. 8668, Medical Imaging 2013: Physics of Medical Imaging

KEYWORDS: Scattering, Sensors, Chemical species, X-rays, Interference (communication), Monte Carlo methods, Modulation transfer functions, X-ray detectors, Signal detection, Absorption

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Image quality in diagnostic x-ray detectors is limited by statistical properties governing how, and where, x-ray energy is deposited in a detector. This in turn depends on the physics of underlying x-ray interactions, and the development of theoretical models of x-ray interaction physics is therefore a critical step in optimal detector design and assessment. While cascaded-systems analyses are often used to describe image signal and noise in many systems, it has always been assumed there is only a single element (single Z) with which all x rays interact even though most commonly used and promising candidates are compound materials. In addition, coherent and incoherent scattering and their effects on image quality are usually ignored but may be important in some situa- tion such as in low-Z atoms with high x-ray energies. We present a theoretical model of energy deposition within a double-Z x-ray detector material that addresses the nature of energy absorption following photoelectric and incoherent interactions and the effects of coherent scatter prior to energy deposition by photoelectric interactions. A cascaded systems approach is used to describe the transfer of signal and noise in terms of the modulation transfer function (MTF), Wiener noise power spectrum (NPS), and detective quantum efficiency (DQE). The model is validated by comparing Monte Carlo simulation results with CsI and PbI2 double-Z materials. Excellent agreement is obtained for each metric over the entire diagnostic energy range up to 10 cycles/mm. It is shown that in all cases tested, a combination of two single-Z models weighted by the atomic density of each atom type gives equivalent results to the more comprehensive double-Z model within a few percent. This result suggests the simpler model is adequate and may be preferred for the optimal design of conventional radiography detectors and the estimation of x-ray imaging performance of novel photoconductor materials.

Proceedings Article | 19 March 2013

Cascaded-systems analyses of photon-counting x-ray detectors

Jesse Tanguay, Seungman Yun, Ho Kyung Kim, Ian Cunningham

Proc. SPIE. 8668, Medical Imaging 2013: Physics of Medical Imaging

KEYWORDS: Sensors, Photons, X-rays, Interference (communication), Bismuth, X-ray imaging, Selenium, X-ray detectors, Signal detection, Stochastic processes

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Proceedings Article | 6 March 2013

Characterization of a digital x-ray detector for region of interest tuberculosis screening

Ryan Mann, Ian Cunningham, Karim Karim

Proc. SPIE. 8668, Medical Imaging 2013: Physics of Medical Imaging

KEYWORDS: Amorphous silicon, Chest, Imaging systems, Sensors, X-rays, Radiography, Diagnostics, Modulation transfer functions, X-ray detectors, Chest imaging

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Proceedings Article | 9 March 2012

Extension of cascaded systems analysis to single-photon-counting x-ray detectors

Jesse Tanguay, Seungman Yun, Ho Kyung Kim, Ian Cunningham

Proc. SPIE. 8313, Medical Imaging 2012: Physics of Medical Imaging

KEYWORDS: Radon, Imaging systems, Sensors, Image processing, Interference (communication), Medical imaging, Signal processing, X-ray imaging, X-ray detectors, Signal detection

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Proceedings Article | 9 March 2012

A robust approach to measuring the detective quantum efficiency of radiographic detectors in a clinical setting

Michael McDonald, H. Kim, J. Henry, I. Cunningham

Proc. SPIE. 8313, Medical Imaging 2012: Physics of Medical Imaging

KEYWORDS: Sensors, Image processing, X-rays, Copper, Quantum efficiency, Data processing, Image enhancement, Modulation transfer functions, X-ray detectors, Signal detection

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Proceedings Article | 17 March 2011

A novel method to measure the zero-frequency DQE of a non-linear imaging system

Michael McDonald, Ho Kyung Kim, John Henry, Ian Cunningham

Proc. SPIE. 7961, Medical Imaging 2011: Physics of Medical Imaging

KEYWORDS: Imaging systems, Spatial frequencies, Sensors, Image processing, Copper, Quantum efficiency, Physics, Medical imaging, X-ray detectors, Current controlled current source

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Proceedings Article | 16 March 2011

The case for single-exposure angiography using energy-resolving photon-counting detectors: a theoretical comparison of signal and noise with conventional subtraction angiography

Jesse Tanguay, Ho Kyung Kim, Ian Cunningham

Proc. SPIE. 7961, Medical Imaging 2011: Physics of Medical Imaging

KEYWORDS: Photodetectors, Sensors, X-rays, Interference (communication), Iodine, Angiography, Artificial intelligence, X-ray imaging, X-ray detectors, Signal detection

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Proceedings Article | 23 March 2010

Modeling of pulse signals in photon-counting detectors

Chang Hwy Lim, Okla Joe, Ian Cunningham, Ho Kyung Kim

Proc. SPIE. 7622, Medical Imaging 2010: Physics of Medical Imaging

KEYWORDS: Semiconductors, Photodetectors, Sensors, X-rays, Amplifiers, Photonics systems, Signal processing, Signal generators, Signal detection, Digital x-ray imaging

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Proceedings Article | 23 March 2010

Phosphor-filled micro-well arrays for digital x-ray imaging: effects of surface treatments

Seungman Yun, Chang Hwy Lim, Tae Woo Kim, Ian Cunningham, Thorsten Achterkirchen, Ho Kyung Kim

Proc. SPIE. 7622, Medical Imaging 2010: Physics of Medical Imaging

KEYWORDS: Silica, Sensors, Photons, X-rays, Silicon, Scintillators, Quantum efficiency, Reflectivity, Photodiodes, Modulation transfer functions

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Proceedings Article | 23 March 2010

An aging study of the signal and noise characteristics in large-area CMOS detectors

Jong Chul Han, Seungman Yun, Chang Hwy Lim, Tae Gyun Youm, Sung Kyn Heo, Tae Woo Kim, Ian Cunningham, Ho Kyung Kim

Proc. SPIE. 7622, Medical Imaging 2010: Physics of Medical Imaging

KEYWORDS: CMOS sensors, Sensors, X-rays, Interference (communication), Photodiodes, Image analysis, Image quality, Image sensors, Modulation transfer functions, Signal detection

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Proceedings Article | 22 March 2010

Noise in energy-discriminating photon-counting x-ray imaging detectors

Jesse Tanguay, Ho Kyung Kim, Ian Cunningham

Proc. SPIE. 7622, Medical Imaging 2010: Physics of Medical Imaging

KEYWORDS: Imaging systems, Sensors, X-rays, Interference (communication), Image sensors, Signal processing, X-ray imaging, Selenium, X-ray detectors, Signal detection

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Proceedings Article | 18 March 2008

Temporal modulation transfer function of fluoroscopic systems: small-signal versus large-signal approaches

S. Friedman, I. Cunningham

Proc. SPIE. 6913, Medical Imaging 2008: Physics of Medical Imaging

KEYWORDS: Point spread functions, Imaging systems, Sensors, Signal attenuation, X-rays, Copper, Quantum efficiency, Precision measurement, Modulation transfer functions, X-ray imaging

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Proceedings Article | 18 March 2008

Use of the detective quantum efficiency in a quality assurance program

I. Cunningham

Proc. SPIE. 6913, Medical Imaging 2008: Physics of Medical Imaging

KEYWORDS: Chest, Imaging systems, Spatial frequencies, Sensors, X-rays, Quantum efficiency, Medical imaging, Image quality, Modulation transfer functions, X-ray imaging

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Proceedings Article | 13 March 2007

Development of a portable instrument for automated measurements of the detective quantum efficiency of x-ray detectors

I. Cunningham, S. Lazarev, M. Sattarivand, N. Jankovic

Proc. SPIE. 6510, Medical Imaging 2007: Physics of Medical Imaging

KEYWORDS: Imaging systems, Spatial frequencies, Sensors, X-rays, Quantum efficiency, Manufacturing, Modulation transfer functions, X-ray imaging, X-ray detectors, Prototyping

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Proceedings Article | 2 March 2006

A method to measure the temporal MTF to determine the DQE of fluoroscopy systems

S. Friedman, I. Cunningham

Proc. SPIE. 6142, Medical Imaging 2006: Physics of Medical Imaging

KEYWORDS: Point spread functions, Sensors, Video, X-rays, Quantum efficiency, Data acquisition, Image intensifiers, Modulation transfer functions, Fluoroscopy, X-ray imaging

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Proceedings Article | 20 April 2005

Comparison of air space measurement imaged by CT, small-animal CT, and hyperpolarized Xe MRI

Aniseh Madani, Steven White, Giles Santyr, Ian Cunningham

Proc. SPIE. 5745, Medical Imaging 2005: Physics of Medical Imaging

KEYWORDS: Optical spheres, Tissues, Magnetic resonance imaging, Image processing, Medical research, Lung, Xenon, Solids, Computed tomography, Spherical lenses

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