Dr. Abdollah Pil-Ali Profile

Dr. Abdollah Pil-Ali

at Univ of Waterloo

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Author

Publications (12)

Proceedings Article | 1 April 2024 Presentation + Paper

Kidney stone compositional analysis and identification using a benchtop high-resolution multi-modal x-ray phase-contrast micro-CT imaging system

Abdollah Pil-Ali, Zachary Birch, Sahar Adnani, Chris Scott, Karim Karim

Proceedings Volume 12925, 129250K (2024) https://doi.org/10.1117/12.3005886

KEYWORDS: X-rays, X-ray imaging, Renal calculi, Imaging systems, X-ray detectors, Signal attenuation, Scattering, Minerals, Calcium, Phosphates

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Proceedings Article | 1 April 2024 Poster + Paper

Enhancing temporal performance of a-Se detectors using a low-temperature hole-blocking bilayer design

Sahar Adnani, Abdollah Pil-Ali, Karim Karim

Proceedings Volume 12925, 1292538 (2024) https://doi.org/10.1117/12.3009196

KEYWORDS: Dark current, Sensors, Electrodes, Selenium, X-rays, Design, Baking, Interfaces, X-ray detectors, Mammography

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Proceedings Article | 7 April 2023 Presentation + Paper

Multimodal single-shot x-ray phase-contrast imaging using a high-resolution micropillar-based grating

Abdollah Pil-Ali, Serena Qinyun Shi, Sahar Adnani, Peter Noël, Karim Karim

Proceedings Volume 12463, 1246309 (2023) https://doi.org/10.1117/12.2655809

KEYWORDS: X-rays, X-ray imaging, X-ray detectors, Imaging systems, Silicon, Absorption, Particles, Electroplating

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Grating-based X-ray phase-contrast imaging (XPCi) systems offer higher sensitivity compared to other XPCi methods; however, realizing a high-resolution, compact, dose-efficient imaging system has been a significant challenge from technological and practical points of view until now. X-ray gratings quality and characteristics directly determine the final imaging quality, where a proper grating fabrication process can potentially minimize image artifacts and increase the system visibility. To achieve a high-resolution, compact, dose-efficient XPCi system, high-resolution detectors and high-resolution X-ray absorption gratings are a must. Moreover, an efficient image processing method is required to retrieve multimodal XPCi information—transmission, refraction (phase-contrast), and dark-field—efficiently and simultaneously. In this work, we report on a compact XPCi system that enables multimodal information retrieval through single-shot imaging with two-directional sensitivity. We first present an elegant cost-effective fabrication method to make high-resolution micropillar-based X-ray absorption gratings. A prototype 2D grating is fabricated with micropillars with 4 μm in diameter, periodicity of 16.3 μm, and aspect ratio of more than 40. This grating is then employed along with a prototype hybrid a-Se/CMOS direct conversion high-resolution X-ray detector with a pixel pitch of 8 μm in a compact system with a polychromatic microfocus source to perform X-ray phase-contrast imaging of various samples. We successfully demonstrate a single-shot XPCi and retrieve multimodal XPCi data with transmission and dark-field metrics. The final system is a promising candidate for XPCi applications as it facilitates single-shot imaging, which reduces the exposure dose on samples and yields multimodal XPCi images efficiently, all in a compact bench-top setup. The delivered X-ray dose at the sample, resolution of the system, and compactness of the reported imaging setup are potentially beneficial for ex vivo, in vivo, and computed tomography (CT) imaging applications.

Proceedings Article | 4 April 2022 Presentation + Paper

Investigation of position linearity in position-sensitive microstrip amorphous selenium-based detector

Sahar Adnani, Abdollah Pil-Ali, Celal Con, Karim Karim

Proceedings Volume 12031, 120310M (2022) https://doi.org/10.1117/12.2613306

KEYWORDS: Sensors, Electrodes, Photons, Single photon emission computed tomography, Spatial resolution, Light sources, Signal detection, Selenium, Scintillators

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Proceedings Article | 4 April 2022 Poster + Presentation + Paper

A low-power linear-logarithmic CMOS image sensor

Hamid Reza Yaghobi, Abdollah Pil-Ali, Mohammad Azim Karami

Proceedings Volume 12031, 120314O (2022) https://doi.org/10.1117/12.2613067

KEYWORDS: Transistors, Photodiodes, CMOS sensors, Monte Carlo methods, Sensors, Image sensors, CMOS technology, Charge-coupled devices, Capacitors, Active sensors

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Proceedings Article | 4 April 2022 Poster + Presentation + Paper

Self-aligned fabrication of high-aspect ratio high-resolution x-ray gratings

Abdollah Pil-Ali, Sahar Adnani, Pranav Gavirneni, Seokjee Shin, Bahareh Sadeghimakki, Mahla Poudineh, William Wong, Karim Karim

Proceedings Volume 12031, 120313K (2022) https://doi.org/10.1117/12.2613059

KEYWORDS: X-rays, Lithography, Photomasks, X-ray imaging, Electroplating, Ultraviolet radiation, Scanning electron microscopy, Gold, X-ray lithography, Thin films

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Proceedings Article | 4 April 2022 Poster + Presentation + Paper

A novel multi-layer grating structure for x-ray phase-contrast imaging

Abdollah Pil-Ali, Mohammad Soltani, Sahar Adnani, Bo Cui, Karim Karim

Proceedings Volume 12031, 120313J (2022) https://doi.org/10.1117/12.2613038

KEYWORDS: X-rays, X-ray imaging, Gold, X-ray lithography, Ultraviolet radiation, Chromium, Absorption, Lithography, Optical design, Electroplating, Multilayers, Fabrication, Phase contrast, High aspect ratio silicon micromachining

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Proceedings Article | 4 April 2022 Poster + Presentation + Paper

Improving adhesion quality of SU-8 to gold thin film for absorption grating fabrication in x-ray phase-contrast imaging

Abdollah Pil-Ali, Mohammad Soltani, Sahar Adnani, Muhammed Kayaharman, Mahla Poudineh, Bo Cui, Karim Karim

Proceedings Volume 12031, 120313M (2022) https://doi.org/10.1117/12.2613026

KEYWORDS: Phase contrast, Fabrication, Thin films, Gold, X-rays, Absorption, X-ray imaging, Chromium, Electroplating, Thin film coatings, Silicon, Scanning electron microscopy

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Proceedings Article | 15 February 2021 Poster + Presentation + Paper

Challenges of employing a high resolution x-ray detector in a coded-aperture x-ray phase-contrast imaging system

Abdollah Pil-Ali, Sahar Adnani, Christopher Scott, Karim Karim

Proceedings Volume 11595, 115954O (2021) https://doi.org/10.1117/12.2582351

KEYWORDS: X-ray detectors, X-ray imaging, Imaging systems, Absorption, X-rays, Image resolution, Environmental sensing, Sensors, Phase contrast, Mask making

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Proceedings Article | 15 February 2021 Presentation + Paper

Monte Carlo simulation of an amorphous selenium-based multi-layer photon-counting detector for SPECT applications

Sahar Adnani, Abdollah Pil-Ali, Christopher Scott, Karim Karim

Proceedings Volume 11595, 1159515 (2021) https://doi.org/10.1117/12.2582325

KEYWORDS: Sensors, Single photon emission computed tomography, Monte Carlo methods, Photon transport, Photodetectors, Modulation transfer functions, Spatial resolution, Point spread functions, Energy efficiency, Compton scattering

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Proceedings Article | 15 February 2021 Presentation + Paper

Evaluation of edge-illumination and propagation-based x-ray phase contrast imaging methods for high resolution imaging application

Abdollah Pil-Ali, Sahar Adnani, Christopher Scott, Karim Karim

Proceedings Volume 11595, 115951N (2021) https://doi.org/10.1117/12.2582225

KEYWORDS: X-rays, X-ray imaging, Image resolution, X-ray detectors, Visibility, Systems modeling, Sensors, Mammography, Data modeling, Absorption

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Proceedings Article | 16 March 2020 Paper

A comparison of phase retrieval methods for propagation-based contrast x-ray imaging with polychromatic sources

Rhiannon Lohr, Chris Scott, Abdollah Pil-Ali, Karim Karim

Proceedings Volume 11312, 1131251 (2020) https://doi.org/10.1117/12.2544419

KEYWORDS: Phase retrieval, X-ray imaging, Contrast transfer function, X-rays, Absorption, Signal attenuation, Image retrieval, Sensors, Computer simulations, Phase shifts

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Showing 5 of 12 publications

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