Dr. Bradley E. Patt Profile

Dr. Bradley E. Patt

Co-Founder, President and CEO at EVO LLC

SPIE Involvement:

Author

Publications (23)

Proceedings Article | 15 September 2011 Paper

Dose reduction in molecular breast imaging

Douglas Wagenaar, Samir Chowdhury, James Hugg, Rex Moats, Bradley Patt

Proc. SPIE. 8143, Medical Applications of Radiation Detectors

KEYWORDS: Breast, Breast cancer, Cameras, Sensors, Collimators, Head, Near field, Mammography, Lead, Breast imaging

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Proceedings Article | 15 September 2011 Paper

High-performance imaging of stem cells using single-photon emissions

Douglas Wagenaar, Rex Moats, Neal Hartsough, Dirk Meier, James Hugg, Tang Yang, Dan Gazit, Gadi Pelled, Bradley Patt

Proc. SPIE. 8143, Medical Applications of Radiation Detectors

KEYWORDS: Gold, Microscopes, Sensors, Calibration, Microscopy, Silicon, Gamma radiation, Stem cells, In vivo imaging, Coded apertures

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Proceedings Article | 17 March 2011 Paper

Basic design and simulation of a SPECT microscope for in vivo stem cell imaging

Rex Moats, Yang Tang, James Hugg, Dirk Meier, David Koos, Neal Hartsough, Bradley Patt, Douglas Wagenaar

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

KEYWORDS: Gold, Microscopes, Imaging systems, Sensors, Silicon, Image resolution, Stem cells, In vivo imaging, Coded apertures, Coded aperture imaging

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Proceedings Article | 16 March 2011 Paper

Design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals

Benjamin M. Tsui, James Hugg, Jingyan Xu, Si Chen, Dirk Meier, William Edelstein, Abdel El-Sharkawy, Douglas Wagenaar, Bradley Patt

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

KEYWORDS: Imaging systems, Sensors, Magnetic resonance imaging, Image restoration, Data acquisition, Collimators, Spatial resolution, Single photon emission computed tomography, Prototyping, Preclinical imaging

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Proceedings Article | 16 March 2011 Paper

Material separation in x-ray CT with energy resolved photon-counting detectors

X. Wang, D. Meier, K. Taguchi, D. Wagenaar, B. Patt, E. Frey

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

KEYWORDS: Photodetectors, Polymethylmethacrylate, X-ray computed tomography, Sensors, Signal attenuation, X-rays, Iodine, Gadolinium, X-ray detectors, Absorption

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Proceedings Article | 19 March 2010 Paper

SPECT data acquisition and image reconstruction in a stationary small animal SPECT/MRI system

Jingyan Xu, Si Chen, Jianhua Yu, Dirk Meier, Douglas Wagenaar, Bradley Patt, Benjamin M. Tsui

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

KEYWORDS: Point spread functions, Sensors, Magnetic resonance imaging, Matrices, Image restoration, Image resolution, Tomography, Data acquisition, Collimators, Single photon emission computed tomography

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The goal of the study was to investigate data acquisition strategies and image reconstruction methods for a stationary SPECT insert that can operate inside an MRI scanner with a 12 cm bore diameter for simultaneous SPECT/MRI imaging of small animals. The SPECT insert consists of 3 octagonal rings of 8 MR-compatible CZT detectors per ring surrounding a multi-pinhole (MPH) collimator sleeve. Each pinhole is constructed to project the field-of-view (FOV) to one CZT detector. All 24 pinholes are focused to a cylindrical FOV of 25 mm in diameter and 34 mm in length. The data acquisition strategies we evaluated were optional collimator rotations to improve tomographic sampling; and the image reconstruction methods were iterative ML-EM with and without compensation for the geometric response function (GRF) of the MPH collimator. For this purpose, we developed an analytic simulator that calculates the system matrix with the GRF models of the MPH collimator. The simulator was used to generate projection data of a digital rod phantom with pinhole aperture sizes of 1 mm and 2 mm and with different collimator rotation patterns. Iterative ML-EM reconstruction with and without GRF compensation were used to reconstruct the projection data from the central ring of 8 detectors only, and from all 24 detectors. Our results indicated that without GRF compensation and at the default design of 24 projection views, the reconstructed images had significant artifacts. Accurate GRF compensation substantially improved the reconstructed image resolution and reduced image artifacts. With accurate GRF compensation, useful reconstructed images can be obtained using 24 projection views only. This last finding potentially enables dynamic SPECT (and/or MRI) studies in small animals, one of many possible application areas of the SPECT/MRI system. Further research efforts are warranted including experimentally measuring the system matrix for improved geometrical accuracy, incorporating the co-registered MRI image in SPECT reconstruction, and exploring potential applications of the simultaneous SPECT/MRI SA system including dynamic SPECT studies.

Proceedings Article | 19 March 2010 Paper

Microcomputed tomography with a second generation photon-counting x-ray detector: contrast analysis and material separation

X. Wang, D. Meier, P. Oya, G. Maehlum, D. Wagenaar, B. M. Tsui, B. Patt, E. Frey

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

KEYWORDS: Photodetectors, Polymethylmethacrylate, Sensors, Signal attenuation, Photons, X-rays, Bone, Iodine, Gadolinium, X-ray detectors

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Proceedings Article | 14 March 2009 Paper

Enhanced discrimination of calcified and soft arterial plaques using computed tomography with a multi-energy-window photon counting x-ray detector

Xiaolan Wang, Jingyan Xu, Katsuyuki Taguchi, Bradley Patt, Douglas Wagenaar, Eric Frey

Proc. SPIE. 7258, Medical Imaging 2009: Physics of Medical Imaging

KEYWORDS: Signal to noise ratio, Photon counting, Tissues, Sensors, Blood, X-rays, Calcium, Arteries, Iodine, X-ray detectors

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Proceedings Article | 28 September 2007 Paper

Advantages of semiconductor CZT for medical imaging

Douglas Wagenaar, Kevin Parnham, Bjorn Sundal, Gunnar Maehlum, Samir Chowdhury, Dirk Meier, Thor Vandehei, Marek Szawlowski, Bradley Patt

Proc. SPIE. 6707, Penetrating Radiation Systems and Applications VIII

KEYWORDS: Semiconductors, Imaging systems, Cameras, Sensors, Image resolution, Medical imaging, Tomography, Spatial resolution, Single photon emission computed tomography, Positron emission tomography

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Proceedings Article | 15 March 2007 Paper

Microcomputed tomography with a photon-counting x-ray detector

E. Frey, K. Taguchi, M. Kapusta, J. Xu, T. Orskaug, I. Ninive, D. Wagenaar, B. Patt, B. Tsui

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

KEYWORDS: Signal to noise ratio, Photodetectors, Photon counting, X-ray computed tomography, Tissues, Sensors, X-rays, Microcomputed tomography, X-ray imaging, X-ray detectors

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Proceedings Article | 26 October 2004 Paper

Gated cardiac SPECT in rodents using a dedicated SPECT system: X-SPECT

Thor Vandehei, J. Li, Koji Iwata, Bradley Patt, G. Caravaglia, Neal Hartsough, Bruce Hasegawa, Benjamin Tsui

Proc. SPIE. 5541, Penetrating Radiation Systems and Applications VI

KEYWORDS: Imaging systems, Cameras, Sensors, Heart, Data acquisition, Collimators, Spatial resolution, Motion measurement, Single photon emission computed tomography, Expectation maximization algorithms

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Proceedings Article | 26 October 2004 Paper

Mercuric iodide polycrystalline films on cylindrical substrates

Neal Hartsough, Jan Iwanczyk, Nathan Skinner, Larry Franks, Bradley Patt, Marek Szawlowski

Proc. SPIE. 5541, Penetrating Radiation Systems and Applications VI

KEYWORDS: Sensors, Spectroscopy, Particles, Crystals, X-rays, Spectrometers, Silicon, Scintillators, Gamma radiation, Signal detection

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Proceedings Article | 20 January 2004 Paper

Vortex: a new high-performance silicon multicathode detector for XRD and XRF applications

Liangyuan Feng, Jan Iwanczyk, Bradley Patt, Shaul Barkan, Carolyn Tull

Proc. SPIE. 5198, Hard X-Ray and Gamma-Ray Detector Physics V

KEYWORDS: Diffraction, Sensors, Microchannel plates, X-rays, Copper, X-ray diffraction, Silicon, Capacitance, Field effect transistors, Optical character recognition

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Proceedings Article | 26 November 2002 Paper

Evaluation of x-ray detectors for dual-modality CT-SPECT animal imaging

Lawrence MacDonald, Koji Iwata, Bradley Patt, Jan Iwanczyk, Andrew Hwang, Max Wu, Bruce Hasegawa

Proc. SPIE. 4786, Penetrating Radiation Systems and Applications IV

KEYWORDS: X-ray computed tomography, Imaging systems, Sensors, Scanners, X-rays, X-ray sources, Spatial resolution, X-ray imaging, X-ray detectors, Single photon emission computed tomography

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Proceedings Article | 26 November 2002 Paper

Evaluation of handheld gamma camera with 1-mm NaI(T1) pixels

Yuko Yamaguchi, Lawrence MacDonald, Bradley Patt, Jan Iwanczyk, John Aarsvold, Robert Mintzer, Naomi Alazraki, Carmen Greene

Proc. SPIE. 4786, Penetrating Radiation Systems and Applications IV

KEYWORDS: Surgery, Cameras, Sensors, Image processing, Crystals, Scintillators, Collimators, Spatial resolution, Prototyping, Lymphatic system

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Proceedings Article | 19 December 2001 Paper

Avalanching silicon drift photodetector (A+SDP)

Gintas Vilkelis, Bradley Patt, Jan Iwanczyk, Lawrence MacDonald, Carolyn Tull

Proc. SPIE. 4508, Penetrating Radiation Systems and Applications III

KEYWORDS: Photodetectors, Electronics, Avalanche photodetectors, Sensors, Electrodes, Silicon, Scintillators, Capacitance, Field effect transistors, Gamma radiation

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Proceedings Article | 19 December 2001 Paper

Intravascular probe for detection of vulnerable plaque

Bradley Patt, Jan Iwanczyk, Lawrence MacDonald, Yuko Yamaguchi, Carolyn Tull, Martin Janecek, Edward Hoffman, H. William Strauss, Ross Tsugita, Vartan Ghazarossian

Proc. SPIE. 4508, Penetrating Radiation Systems and Applications III

KEYWORDS: Optical fibers, Imaging systems, Sensors, Interfaces, Scintillators, Arteries, Image sensors, Angiography, Scintillation, Floods

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Coronary angiography is unable to define the status of the atheroma, and only measures the luminal dimensions of the blood vessel, without providing information about plaque content. Up to 70% of heart attacks are caused by minimally obstructive vulnerable plaques, which are too small to be detected adequately by angiography. We have developed an intravascular imaging detector to identify vulnerable coronary artery plaques. The detector works by sensing beta or conversion electron radiotracer emissions from plaque-binding radiotracers. The device overcomes the technical constraints of size, sensitivity and conformance to the intravascular environment. The detector at the distal end of the catheter uses six 7mm long by 0.5mm diameter scintillation fibers coupled to 1.5m long plastic fibers. The fibers are offset from each other longitudinally by 6mm and arranged spirally around a guide wire in the catheter. At the proximal end of the catheter the optical fibers are coupled to an interface box with a snap on connector. The interface box contains a position sensitive photomultiplier tube (PSPMT) to decode the individual fibers. The whole detector assembly fits into an 8-French (2.7 mm in diameter) catheter. The PSPMT image is further decoded with software to give a linear image, the total instantaneous count rate and an audio output whose tone corresponds to the count rate. The device was tested with F-18 and Tl-204 sources. Spectrometric response, spatial resolution, sensitivity and beta to background ratio were measured. System resolution is 6 mm and the sensitivity is >500 cps / micrometers Ci when the source is 1 mm from the detector. The beta to background ratio was 11.2 for F-18 measured on a single fiber. The current device will lead to a system allowing imaging of labeled vulnerable plaque in coronary arteries. This type of signature is expected to enable targeted and cost effective therapies to prevent acute coronary artery diseases such as: unstable angina, acute myocardial infarction, and sudden cardiac death.

Proceedings Article | 19 December 2001 Paper

Mercuric iodide polycrystalline films

Jan Iwanczyk, Bradley Patt, Carolyn Tull, Lawrence MacDonald, Nathan Skinner, Edward Hoffman, Laura Fornaro, Luis Mussio, Edgardo Saucedo, Alvaro Gancharov

Proc. SPIE. 4508, Penetrating Radiation Systems and Applications III

KEYWORDS: Digital photography, Imaging systems, Sensors, Crystals, X-rays, X-ray diffraction, Spatial resolution, X-ray imaging, X-ray detectors, Digital x-ray imaging

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Proceedings Article | 18 December 2001 Paper

Approaching cryogenic Ge performance with Peltier-cooled CdTe

Abdurakhman Khusainov, Jan Iwanczyk, Bradley Patt, Alexandre Pirogov, Duc Vo, Phyllis Russo

Proc. SPIE. 4507, Hard X-Ray and Gamma-Ray Detector Physics III

KEYWORDS: Sensors, Spectroscopy, Crystals, Germanium, Spectrometers, Electrons, Gamma radiation, Plutonium, Electric field sensors, Temperature metrology

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Proceedings Article | 18 December 2000 Paper

High-resolution hand-held gamma camera

Lawrence MacDonald, Bradley Patt, Jan Iwanczyk, Yuko Yamaguchi, David McElroy, Edward Hoffman, John Aarsvold, Robert Mintzer, Naomi Alazraki

Proc. SPIE. 4142, Penetrating Radiation Systems and Applications II

KEYWORDS: Tumors, Surgery, Cameras, Sensors, Image processing, Crystals, Collimators, Scintillation, Spatial resolution, Lymphatic system

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Proceedings Article | 18 December 2000 Paper

Performance evaluation of dedicated compact scintillation cameras

David McElroy, Edward Hoffman, Lawrence MacDonald, Bradley Patt, Jan Iwanczyk, Yuko Yamaguchi

Proc. SPIE. 4142, Penetrating Radiation Systems and Applications II

KEYWORDS: Breast, Liver, Tumors, Cameras, Crystals, Heart, Collimators, Scintillation, Spatial resolution, Standards development

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Proceedings Article | 2 May 2000 Paper

New transparent polycrystalline silicate scintillators

Eric Bescher, Sarah Robson, John Mackenzie, Bradley Patt, Jan Iwanczyk, Edward Hoffman

Proc. SPIE. 3943, Sol-Gel Optics V

KEYWORDS: Fabrication, Transparency, Spectroscopy, Crystals, Scintillators, Scintillation, Gamma radiation, Sol-gels, Lutetium, Silicates

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Proceedings Article | 19 October 1999 Paper

Novel x-ray and gamma-ray drift detectors based on silicon and compound semiconductors

Jan Iwanczyk, Bradley Patt, Carolyn Tull, Lawrence MacDonald

Proc. SPIE. 3768, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics

KEYWORDS: Sensors, Electrodes, X-rays, Silicon, Scintillators, Quantum efficiency, Amplifiers, Gamma radiation, X-ray detectors, Compound semiconductors

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