IEEE Photonics Society

Boston Photonics Society Chapter

Boston Chapter of the IEEE Photonics Society

Imaging Workshop PDF

Wednesday, April 6, 13, 20, 28*, May 4, 2011, 7:00–9:30 PM (* Thursday April 28th)
Located at MIT Lincoln Laboratory – 244 Wood Street, Lexington, MA, 02420, USA

Thursday
April 28, 2011
7 PM
 

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Coded Aperture Imaging: Many Holes Make Light Work Slides

Dr. Richard Lanza, Massachusetts Institute of Technology, Cambridge, MA

 

Dr. Richard Lanza, Massachusetts Institute of Technology, Cambridge, MA

Abstract:  Imaging of x-rays and neutrons cannot easily be done using either reflection or refraction.  In this case, the most straightforward way of obtaining an image is a pinhole camera. Unfortunately, a single pinhole involves compromises. If the pinhole is small, the object is imaged with good resolution, but the transmitted power is also small, which produces noisy images. Using a larger pinhole increases signal, but at the expense of degraded resolution. The fundamental idea of coded apertures is to increase signal throughput by opening multiple small pinholes— thus retaining resolution—rather than a large one. Since each pinhole of the aperture generates an image of the object on the detector and all projections overlap, the detector does not produce an image directly. However, from the overlapped copies and knowledge of the pinhole locations one can recover a clear image of the object.  For point-like objects, the SNR can improve as much as N1/2 where N is the number of holes, a significant improvement, especially in statistics limited imaging.  Additionally, reconstruction can be used to produce laminographic images to obtain three-dimensional information from a single view.


This talk will give a very brief history of the use of coded apertures and a quick overview of the theory behind them but will concentrate mostly on recent non-traditional applications, such as nuclear medicine imaging and security applications including detection of radioactive sources and nuclear materials at long distance and detection of IEDs by backscattered x-rays.  An interesting complementary technique which will be discussed is the use of coded sources to obtain increased transmission contrast with multiple radiation sources.


Recommended Reading:

Radiological Imaging: The Theory of Image Formation, Detection, and Processing, Barrett and Swindell

Medical Imaging Systems, Albert Macovski

 

Biography:  Dr. Richard C. Lanza is a Senior Research Scientist in the MIT Department of Nuclear Science and Engineering.  His interests are primarily in the area of application of nuclear techniques and development of instrumentation to problems in materials science, medicine and national security.  More recently he has been active in development of new imaging methods for nuclear medicine and also in the problem of detection of illicit materials such as explosives, contraband, and special nuclear materials.  He has recently served on review panels for these areas for the DOE (IN-10), FAA, NIH and the National Academy of Sciences and has been an Expert Advisor to the International Atomic Energy Agency (IAEA) for their programs in Low Cost Methods for Humanitarian Demining and for Application of Nuclear Techniques to Anti-personnel Landmines Identification.   He is the Past Chairman of the IEEE Radiation Instrumentation Steering Committee and was General Chair for the 2009 IEEE Nuclear Science and Medical Imaging Conference.  His current research has been supported by the DoD (TSWG, DTRA), DoE, DHS, DNDO and TSA.


His professional interests include: High speed electronics, nuclear instrumentation, particle and radiation detectors, application of physical instrumentation to medical problems, medical imaging, computerized tomography (CAT), image reconstruction, application of imaging techniques to non-destructive testing and evaluation, neutron radiography, neutron tomography, applications of nuclear and x-ray techniques to aviation security, land mine detection and characterization technologies and strategies, accelerator based isotope production, applications of tomography to metal processing and production, neutron phase-contrast imaging, remote sensing and standoff detection for nuclear materials, nuclear forensics, and development of novel radiation detectors.


He has more than 150 papers published in these areas and has been awarded 18 patents.


He holds an AB degree from Princeton and SM and PhD degrees from the University of Pennsylvania, all in Physics.

 


For more information on the technical content of the workshop, contact either:
1) Farhad Hakimi (fhakimi@ieee.org), Imaging Workshop Committee Co-Chair
2) William Nelson (w.nelson@ieee.org), Imaging Workshop Committee Co-Chair
3) Reuel Swint (swint@ieee.org), Imaging Workshop Committee Co-Chair
4) Robert Stephenson (Robert.Stephenson@ieee.org), Boston Photonics Society Chair