Content of Lectures, Tutorials and Practicals

LECTURES

Medical Imaging/Therapy (by Hélène Elleaume)

• Imaging

o K-edge imaging

o Angiography

 Gadolinium / Iodine

 Clinical trials

o Computed tomography

 Cerebral blood volume and blood flow

 Bronchography

• Radiotherapy

o High Z enhanced SSRT

o Iodine pre-clinical trials

• Dosimetry

o Imaging for dosimetry - 3D Gel polymer

o Monte Carlo calculations

X-ray Microscopy (by Chris Jacobsen)

This lecture will discuss further aspects of x-ray imaging. The basic coherence requirements for full-field and scanning microscopy will be reviewed, and examples of synchrotron optical layouts for each will be discussed. Studies aimed at different information (density versus elemental versus chemical content, surface versus internal structure) require different aproaches, and examples of imaging approaches not yet covered (such as soft x-ray scanning microscopes, and lens-based x-ray tomography) will be described. To what resolution can one push these x-ray imaging approaches? Radiation damage often sets a limit, as will be discussed. How might one minimize damage and maximize resolution? By dispensing with x-ray optics entirely and attempting to form x-ray images from far-field diffraction measurements alone in an approach called x-ray diffraction microscopy which requires iterative phasing methods. These approaches to x-ray microscopy will be illustrated with examples drawn from a variety of scientific investigations.

Imaging and Spectromicroscopy with soft X-rays (by Maya Kiskinova)

The element specific photoelectron emission microscopy (µ-XPS and µ-XANES) developed recently at the soft x-ray synchrotron light sources respond the technological demand to have an access to chemical composition, electronic structure, magnetization and fluctuations in these properties at solid surfaces and interfaces [1]. The introductory part of the lecture will summarise the major characteristic parameters of the imaging (XPEEM) and scanning (SPEM) instruments, which manifest the advantages and disadvantages of each of these two approaches. The major part of the lecture will be focused on the potential of SPEM and XPEEM in chemical imaging and micro-spot photoemission spectroscopy. Among the selected research topics are recent achievements in characterization of heterogeneities at surfaces and interfaces, illustrated by selected results obtained using a combination of imaging and spectroscopic modes. [1] S. Günther, B. Kaulich, L. Gregoratti and M. Kiskinova, Prog. Surf. Sci. 70 (2002) 187 and references therein.

Image processing and analysis (by Chris Jacobsen)

This lecture will concentrate on two aspects of x-ray image analysis. Fourier optics approaches can be used to analyze and enhance the spatial content of images, and to recover phase information from intensity measurements. In spectromicroscopy, multivariate statistical methods can be used to uncover the elemental or chemical organization of a specimen and deliver maps of its constituents. This lecture will provide the background needed to use these approaches for image and spectromicroscopy data analysis.

TUTORIALS

Image processing/analysis (by Chris Jacobsen)

This tutorial will provide an opportunity to explore some of the concepts discussed in the corresponding lecture. A scanning microscope image with noise will be analyzed for image enhancement, resolution determination, and deconvolution. Far-field diffraction data will be iteratively reconstructed to obtain a real-space image. Soft x-ray spectromicroscopy data will be analyzed to reveal the number of distinctive spectroscopic signatures and their location within a specimen. Students are encouraged to use their own laptop computers to carry out these examples using code written to work either in the IDL virtual machine (download from www.rsinc.com) or using the Linux/Mac OS X or Cygwin (www.cygwin.com) unix-like environment within Microsoft Windows.

3D image reconstruction and processing tutorial (3h) (by Elodie Boller)

The “filtered back projection” algorithm is usually used, when performing microtomography, to obtain a reconstructed 3D image from about 1000 radiographs recorded during a scan. During the practical an effective 3D reconstruction will be carried out. In addition the importance of different parameters (number of projections, acquisition time, number of views,…) and filters will be tested, in order to understand how to optimize the image acquisition and obtain the best 3D images.

PRACTICALS

ID 17 Medical Imaging/Therapy (by Hélène Elleaume)

• Beam tuning at the Iodine K-edge

• K-edge Angiography

o Coronary artery phantom filled with iodine solution in water

o Retrieve the iodine and tissue mass thickness.

• K-edge or temporal subtraction Computed Tomography

o Center of rotation o Lucite Phantom filled with various iodine concentrations

o Measure the iodine concentration – Detection level / X-ray dose