Nuclear Science Symposium
and
Medical Imaging Conference

Lyon, France
October
15-20, 2000

 

Short courses for NSS-MIC 2000

Chairman for Short Courses:

Short description of the courses

SOLID STATE DETECTORS IN HIGH ENERGY PHYSICS (15 October, 9:00am-5:30pm)
Organizer:Anna Peisert (CERN, Geneva, Switzerland)
Lecturers: Anna Peiser, A. Zalewska (Institut of Nuclear Physics, Cracow, Poland),
Shaun Roe (CERN, Geneva, Switzerland), Walter Snoeys (CERN, Geneva, Switzerland)

Basic properties of detectors:
p-n junction, charge collection, 2-dimensional readout.
Detectors with integrated coupling capacitors and biasing resistors, double metal layer.
New developments: gallium arsenide and diamond detectors.
Readout electronics: CMOS and bipolar technology and devices: general circuit blocks, optimization of a front end for detector readout, radiation tolerance of deep sub-micron technologies.

Use of silicon detectors in large experiments:
Vertex detection, tracking and pattern recognition, calorimetry, physics measurements, application in solid state physics and medicine.

Radiation hardness:
Effects of radiation on silicon; use of silicon detectors at LHC
Evolution of leakage current and depletion voltage with radiation
Radiation resistance of GaAs and diamond detectors.

PARTICLE IDENTIFICATION AT HIGH ENERGIES (15 October, 9:00am- 5:30pm)
Organizer: Peter Krizan (Ljubljana University, Slovenia)
Lecturers: Peter Krizan, Daniel Froidevaux (CERN, Geneva, Switzerland),
Christian Joram (CERN, Geneva, Switzerland)

Introduction: motivations and requirements for PID at high energies,
Hadron identification: methods, overview.
Cherenkov Ring Imaging: resolution, number of photons, design and optics, radiators, alignment, data analysis.
RICH with gas detectors: photoconvertors, photon yield, long term stability, high rate operation, aging and remedies.
RICH with vacuum based detectors: photocathodes, PMT, MAPMT, HPD, exotics.
Integration issues.
Other techniques (TOF, dE/dx in gaseous and solid state devices).
Electron identification: introduction.
Calorimeters: shower shape,granularity, pile-up effects, trigger.
Energy/momentum matching; rejection against photon conversions.
Transition radiation: principle and limitations, example of one application: the ATLAS Transition Radiation Tracker.

DETECTORS FOR X-AND GAMMA-RAY ASTROPHYSICS (15 October, 9:00am - 5:30pm)
Organizer: Elena Aprile (Columbia University, NY, USA)
Lecturers: Elena Aprile, Fiona Harrison (Caltech, USA), Reshmi Mukherjee (Barnard College, NY, USA)

The course will cover detector technologies and methods used or under development for the detection and imaging of gamma-rays from astrophysical sources, both in space and ground-based observations. A serie of four lectures will cover the observational requirements and the techniques relevant to photons of very low (10keV) to very high (10 TeV) energy: imaging techniques in hard x-ray and medium energy gamma-ray astronomy (multi-layers focusing optics, Bragg concentrators and coded apertures); detection techniques for hard X-rays, medium and high energy gamma-rays (solid state detectors, gas and liquid time projection chambers, NaI/CsI calorimeters); imaging techniques in medium/high energy gamma-ray astronomy (Compton and pair production telescopes); detection techniques for very high-energy gamma-rays (atmospheric Cherenkov and extensive air shower telescopes).

ANALYTICAL RECONSTRUCTION METHODS (17 October, 9.00 am - 12:30 am)
Organizer: Pierre Grangeat (CEA/LETI Grenoble, France)
Lecturers: Pierre Grangeat, Michel Defrise (Vrije Universiteit Brussel, Belgium), Frédéric Noo (Université Montéfiore, Liège, Belgium), Prof. Per-Erik Danielsson (Linköping University, Linköping, Sweden)

Analytical reconstruction methods are widely used on tomographic devices such as X-ray CT, SPECT and PET. Their principle is to describe both the image to reconstruct and the measurement as continuous functions and to model the acquisition process by an analytic transform operator. Then, the image reconstruction algorithms are based on the explicit inversion formula of the inverse transform. This direct computation defines faster reconstruction process than iterative algorithms linked to discrete reconstruction methods. In this short course session, we will start from basic principles and then continue with an overview on the most recent fully 3D reconstruction algorithms. This course will be divided into the following 4 lectures.

1. Parallel beam image reconstruction and fully 3D PET (45 mn)
     Michel Defrise, Vrije Universiteit Brussel, Belgium

After a discussion on the general mathematical properties of the 3D X-ray transform, two classes of algorithms will be described : the 3D filtered-backprojection methods, and the rebinning techniques for fully 3D PET which separate 3D reconstruction into a set of 2D reconstructions for a stack of parallel 2D slices.

2. Fan-beam, cone-beam and spiral X-ray CT (45 mn)
     Pierre Grangeat, LETI, CEA-Direction des Technologies Avancées, Grenoble, France

We first introduce 2D fan beam reconstruction using either direct inversion or parallel rebinning. Then we consider the extension of those approaches to one-row detector spiral CT, and to multi-row detector using either circular or spiral CT. Then, we introduce indirect cone-beam approaches via the 3D Radon domain for large area detector CT or for 3D radiology.

3. Spiral cone-beam CT : the long object problem (45mn)
    Frédéric Noo, Université Montéfiore, Liège, Belgium

We will give an overview on recent researches dedicated to spiral cone-beam tomography when the object extends axially out of the X-ray projections, the so-called long object problem. The issue is to reconstruct a given region of interest (ROI) from axially truncated projections, using a finite path covering only slightly more than the ROI. We will describe both direct and indirect inversion methods.

4. Fast algorithms (45 mn)
     Prof. Per-Erik Danielsson, Linköping University, Linköping, Sweden

Direct Fourier methods versus backprojection. Image artefacts and their remedies. Gridding and linogram techniques. Fast backprojection.

DETECTORS FOR X AND GAMMA RAY MEDICAL IMAGING
(17 October 9:00am - 12:30pm)
Organizers: Olivier Peyret (LETI, Grenoble, France); Hervé Fanet (LETI, Grenoble, France)

For the last decade, significant developments in the field of x- and gamma-ray detectors for medical imaging were led by many laboratories and manufacturers in the world. Following the present evolution towards "digital technology", the objectives of these developments are to provide detectors with direct digitised information associated with the most recent device technology. The goal is to replace the conventional screen-film system, which is widely used in radiology, as well as tube based devices (x-ray image intensifiers for fluoroscopy and photo-multiplier tubes in gamma-ray detectors). Progress occurs in combining a new high performance material (for example: fast scintillators as LSO for PET imaging, semiconductors as CdZnTe for gamma cameras) with electronics new capabilities, thanks to the integration of sophisticated read-out electronics and signal processing in ASICs (Application Specific Integrated Circuit). In the field of x-ray Imaging, efforts are oriented towards the development and the recent commercialisation of x-ray flat panel detectors based on the association of a CsI(Tl) or a selenium layer with an amorphous silicon read-out electronics panel. In the field of gamma-ray detectors, the replacement of Anger camera is dominated by the CdTe/CdZnTe technology development. Because of the great and increasing interest for PET in oncology, significant efforts are concentrated towards high performance dedicated detectors.

Outline of the course:
- Scintillators for X- and gamma-ray detectors,
  Stefaan Tavernier (Dept. Natuurkunde, Vrije Universiteit, Brussel, Belgium).
- Semi-conductors for gamma-ray detectors,
  Loïck Verger (LETI, CEA/Technologies avancées, Grenoble, France).
- X-ray detectors for digital radiography,
   Martin J.Yaffe (Dept. of Medical Biophysics and Medical Imaging, University of Toronto, Canada).

PET : STATE OF THE ART (17 October, 2:00pm - 5:30pm)
Organizers: Dale Bailey (St Thomas Hospital, UK) and
David Townsend (University of Pittsburg Medical Center, USA)

- PET systems and detectors: detectors; NaI(Tl), BGO, LSO, GSO.
Dedicated PET systems available, performance and commercial systems

- 3D PET : 3D acquisition; randoms, singles, trues : singles; transmission scanning & attenuation correction; scatter correction & quantification; normalisation

Gamma camera PET systems (GC-PET) : commercial systems available; NEMA NU2-2000 and GC-PET devices; comparison between dedicated and GC-PET devices

Multi-modality devices : PET/SPECT; PET/CT; PET/MRI

DISCRETE RECONSTRUCTION METHODS (17 October, 2:00pm - 5:30pm)
Organizer: Freek Beekman ( University Medical Hospital, Utrecht, The Netherlands/ UCLA School of Medicine)
Lecturers: Freek Beekman, Johan Nuyts (K.U Leuven, Belgium)

The introduction of new imaging devices and the increasing demand for corrective image reconstruction has brought new relevance to the topic of discrete reconstruction methods. These include methods which are suitable for modeling noise in the projection data, for incorporating prior knowledge about the object, and for model-based correction of image degrading effects (i.e. detector blurring, photon attenuation and scatter). In addition, they can be adapted rather easily to a large variety of scanner geometries. The objective of the course is to provide up-to-date practical knowledge on the emerging area of discrete image reconstruction, applied to SPECT, PET, and transmission CT.