Nuclear Science Symposium
Chairman for Short Courses:
Short description of the courses
SOLID STATE DETECTORS IN HIGH ENERGY PHYSICS (15 October,
properties of detectors:
silicon detectors in large experiments:
PARTICLE IDENTIFICATION AT HIGH ENERGIES (15 October, 9:00am-
motivations and requirements for PID at high energies,
DETECTORS FOR X-AND GAMMA-RAY ASTROPHYSICS (15 October, 9:00am -
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)
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)
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)
3. Spiral cone-beam CT :
the long object problem (45mn)
4. Fast algorithms (45
DETECTORS FOR X AND GAMMA RAY MEDICAL IMAGING
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.
of the course:
PET : STATE OF THE ART (17 October, 2:00pm - 5:30pm)
- PET systems and
detectors: detectors; NaI(Tl), BGO, LSO, GSO.
- 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)
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.