Speaker
Dr
Evaristo Cisbani
(Istituto Superiore di Sanita' - Istituto Nazionale di Fisica Nucleare)
Description
Recently there has been a growing interest in molecular imaging techniques by
radionuclides. In the imaging techniques panorama incluidng MRI, x-ray CT, optical,
etc., they have a specific role due to their unique features. For example, they are
extremely sensitive (picomolar) that is needed for imaging biological processes “in
vivo”. A wide range of human diseases can be studied in animal models. Also, it is
possible to provide early detection of small tumors with high specificity.
Nevertheless, the techniques are technologically challenging because of the
concurrent requirements in both high spatial resolution and high sensitivity. The
limitation of the sensitivity due to the collimation is well known and affects the
performance of detector systems, especially if only radiopharmaceuticals with
limited uptake are available. The “electronic” collimation technique used in
Positron Emisson Tomography (PET) has intrinsic limitations in terms of spatial
resolution. Moreover, it is often not well suited for some applications, for
example involving protracted longitudinal measurements, or for the reasons of
applicable biochemistry. An electronic collimation method for single gamma
emissions using Compton camera techniques is rather complicated, expensive and not
yet fully developed. Multi-pinhole and coded aperture collimation are promising
solutions to improve sensitivity. This is the case at least for “small volumes”
imaging involving small animals. In this paper we will present simulations
performed for optimizing the performances of dedicated detectors with multi-pinhole
and coded aperture collimation taking into account factors that affect spatial
resolution, dimension of scintillator pixels, and pixel identification, number of
pixels per unit area, signal-to-noise (SNR) and contrast. Phantom as well as
preliminary small animal imaging measurements have been performed to evaluate the
performance of the molecular imaging techniques for specific small animal imaging
studies.
Author
Dr
Francesco Cusanno
(Istituto Nazionale di Fisica Nucleare)
Co-authors
Dr
Benjamin M. W. Tsui
(Johns Hopkins University)
Dr
Evaristo Cisbani
(Istituto Superiore di Sanita' - Istituto Nazionale di Fisica Nucleare)
Mr
Fabio Santavenere
(Istituto Superiore di Sanita')
Mr
Fausto Giuliani
(Istituto Superiore di Sanita')
Dr
Franco Garibaldi
(Istituto Superiore di Sanita' - Istituto Nazionale di Fisica Nucleare)
Dr
Maria Lucia Magliozzi
(University "La Sapienza")
Mr
Massimo Gricia
(Istituto Superiore di Sanita')
Mr
Maurizio Lucentini
(Istituto Superiore di Sanita')
Mr
Piero Veneroni
(Istituto Superiore di Sanita')
Mr
Rolando Fratoni
(Istituto Superiore di Sanita')
Dr
Sergio Torrioli
(C.I.S.B.)
Dr
Stan Majewski
(Jefferson Lab)
Mr
Stefano Colilli
(Istituto Superiore di Sanita')
Dr
Vladimir Popov
(Jefferson Lab)