title: New devices for imaging in nuclear medicine.
abstract: Pinhole gamma camera imaging offers the ability to obtain high resolution images from single gamma ray emitting radiotracers playing a reasonable tradeoff between very small field of view (FoV) and sensitivity. On the other hand the total spatial resolution of a pinhole imaging device is predominantly affected by the detector intrinsic spatial resolution for reduced magnification factors. To design very compact pinhole SPET scanners with very high intrinsic spatial resolution, authors investigated a miniature gamma camera based on the newly developed Hamamatsu H8500 flat panel photomultiplier. The PSPMT was coupled to the following scintillation arrays: CsI(Tl) array with 0.2-mm, 1-mm, 1.4-mm pixel size and NaI (Tl) with 1-mm pixel size. The imaging performances were evaluated by 57Co spot and flood irradiations. NaI(Tl) array shows a better pixel identification for 1 mm pixel size, proving to be a good candidate to make a large area photodetector based on multi PSPMTs closely packed. Although CsI(Tl) array had the smallest pixel size, the low light output limited the best intrinsic spatial resolution to about 0.5 mm.
authors.affiliation: Department of Experimental Medicine and Pathology, University "La Sapienza," Rome, Italy. roberto.pani@uniroma1.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Pani
authors.forename: Rosanna
authors.initials: R
authors.lastname: Pellegrini
authors.forename: Maria Nerina
authors.initials: MN
authors.lastname: Cinti
authors.forename: Carlo
authors.initials: C
authors.lastname: Trotta
authors.forename: Paolo
authors.initials: P
authors.lastname: Bennati
authors.forename: Margherita
authors.initials: M
authors.lastname: Betti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Vincentis
authors.forename: Francesco
authors.initials: F
authors.lastname: Cusanno
authors.forename: Franco
authors.initials: F
authors.lastname: Garibaldi
authors.forename: Stefano
authors.initials: S
authors.lastname: Ridolfi
authors.forename: Stan
authors.initials: S
authors.lastname: Majewsky
authors.forename: Benjamin M W
authors.initials: BM
authors.lastname: Tsui
mesh_terms: D015902:Gamma Cameras; D005720:Gamma Rays; D009683:Nuclear Medicine / Q000295:instrumentation* / Q000379:methods*; D011856:Radiographic Image Enhancement; D015899:Tomography, Emission-Computed, Single-Photon