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Titolo:
Physical characteristics of the ECAT EXACT3D positron tomograph
Autore:
Spinks, TJ; Jones, T; Bloomfield, PM; Bailey, DL; Miller, M; Hogg, D; Jones, WF; Vaigneur, K; Reed, J; Young, J; Newport, D; Moyers, C; Casey, ME; Nutt, R;
Indirizzi:
Univ London Imperial Coll Sci Technol & Med, Hammersmith Hosp, Sch Med, MRC Cyclotron Unit, London W12 0NN, England Univ London Imperial Coll Sci Technol & Med London England W12 0NN gland CTI PET Syst, Knoxville, TN USA CTI PET Syst Knoxville TN USACTI PET Syst, Knoxville, TN USA
Titolo Testata:
PHYSICS IN MEDICINE AND BIOLOGY
fascicolo: 9, volume: 45, anno: 2000,
pagine: 2601 - 2618
SICI:
0031-9155(200009)45:9<2601:PCOTEE>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
VOLUME-IMAGING PET; FULLY 3D PET; RETRACTABLE SEPTA; SCATTER CORRECTION; LUTETIUM OXYORTHOSILICATE; PERFORMANCE EVALUATION; ATTENUATION CORRECTION; PENN-PET; SCANNER; RECONSTRUCTION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
52
Recensione:
Indirizzi per estratti:
Indirizzo: Spinks, TJ Univ London Imperial Coll Sci Technol & Med, Hammersmith Hosp, Sch Med, MRC Cyclotron Unit, Ducane Rd, London W12 0NN, England Univ LondonImperial Coll Sci Technol & Med Ducane Rd London England W12 0NN
Citazione:
T.J. Spinks et al., "Physical characteristics of the ECAT EXACT3D positron tomograph", PHYS MED BI, 45(9), 2000, pp. 2601-2618

Abstract

The 'EXACT3D' positron tomograph, which is now in routine clinical research use, was developed with the aim of achieving unprecedented sensitivity, high spatial and temporal resolution and simplicity of design using proven detector technology. It consists of six rings of standard detector blocks (CTI/Siemens EXACT HR+) with 4.39 mm x 4.05 mm x 30 mm elements, giving an axial field of view (FOV) of 23.4 cm. This extended FOV and the absence of interplane septa and retractable transmission rod sources has allowed greatlysimplified gantry and detector cassette design. Operation in exclusive 3D mode requires an alternative to the conventional coincidence method for transmission scanning, and a single photon approach using a hydraulically driven Cs-137 point source has been implemented. The tomograph has no other moving parts. A single time frame of data without any compression is very large (>300 Mbyte) and two approaches are employed to overcome this difficulty:(a) adjacent sinograms can be summed automatically into different combinations and (b) listmode (event-by-event) acquisition has been instituted, which is both storage efficient (particularly for acquisition of sparse data sets) and maximizes temporal resolution. The high-speed I/O and computing hardware can maintain a sustained acquisition rate of about 4 million coincidence events per second. A disadvantage of the large axial FOV in 3D is the increased sensitivity to activity outside the coincidence FOV. However, this can be minimized by additional side shielding. The mean spatial resolution is 4.8+/-0.2 mm FWHM (transaxial, 1 cm off-axis) and 5.6 +/- 0.5 mm (axial, on-axis). Its absolute efficiency is 5.8% for a line source in air (justspanning the axial FOV) and 10% for a central point source (with thresholds of 350-650 keV). For a uniform 20 cm diameter cylinder, the efficiency is69 kcps kBq(-1) ml(-1) (after subtraction of a scatter fraction of 42%). Sensitivity relative to the EXACT HR+ (with four rings of blocks) is 2.5 (3D) and 12 (2D) times respectively. The rate of random events in blood flow studies in the brain and body, using O-15-labelled water, can be controlled by limiting the administered dose and inserting additional side shielding.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/11/20 alle ore 16:19:19