Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Megavoltage CT on a tomotherapy system
Autore:
Ruchala, KJ; Olivera, GH; Schloesser, EA; Mackie, TR;
Indirizzi:
Univ Wisconsin, Sch Med, Dept Med Phys, Med Sci Ctr 1530, Madison, WI 53706 USA Univ Wisconsin Madison WI USA 53706 d Sci Ctr 1530, Madison, WI 53706 USA Univ Wisconsin, Sch Med, Dept Human Oncol, Med Sci Ctr 1530, Madison, WI 53706 USA Univ Wisconsin Madison WI USA 53706 d Sci Ctr 1530, Madison, WI 53706 USA
Titolo Testata:
PHYSICS IN MEDICINE AND BIOLOGY
fascicolo: 10, volume: 44, anno: 1999,
pagine: 2597 - 2621
SICI:
0031-9155(199910)44:10<2597:MCOATS>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
POSITRON EMISSION TOMOGRAPHY; EXPECTATION MAXIMIZATION RECONSTRUCTION; MAXIMUM-LIKELIHOOD RECONSTRUCTION; COMPUTED-TOMOGRAPHY; EM ALGORITHM; ITERATIVE RECONSTRUCTION; CONVOLUTION/SUPERPOSITION METHOD; TRANSMISSION TOMOGRAPHY; CONFORMAL RADIOTHERAPY; TREATMENT VERIFICATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
79
Recensione:
Indirizzi per estratti:
Indirizzo: Ruchala, KJ Univ Wisconsin, Sch Med, Dept Med Phys, Med Sci Ctr 1530, 1300Univ Ave, Madison, WI 53706 USA Univ Wisconsin 1300 Univ Ave Madison WI USA 53706 WI 53706 USA
Citazione:
K.J. Ruchala et al., "Megavoltage CT on a tomotherapy system", PHYS MED BI, 44(10), 1999, pp. 2597-2621

Abstract

A megavoltage computed tomography (MVCT) system was developed on the University of Wisconsin tomotherapy benchtop. This system can operate either axially or helically, and collect transmission data without any bounds on delivered dose. Scan times as low as 12 s per slice are possible, and scans were run with linac output rates of 100 MU min(-1), although the system can betuned to deliver arbitrarily low dose rates. Images were reconstructed with clinically reasonable doses ranging from 8 to 12 cGy. These images delineate contrasts below 2% and resolutions of 3.0 mm. Thus, the MVCT image quality of this system should be sufficient for verifying the patient's position and anatomy prior to radiotherapy. Additionally, synthetic data were used to test the potential for improved MVCT contrast using maximum-likelihood (ML) reconstruction. Specifically, the maximum-likelihood expectation-maximization (ML-EM) algorithm and a transmission ML algorithm were compared with filtered backprojection (FBP). It was found that for expected clinical MVCT doses enough imaging photons are used such that little benefit is conferred by the improved noise model of ML algorithms. For significantly lower doses, some quantitative improvement is achieved through ML reconstruction. Nonetheless, the image quality at those lower doses is not satisfactory for radiotherapy verification.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/04/20 alle ore 11:49:06