ASSESSMENT OF PATIENT DOSE REDUCTION BY BISMUTH SHIELDING IN CT USING MEASUREMENTS, GEANT4 AND MCNPX SIMULATIONS

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Mendes, M (Author) Other; Costa, F (Author) Other; Figueira, C (Author) Other; Madeira, P (Author) Other; Teles, P (Author) Other; Vaz, P (Author) Other

Journal

Title: Radiation Protection Dosimetry

Vol. 165

Pages: 175-181

ISSN: 0144-8420

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 14 Citations

Other information

Authenticus ID: P-00G-FKB

DOI: 10.1093/rpd/ncv059

Abstract (EN): This work reports on the use of two different Monte Carlo codes (GEANT4 and MCNPX) for assessing the dose reduction using bismuth shields in computer tomography (CT) procedures in order to protect radiosensitive organs such as eye lens, thyroid and breast. Measurements were performed using head and body PMMA phantoms and an ionisation chamber placed in five different positions of the phantom. Simulations were performed to estimate Computed Tomography Dose Index values using GEANT4 and MCNPX. The relative differences between measurements and simulations were <10 %. The dose reduction arising from the use of bismuth shielding ranges from 2 to 45 %, depending on the position of the bismuth shield. The percentage of dose reduction was more significant for the area covered by the bismuth shielding (36% for eye lens, 39 % for thyroid and 45 % for breast shields).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7