BACKGROUND: Nuclear medicine scans may be accompanied by CT acquisitions to provide localization of radioisotope uptake through image fusion and for use in attenuation correction. The effective doses to patients resulting from radioisotope administrations and from diagnostic CT scans are well documented. However, the development of gamma cameras with low dose CT attachments introduces the requirement for calculation of effective doses arising from non-standard CT acquisitions. In this study, the CT function of the GE Infinia Hawkeye was investigated and effective doses were calculated using various methods in order to assess the suitability of standard CT dose calculation methods. METHODS: Dose measurements were performed using Perspex head and body phantoms and the results were used in three calculation methods: (1) the ImPACT CT dosimetry calculator used Monte Carlo dose data to calculate effective doses; (2) organ fractions exposed by each scan were estimated and applied to dose measurements and ICRP tissue weighting factors; (3) standard conversion factors were used with measured and displayed dose indices to provide the simplest method of calculation. RESULTS: The maximum variation in effective dose using each calculation method was within 10% of the mean. Average effective doses from CT scans acquired using the Hawkeye were 0.9 mSv for a chest scan, 1.5 mSv for an abdomen-pelvis scan, and 0.1 mSv for a head scan, all significantly lower than doses resulting from diagnostic CT scans. CONCLUSION: These doses may be used for justification of radiation exposures in accordance with IR(ME)R 2000, in association with the accompanying radioisotope dose.
BACKGROUND: Nuclear medicine scans may be accompanied by CT acquisitions to provide localization of radioisotope uptake through image fusion and for use in attenuation correction. The effective doses to patients resulting from radioisotope administrations and from diagnostic CT scans are well documented. However, the development of gamma cameras with low dose CT attachments introduces the requirement for calculation of effective doses arising from non-standard CT acquisitions. In this study, the CT function of the GE Infinia Hawkeye was investigated and effective doses were calculated using various methods in order to assess the suitability of standard CT dose calculation methods. METHODS: Dose measurements were performed using Perspex head and body phantoms and the results were used in three calculation methods: (1) the ImPACT CT dosimetry calculator used Monte Carlo dose data to calculate effective doses; (2) organ fractions exposed by each scan were estimated and applied to dose measurements and ICRP tissue weighting factors; (3) standard conversion factors were used with measured and displayed dose indices to provide the simplest method of calculation. RESULTS: The maximum variation in effective dose using each calculation method was within 10% of the mean. Average effective doses from CT scans acquired using the Hawkeye were 0.9 mSv for a chest scan, 1.5 mSv for an abdomen-pelvis scan, and 0.1 mSv for a head scan, all significantly lower than doses resulting from diagnostic CT scans. CONCLUSION: These doses may be used for justification of radiation exposures in accordance with IR(ME)R 2000, in association with the accompanying radioisotope dose.
Authors: E Gordon Depuey; John J Mahmarian; Todd D Miller; Andrew J Einstein; Christopher L Hansen; Thomas A Holly; Edward J Miller; Donna M Polk; L Samuel Wann Journal: J Nucl Cardiol Date: 2012-04 Impact factor: 5.952
Authors: Giuliano Mariani; Laura Bruselli; Torsten Kuwert; Edmund E Kim; Albert Flotats; Ora Israel; Maurizio Dondi; Naoyuki Watanabe Journal: Eur J Nucl Med Mol Imaging Date: 2010-02-25 Impact factor: 9.236
Authors: Tarik Z Belhocine; Michel Prefontaine; Dominique Lanvin; Monique Bertrand; Irina Rachinsky; Helen Ettler; Pamela Zabel; Larry W Stitt; Akira Sugimoto; Jean-Luc Urbain Journal: Am J Nucl Med Mol Imaging Date: 2013-03-08
Authors: D Cecchin; I Schiorlin; A Della Puppa; G Lombardi; P Zucchetta; V Bodanza; M P Gardiman; G Rolma; A C Frigo; F Bui Journal: Biomed Res Int Date: 2014-03-27 Impact factor: 3.411