Browsing by Author "Price, R"

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    Peformance evaluation of preclinical PET scanners with the NEMA NU-4 image quality phantom using a collection of radioisotopes
    (John Wiley & Sons, Inc., 2013-04-13) Nezich, R; Reilhac, A; Zahra, D; Price, R
    Background: The radioisotopes 18F, 11C, 124I, 68Ga, 89Zr and 64Cu have found numerous applications in small animal PET imaging, and this entire subset of isotopes will soon be available to Australian preclinical researchers. The suitability of an isotope for a given imaging application is determined largely by its radioactive half-life. However, other characteristic physical properties of the isotope such as the branching fraction and positron energy can severely impact image quality and the ability to accurately quantify uptake of the radio-labelled molecule. Furthermore, the specific acquisition parameters and reconstruction algorithms employed to generate the image can significantly affect the image quality and quantification accuracy. The NEMA NU-4 2008 standards describe a method to evaluate the performance of small animal PET scanners. The information gathered through the NEMA Image Quality phantom scanning experiment is valuable for optimising the scanner usage, because it allows for the best selection of acquisition/reconstruction protocols and provides knowledge of the resolution limits of the system. Method: NEMA NU-4 image quality phantom performance testing was performed on the Siemens Inveon with 18F, 124I and 64Cu, using default acquisition parameters and each of the available reconstruction algorithms. Further testing will be performed using 11C, 68Ga and 89Zr. The Bioscan NanoPET scanner will be tested with all of the mentioned isotopes. Results: The figure shows NU-4 phantom images obtained for 18F, 64Cu and 124I; using the Inveon preclinical scanner and FBP2D reconstruction. The relatively poor image quality obtained with 124I is mainly caused by single gamma-photon contamination. Due to a higher positron range, recovery coefficients obtained with 124I are well below the values measured with 18F. Conclusion: NEMA NU-4 performance testing provides valuable information about the image quality achievable for a given PET scanner and radioisotope. © 2003 John Wiley & Sons, Inc.
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    Synthesis of hexa aza cages, SarAr-NCS and AmBaSar and a study of their metal complexation, conjugation to nanomaterials and proteins for application in radioimaging and therapy
    (Royal Society of Chemistry, 2013-07-01) Mume, E; Asad, A; Di Bartolo, NM; Kong, L; Smith, C; Sargeson, AM; Price, R
    A novel hexa aza cage, N1-(4-isothiocyanatobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1,8-diamine (SarAr-NCS) was synthesized in good yield and characterized by 1H NMR and electrospray mass spectrometry. A new method for the synthesis of the related N1-(4-carboxybenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1,8-diamine (AmBaSar) using the p-carboxybenzaldehyde is reported. The complexation of Cu2+, Co2+ and Zn2+ by the two ligands over a range of pHs was found to be similar to the parent derivative SarAr. SarAr-NCS was conjugated to both silica particles (≈90 nm diam.) and the model B72.3 murine antibody. The SarAr-NCSN-silica particles were radiolabeled with Cu2+ doped 64Cu and the number of ligands conjugated was calculated to be an average of 7020 ligands per particle. Conjugation of SarAr-NCS to the B72.3 antibody was optimized over a range of conditions. The SarAr-NCSN-B72.3 conjugate was stored in buffer and as a lyophilized powder at 4 °C over 38 days. Its radiolabeling efficiency, stability and immunoreactivity were maintained. The development of a high yielding synthesis of SarAr-NCS should provide an entry point for a wide range of Cu and Zn radiometal PET imaging agents and potentially radiotherapeutic agents with 67Cu. © 2013, The Royal Society of Chemistry.