Comparative Study of Imaging Characteristics of I-125 Imaging Using the Siemens Inveon Scanner and Siemens Symbia TruePoint


Objective: Although Iodine-125 (125I) has been widely used for in vitro studies because of its relatively long half-life (60.1 days), 125I imaging is limited because of its low energy (27 - 35 keV), even in an animal-dedicated system. In this study, imaging characteristics of 125I were assessed using a small animal-dedicated imaging system and clinical scanner. Methods: Using the Siemens Inveon and Siemens Symbia TruePoint systems, imaging characteristics such as resolution, sensitivity, and image quality were compared. Mouse high resolution (MHR-0.5), mouse general purpose (MGP-1.0), and mouse high sensitivity (MHS-2.0) collimators were used for the Inveon scanner, and low energy high-resolution (LEHR) and low energy all-purpose (LEAP) collimators were used for the Symbia TruePoint. For animal imaging, 16.8 MBq of 125I was administered to BALB/c mice intravenously, and the planar image and single-photon emission computed tomography (SPECT) were obtained using both scanners. Results: The resolution of 125I for the Inveon scanner was 3.98 mm full width at half maximum (FWHM) at a 30-mm distance with the MHR-0.5 collimator, and the value of Symbia scanner was 8.72 mm FWHM at a 30-mm distance with the LEHR collimator. The sensitivity of 125I for the Inveon scanner was 21.87 cps/MBq, and the value for the clinical scanner was 30.55 cps/MBq. The planar images of mice were successfully obtained at the level of evaluating specific binding in both scanners. Conclusion: 125I small animal imaging can be achieved with a clinical scanner. This result may enhance the utilization of 125I small animal imaging using a clinical scanner.

Share and Cite:

Kim, Y. , Lim, I. , Yu, A. , Kim, B. , Choi, C. , Lim, S. and Kim, J. (2015) Comparative Study of Imaging Characteristics of I-125 Imaging Using the Siemens Inveon Scanner and Siemens Symbia TruePoint. Journal of Biomedical Science and Engineering, 8, 674-683. doi: 10.4236/jbise.2015.810064.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Beekman, F.J., et al. (2002) Towards in Vivo Nuclear Microscopy: Iodine-125 Imaging in Mice Using Micro-Pinholes. European Journal of Nuclear Medicine and Molecular Imaging, 29, 933-938.
[2] Dilmanian, F.A., et al. (1990) A High Resolution SPECT System Based on a Microchannel-Plate Imagier. IEEE Transactions on Nuclear Science, 37, 687-695.
[3] Kim, E.M., et al. (2009) Characterization, Biodistribution and Small-Animal SPECT of I-125-Labeled c-Met Binding Peptide in Mice Bearing c-Met Receptor Tyrosine Kinase-Positive Tumor Xenografts. Nuclear Medicine and Biology, 36, 371-378.
[4] Franc, B.L., et al. (2008) Small-Animal SPECT and SPECT/CT: Important Tools for Preclinical Investigation. Journal of Nuclear Medicine, 49, 1651-1663.
[5] Meikle, S.R., et al. (2005) Small Animal SPECT and Its Place in the Matrix of Molecular Imaging Technologies. Physics in Medicine and Biology, 50, R45-R61.
[6] Weber, D.A., et al. (1994) Pinhole SPECT: An Approach to in Vivo High Resolution SPECT Imaging in Small Laboratory Animals. Journal of Nuclear Medicine, 35, 342-348.
[7] Herschman, H.R. (2003) Molecular Imaging: Looking at Problems, Seeing Solutions. Science, 302, 605-608.
[8] Hwang, A.B., et al. (2008) Assessment of the Sources of Error Affecting the Quantitative Accuracy of SPECT Imaging in Small Animals. Physics in Medicine and Biology, 53, 2233-2252.
[9] Scherfler, C. and Decristoforo, C. (2006) Small Animal Imaging Using a Conventional Gamma Camera Exemplified in Studies on the Striatal Dopaminergic System. Nuclear Medicine Review Central East Europe, 9, 6-11.
[10] Aide, N., et al. (2010) High Throughput Static and Dynamic Small Animal Imaging Using Clinical PET/CT: Potential Preclinical Applications. European Journal of Nuclear Medicine and Molecular Imaging, 37, 991-1001.
[11] Khalil, M.M., Tremoleda, J.L., Bayomy, T.B. and Gsell, W. (2011) Molecular SPECT Imaging: An Overview. International Journal of Molecular Imaging, 2011, Article ID: 796025.
[12] Umeda, I.O., Tani, K., Tsuda, K., Kobayashi, M., Ogata, M., Kimura, S., et al. (2012) High Resolution SPECT Imaging for Visualization of Intratumoral Heterogeneity Using a SPECT/CT Scanner Dedicated for Small Animal Imaging. Annals of Nuclear Medicine, 26, 67-76.
[13] Rowland, D.J. and Cherry, S.R. (2008) Small-Animal Preclinical Nuclear Medicine Instrumentation and Methodology. Seminars in Nuclear Medicine, 38, 209-222.
[14] Harteveld, A.A., Meeuwis, A.P.W., Disselhorst, J.A., Slump, C.H., Oyen, W.J.G., Boerman, O.C. and Visser, E.P. (2011) Using the NEMA NU 4 PET Image Quality Phantom in Multipinhole Small-Animal SPECT. Journal of Nuclear Medicine, 52, 1646-1653.
[15] Medical, S. (Ed.) (2005) SymbiaTM TruePoint SPECT/CT System Specifications.
[16] Medical, S. (Ed.) (2006) InveonTM System Specifications Data.
[17] Macey, D.J., DeNardo, G.L., De-Nardo, S.J. and Hines, H.H. (1986) Comparison of Low- and Medium-Energy Collimators for SPECT Imaging with Io-dine-123-Labeled Antibodies. Journal of Nuclear Medicine, 27, 1467-1474.
[18] Magota, K., Kubo, N., Kuge, Y., Nishijima, K.-I., Zhao, S.J. and Tamaki, N. (2011) Performance Characterization of the Inveon Preclinical Small-Animal PET/SPECT/CT System for Multimodality Imaging. European Journal of Nuclear Medicine and Molecular Imaging, 38, 742-752.
[19] Kojima, A., Matsumoto, M., Takahashi, M., Hirota, Y. and Yoshida, H. (1989) Effect of Spatial Resolution on SPECT Quantification Values. Journal of Nuclear Medicine, 30, 508-514.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.