Performance evaluation of small-animal multipinhole μSPECT scanners for mouse imaging
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We compared the performance of three commercial small-animal μSPECT scanners equipped with multipinhole general purpose (GP) and multipinhole high-resolution (HR) collimators designed for imaging mice.
Spatial resolution, image uniformity, point source sensitivity and contrast recovery were determined for the U-SPECT-II (MILabs), the NanoSPECT-NSO (BioScan) and the X-SPECT (GE) scanners. The pinhole diameters of the HR collimator were 0.35 mm, 0.6 mm and 0.5 mm for these three systems respectively. A pinhole diameter of 1 mm was used for the GP collimator. To cover a broad field of imaging applications three isotopes were used with various photon energies: 99mTc (140 keV), 111In (171 and 245 keV) and 125I (27 keV). Spatial resolution and reconstructed image uniformity were evaluated in both HR and a GP mode with hot rod phantoms, line sources and a uniform phantom. Point source sensitivity and contrast recovery measures were additionally obtained in the GP mode with a novel contrast recovery phantom developed in-house containing hot and cold submillimetre capillaries on a warm background.
In hot rod phantom images, capillaries as small as 0.4 mm with the U-SPECT-II, 0.75 mm with the X-SPECT and 0.6 mm with the NanoSPECT-NSO could be resolved with the HR collimators for 99mTc. The NanoSPECT-NSO achieved this resolution in a smaller field-of-view (FOV) and line source measurements showed that this device had a lower axial than transaxial resolution. For all systems, the degradation in image resolution was only minor when acquiring the more challenging isotopes 111In and 125I. The point source sensitivity with 99mTc and GP collimators was 3,984 cps/MBq for the U-SPECT-II, 620 cps/MBq for the X-SPECT and 751 cps/MBq for the NanoSPECT-NSO. The effects of volume sensitivity over a larger object were evaluated by measuring the contrast recovery phantom in a realistic FOV and acquisition time. For 1.5-mm rods at a noise level of 8 %, the contrast recovery coefficient (CRC) was 42 %, 37 % and 34 % for the U-SPECT-II, X-SPECT and NanoSPECT-NSO, respectively. At maximal noise levels of 10 %, a CRCcold of 70 %, 52 % and 42 % were obtained for the U-SPECT-II, X-SPECT and NanoSPECT-NSO, respectively. When acquiring 99mTc with the GP collimators, the integral/differential uniformity values were 30 %/14 % for the U-SPECT-II, 50 %/30 % for the X-SPECT and 38 %/25 % for the NanoSPECT-NSO. When using the HR collimators, these uniformity values remained similar for U-SPECT-II and X-SPECT, but not for the NanoSPECT-NSO for which the uniformity deteriorated with larger volumes.
We compared three μSPECT systems by acquiring and analysing mouse-sized phantoms including a contrast recovery phantom built in-house offering the ability to measure the hot contrast on a warm background in the submillimetre resolution range. We believe our evaluation addressed the differences in imaging potential for each system to realistically image tracer distributions in mouse-sized objects.
KeywordsSmall-animal imaging SPECT Pinhole Multipinhole
This work was supported by the University of Antwerp, the Research Foundation – Flanders (FWO), the Belgian Science Policy Office (BELSPO), iMinds and Ghent University. The authors would like to thank Peter Laverman of Radboud University Nijmegen, Ruud Ramakers of the University Medical Center Utrecht, Ciara Finucane and Jerome Burnet of Queen Mary, University of London, and Alessandro Passeri of the University of Florence for their cooperation and technical assistance with, respectively, the U-SPECT-II, the NanoSPECT-NSO and the X-SPECT measurements.
Conflicts of interest
- 3.Bailey DL, Karp JS, Surti S. Physics and instrumentation in PET, in positron emission tomography: basic science and clinical practice. Philadelphia: Springer; 2003. p. 41–67.Google Scholar
- 6.McElroy DP, MacDonald LR, Beekman FJ, Yuchuan Wang, Patt BE, Iwanczyk JS, et al. Evaluation of A-SPECT: a desktop pinhole SPECT system for small animal imaging. Nuclear Science Symposium Conference Record, 2001 IEEE, vol. 3, pp. 1835–1839, 2001. doi: 10.1109/NSSMIC.2001.1008699.
- 7.Weber DA, Ivanovic M, Franceschi D, Strand SE, Erlandsson K, Franceschi M, et al. Pinhole SPECT: an approach to in vivo high resolution SPECT imaging in small laboratory animals. J Nucl Med. 1994;35:342–8.Google Scholar
- 10.Wilson DW, Barrett HH, Furenlid LR. A new design for a SPECT small-animal imager. Nuclear Science Symposium Conference Record, 2001 IEEE, vol. 3, pp. 1826–1829, 2001.doi: 10.1109/NSSMIC.2001.1008697.
- 11.Meikle SR, Kench P, Weisenberger AG, Wojcik R, Smith MF, Majewski S, et al. A prototype coded aperture detector for small animal SPECT. Nuclear Science Symposium Conference Record, 2001 IEEE, vol. 3, pp. 1580–1584, 2001.doi: 10.1109/NSSMIC.2001.1008641.
- 17.Miller BW, Furenlid LR, Moore SK, Barber HB, Nagarkar VV, Barrett HH. System Integration of FastSPECT III, a Dedicated SPECT Rodent-Brain Imager Based on BazookaSPECT Detector Technology. IEEE Nucl Sci Symp Conf Rec (1997) 2009, Oct. 24 2009-Nov. 1 2009;4004–4008.Google Scholar
- 34.Cherry SR, Sorensen J, Phelps ME. Physics in nuclear medicine. Philadelphia: Saunders; 2012.Google Scholar
- 39.Van Steenkiste C, Staelens S, Deleye S, De Vos F, Vandenberghe S, Geerts A, et al. Measurement of porto-systemic shunting in mice by novel three-dimensional micro-single photon emission computed tomography imaging enabling longitudinal follow-up. Liver Int. 2010;30:1211–20.PubMedCrossRefGoogle Scholar
- 43.Vangestel C, Van de Wiele C, Mees G, Mertens K, Staelens S, Reutelingsperger C, et al. Single-photon emission computed tomographic imaging of the early time course of therapy-induced cell death using technetium 99m tricarbonyl His-annexin A5 in a colorectal cancer xenograft model. Mol Imaging. 2012;11:135–47.PubMedGoogle Scholar
- 44.Vangestel C, Van de Wiele C, Van Damme N, Staelens S, Pauwels P, Reutelingsperger CP, et al. (99)mTc-(CO)(3) His-annexin A5 micro-SPECT demonstrates increased cell death by irinotecan during the vascular normalization window caused by bevacizumab. J Nucl Med. 2011;52:1786–94.PubMedCrossRefGoogle Scholar
- 50.Lin K, Hsiao I-T, Wietholt C, Chung Y, Chen C, Yen T. Performance evaluation of an animal SPECT using modified NEMA standards. J Nucl Med. 2008;49 Suppl 1:402P.Google Scholar
- 51.Schramm NU, Lackas C, Hoppin JW, Forrer F, de Jong M. The NanoSPECT/CT: a high-sensitivity small-animal SPECT/CT with submillimeter spatial resolution. Eur J Nucl Med Mol Imaging. 2006;47: Supl 1:233P.Google Scholar
- 52.Schramm NU, Lackas C, Gershman B, Norenberg JP, de Jong M. Improving resolution, sensitivity and applications for the NanoSPECT/CT: a high-performance SPECT/CT imager for small-animal research. Eur J Nucl Med Mol Imaging. 2007;34:S226–7.Google Scholar
- 53.Gershman B, Hoppin J, Schramm N, Lackas C, Norenberg J. Evaluation of the quantification capabilities of a NanoSPECT/CT as a function of angular sampling, counting statistics, reconstruction parameters and the dynamic range of measured activity. J Nucl Med. 2007;48:433P.Google Scholar
- 55.McLarty K, Cornelissen B, Cai Z, Scollard DA, Costantini DL, Done SJ, et al. Micro-SPECT/CT with 111In-DTPA-pertuzumab sensitively detects trastuzumab-mediated HER2 downregulation and tumor response in athymic mice bearing MDA-MB-361 human breast cancer xenografts. J Nucl Med. 2009;50:1340–8.PubMedCrossRefGoogle Scholar
- 56.National Electrical Manufacturers Association. Standards Publication NU 1–2007. Rosslyn: National Electrical Manufacturers Association; 2007.Google Scholar
- 57.National Electrical Manufacturers Association. Performance measurements of positron emission tomographs. Rosslyn: National Electrical Manufacturers Association; 2001.Google Scholar
- 61.Visser EP, Harteveld AA, Meeuwis AP, Disselhorst JA, Beekman FJ, Oyen WJ, et al. Image quality phantom and parameters for high spatial resolution small-animal SPECT. J Nucl Med. 2011;52:1646–53.Google Scholar
- 67.Magota K, Kubo N, Kuge Y, Nishijima KI, Zhao S, Tamaki N. Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging. Eur J Nucl Med Mol Imaging. 2011;38:742–52.Google Scholar
- 68.Boisson F, Zahra D, Parmar A, Meikle S, Rellbac A. Mouse imaging capabilities of the Inveon SPECT system using single and multi-pinhole collimators dedicated to mouse studies. World Molecular Imaging Congress. 2012. Abstract P139.Google Scholar
- 69.Meikle SR, Kench P, Kassiou M, Banati RB. Small animal SPECT and its place in the matrix of molecular imaging technologies. Phys Med Biol. 2005;50:R45–61.Google Scholar