Accuracy of Low-Count SPECT Imaging in Mice
Author Information
Author(s): Ciara M. Finucane, Iain Murray, Jane K. Sosabowski, Julie M. Foster, Stephen J. Mather
Primary Institution: Centre for Molecular Oncology and Imaging, Barts Cancer Institute, Queen Mary University of London
Hypothesis
We aimed to determine the accuracy of the NanoSPECT/CT preclinical imaging system for achieving absolute quantification data with both high and low activity concentrations.
Conclusion
The quantitative information provided by the NanoSPECT camera is accurate and allows replacement of dissection studies for assessment of radiotracer biodistribution in mouse models.
Supporting Evidence
- The use of an appropriate calibration phantom and disabling of a background subtraction feature meant that absolute errors were within 12% of the true activity.
- A comparison of in vivo imaging and biodistribution studies in mice showed a correlation of 0.99 for activities over the 200 kBq to 5 MBq range.
- The system was reproducible with a coefficient of variation below 1% for activities higher than 0.5 MBq.
Takeaway
This study shows that a special camera can accurately measure tiny amounts of radioactivity in mice, which helps scientists understand how drugs work without needing to do surgery.
Methodology
The study involved imaging with the NanoSPECT/CT camera, using various activity concentrations in phantoms and tumor-bearing mice, and comparing the results to true activity levels.
Potential Biases
Potential systematic errors due to differences in attenuation between calibration syringes and phantom tubes.
Limitations
The study only addresses quantitation of activity in mice using either Tc-99m or In-111 and does not explore larger animals or lower energy isotopes.
Participant Demographics
26 female immunodeficient beige SCID mice were used in the study.
Statistical Information
P-Value
0.99
Statistical Significance
p<0.001
Digital Object Identifier (DOI)
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