Optimizing Point Source Tracking in Awake Rat PET Imaging: A Comprehensive Study of Motion Detection and Best Correction Conditions
Source abstract
Abstract
Preclinical PET animal studies require immobilization of the animal, typically accomplished through the administration of anesthesia, which may affect the radiotracer biodistribution. The use of 18F point sources attached to the rat head is one of the most promising methods for motion compensation in awake rat PET studies. However, the presence of radioactive markers may degrade image quality. In this study, we aimed to investigate the most favorable conditions for preclinical PET studies using awake rats with attached point sources. Firstly, we investigate the optimal activity conditions for the markers and rat-injected tracer using Monte Carlo simulations to determine the parameters of maximum detectability without compromising image quality. Additionally, we scrutinize the impact of delayed window correction for random events on marker detectability and overall image quality within these studies. Secondly, we present a method designed to mitigate the influence of rapid rat movements, which resulted in a medium loss of events of around 30%, primarily observed during the initial phase of the data acquisition. We validated our study with PET acquisitions from an awake rat within the acceptable conditions of activity and motion compensation parameters. This acquisition revealed an 8% reduction in resolution compared to a sedated animal, along with a 6% decrease in signal-to-noise ratio (SNR). These outcomes affirm the viability of our method for conducting awake preclinical brain studies.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Medical Imaging Techniques and Applications · Advanced MRI Techniques and Applications · Radiopharmaceutical Chemistry and Applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Grupo de Física Nuclear, Departamento de Estructura de la Materia, Física Térmica y Electrónica & Instituto de Física de Partículas y del Cosmos, Universidad Complutense de Madrid, 28040 Madrid, Spain
Instituto de Investigación Del Hospital Clínico San Carlos (IdISSC), Ciudad Universitaria, 28040 Madrid, Spain
Paris Cardiovascular Research Center, Inserm UMR970, Université de Paris, 75015 Paris, France
Departamento de Bioingeniería, Universidad Carlos III de Madrid, 28911 Leganés, Spain
Instituto de Investigación Sanitaria del Hospital Gregorio Marañón, Unidad de Medicina y Cirugía Experimental, 28009 Madrid, Spain
Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
CIBER de Salud Mental Instituto de Salud Carlos III, 28029 Madrid, Spain
Funding
Spanish Government · Comunidad de Madrid · Spanish Ministry of Economic Affairs and Digital Transformation · European Union-Next-GenerationUE funds
References (28)
Show source-provided references
1. Alstrup, A.K., Landau, A.M., Holden, J.E., Jakobsen, S., Schacht, A.C., Audrain, H., Wegener, G., Hansen, A.K., Gjedde, A., and Doudet, D.J. (2013). Effects of anesthesia and species on the uptake or binding of radioligands in vivo in the Göttingen minipig. Biomed Res. Int., 2013.10.1155/2013/808713 ↗
2. Evaluation of anesthesia effects on [18F] FDG uptake in mouse brain and heart using small animal PET10.1016/S0969-8051(03)00124-0 ↗
3. Translation of preclinical PET imaging findings: Challenges and motion correction to overcome the confounding effect of anesthetics10.3389/fmed.2021.753977 ↗
4. Anaesthesia for positron emission tomography scanning of animal brains10.1258/la.2012.011173 ↗
5. Imaging dopamine release with positron emission tomography (PET) and 11C-raclopride in freely moving animals10.1016/j.neuroimage.2008.02.065 ↗
6. Neural responses in rat brain during acute immobilization stress: A [F-18] FDG micro PET imaging study10.1016/j.neuroimage.2008.09.032 ↗
7. MicroPET detection of enhanced 18F-FDG utilization by PKA inhibitor in awake rat brain10.1016/j.brainres.2005.01.064 ↗
8. Rat-PET study without anesthesia: Anesthetics modify the dopamine D1 receptor binding in rat brain10.1002/syn.20083 ↗
9. Conscious rat PET imaging with soft immobilization for quantitation of brain functions: Comprehensive assessment of anesthesia effects on cerebral blood flow and metabolism10.1186/s13550-021-00787-6 ↗
10. Simultaneous assessment of rodent behavior and neurochemistry using a miniature positron emission tomograph10.1038/nmeth.1582 ↗
11. Preliminary studies of a simultaneous PET/MRI scanner based on the RatCAP small animal tomograph10.1016/j.nima.2006.10.039 ↗
12. RatCAP: A small, head-mounted PET tomograph for imaging the brain of an awake RAT10.1016/j.nima.2004.03.114 ↗
13. Vaska, P., Woody, C., Schlyer, D., Pratte, J.F., Junnarkar, S., Southekal, S., Stoll, S., Schulz, D., Schiffer, W., and Alexoff, D. (November, January 26). The design and performance of the 2 nd-generation RatCAP awake rat brain PET system. Proceedings of the 2007 IEEE Nuclear Science Symposium Conference Record, Honolulu, HI, USA.10.1109/NSSMIC.2007.4437040 ↗
14. Kyme, A.Z., Zhou, V., Meikle, S.R., and Fulton, R.R. (2008). Real-time 3D motion tracking for small animal brain PET. Phys. Med. Biol., 53.10.1088/0031-9155/53/10/014 ↗
15. Kyme, A.Z., Zhou, V.W., Meikle, S.R., Baldock, C., and Fulton, R.R. (2011). Optimised motion tracking for positron emission tomography studies of brain function in awake rats. PLoS ONE, 6.10.1371/journal.pone.0021727 ↗
16. The effect of isoflurane on 18F-FDG uptake in the rat brain: A fully conscious dynamic PET study using motion compensation
17. Estimation of and correction for finite motion sampling errors in small animal PET rigid motion correction10.1007/s11517-018-1899-8 ↗
18. Classification of dynamic contrast enhanced MR images of cervical cancers using texture analysis and support vector machines10.1109/TMI.2014.2321024 ↗
19. Miranda, A., Staelens, S., Stroobants, S., and Verhaeghe, J. (2017). Markerless rat head motion tracking using structured light for brain PET imaging of unrestrained awake small animals. Phys. Med. Biol., 62.10.1088/1361-6560/aa5a46 ↗
20. Fast and accurate rat head motion tracking with point sources for awake brain PET10.1109/TMI.2017.2667889 ↗
21. Awake 18F-FDG PET imaging of memantine-induced brain activation and test–retest in freely running mice10.2967/jnumed.118.218669 ↗
22. Arias-Valcayo, F., Herraiz, J.L., Galve, P., Vaquero, J., Desco, M., and Udías, J.M. (2019, January 2–6). Awake preclinical brain PET imaging based on point sources. Proceedings of the 15th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, SPIE, Philadelphia, PA, USA.10.1117/12.2534830 ↗
23. Udias, J., Gutierrez Fernandez, C., Herraiz, J., Perez-Benito, D., Galve, P., Lopez-Montes, A., Lopez-Longas, J., Arco, J., Desco, M., and Vaquero, J. (2018, January 10–17). Performance evaluation of the PET subsystem of the extended FOV SuperArgus 6R preclinical scanner. Proceedings of the IEEE Nuclear Science Symposium and Medical Imaging Conference, Sydney, Australia.
24. Statistical image reconstruction methods for randoms-precorrected PET scans10.1016/S1361-8415(98)80017-0 ↗
25. Heußer, T., Mann, P., Rank, C.M., Schäfer, M., Dimitrakopoulou-Strauss, A., Schlemmer, H.P., Hadaschik, B.A., Kopka, K., Bachert, P., and Kachelrieß, M. (2017). Investigation of the halo-artifact in 68Ga-PSMA-11-PET/MRI. PLoS ONE, 12.10.1371/journal.pone.0183329 ↗
26. Galve, P., Arias-Valcayo, F., Montes, A., Villa-Abaunza, A., Ibanez, P., Herraiz, J., and Udías, J. (2021, January 16–21). Ultra-fast Monte Carlo PET Reconstructor. Proceedings of the 16th International Meeting on Fully 3D Image Reconstruction in Radiology and Nuclear Medicine, Stony Brook, NY, USA.
27. Arias-Valcayo, F., Galve, P., Herraiz, J.L., Desco, M., Vaquero, J.J., and Udías, J.M. (2023). Reconstruction of multi-animal PET acquisitions with anisotropically variant PSF. Biomed. Phys. Eng. Express, 9.10.1088/2057-1976/acf936 ↗
28. Miranda, A., Kroll, T., Schweda, V., Staelens, S., and Verhaeghe, J. (2023). Correction of motion tracking errors for PET head rigid motion correction. Phys. Med. Biol., 68.10.1088/1361-6560/acec2c ↗