SIMFp – Preclinical Multimodal and Functional Imaging System
The SIMFp (Preclinical Multimodal and Functional Imaging System) provides an advanced platform for in vivo imaging in small animals, primarily mice and rats. The system integrates multiple imaging modalities that allow simultaneous analysis of anatomical structure, metabolic activity, molecular processes, and cellular dynamics, offering a comprehensive view of experimental models.
The infrastructure is particularly notable for its integration of optical and nuclear imaging technologies, enabling studies ranging from gene expression or cell migration to the precise anatomical localization of lesions or pathophysiological processes. In biomedical research, multimodal preclinical imaging has become an essential technology for understanding disease mechanisms and evaluating new therapeutic strategies.
System Description
The infrastructure combines two main platforms:
• LAGO optical imaging system (Spectral Instruments Imaging) for bioluminescence and fluorescence.
• MOLECUBES modular system integrating PET, SPECT, and CT for high-resolution molecular and structural imaging.
This combination makes SIMFp a unique infrastructure, as the integration of the LAGO platform with the MOLECUBES modular system is currently unprecedented in Spain, enabling the combination of high-sensitivity optical imaging with nuclear and tomographic modalities.
The PET, SPECT, and CT modules of the MOLECUBES system can operate independently, although PET and SPECT acquisitions are generally co-registered with CT.
Both the LAGO area and the micro PET/SPECT/CT suite are equipped with inhalation anesthesia, thermal control, and multimodal positioning systems, enabling complex studies while maintaining the animal’s physiological conditions during imaging. Furthermore, MOLECUBES modules allow ECG and respiratory monitoring.
System Features
Optical Imaging (Bioluminescence and Fluorescence)
The LAGO system enables bioluminescence (BLI) and fluorescence (FLI) studies with extremely high sensitivity thanks to a high-performance cooled CCD camera (-90 ºC) and a multispectral LED illumination array (20 LEDs).
Main features include:
• Detection of very weak light signals, ideal for gene expression or cell-tracking studies.
• Large field of view (up to 25 × 25 cm) enabling simultaneous imaging of multiple animals.
• Capacity for imaging up to 10 mice simultaneously.
• Spectral filter systems for multichannel fluorescence analysis.
• Absolute calibration, eliminating the need to adjust settings between experiments.
PET Imaging (β-CUBE)
PET imaging enables the study of metabolic and molecular processes using positron-emitting radiotracers such as ¹⁸F, ⁶⁸Ga, or ⁸⁹Zr.
Main features of the β-CUBE module:
• Spatial resolution below 850 µm
• High sensitivity (>12%)
• Dynamic acquisitions for kinetic studies
• Whole-body imaging for mice and rats
• Possibility of simultaneous multi-animal imaging.
SPECT Imaging (γ-CUBE)
The SPECT module enables nuclear imaging using gamma-emitting isotopes such as ⁹⁹ᵐTc or ¹⁷⁷Lu.
Characteristics of the equipment:
• Resolution below 500 µm
• Dedicated mouse and rat collimators
• Whole-body imaging capability
• Multi-isotope study support
• Physiological monitoring during acquisition.
Computed Tomography (X-CUBE CT)
The CT system provides high-resolution anatomical images with voxel sizes down to 50 µm, enabling precise visualization of bone and soft tissues.
Main capabilities:
• High-resolution anatomical imaging
• Whole-body studies
• Respiratory- or cardiac-gated acquisitions
• Advanced iterative reconstruction
• Excellent tissue contrast.
CT also provides attenuation correction and anatomical co-registration for PET and SPECT.
Tecnhology applications
The SIMFp platform enables advanced studies in multiple areas of biomedical research, combining functional, molecular, and anatomical information.
Cancer Research
One of the most widespread applications of multimodal imaging is the study of tumor progression and response to therapy.
• ¹⁸F-FDG PET for assessing tumor glucose metabolism.
• Bioluminescence imaging for monitoring luciferase-expressing tumor cells.
• CT imaging for anatomical localization of tumors and metastases.
This combination enables longitudinal tumor monitoring in the same animal and evaluation of experimental anticancer therapies.
Drug Development and Evaluation
Preclinical imaging is essential in pharmacological research and drug development. Examples include:
• PET for studying antibody or nanoparticle biodistribution.
• SPECT for assessing uptake of receptor-targeted radiotracers.
• Optical imaging for monitoring drug-induced cellular responses.
• Nanoparticle development combining fluorescence and PET tracers for guided radiodiagnostics, such as sentinel lymph node detection.
These techniques allow non-invasive assessment of pharmacokinetics, pharmacodynamics, and therapeutic efficacy.
Neuroscience
In neuroscience, preclinical PET imaging allows the study of brain processes such as:
• Neuronal metabolism (¹⁸F-FDG).
• Neuroinflammation (TSPO-targeted tracers).
• Synaptic activity (receptor/transporter ligands).
• Neurodegeneration (visualization of β-amyloid and tau in Alzheimer’s models).
This enables non-invasive monitoring of disease progression and therapeutic impact.
Immunology and Infectious Disease
Optical imaging techniques enable real-time monitoring of immunological processes and infections with high sensitivity.
• Tracking fluorescently labelled immune cells.
• Bioluminescence monitoring of bacterial or viral infections.
• Analysis of inflammatory processes and immune-cell dynamics.
Funding
This equipment was fully funded through European support (2021 Scientific-Technical Equipment Acquisition Call, Next Generation EU Recovery, Transformation and Resilience Plan / Project EQC2021-007451-P), with a total amount of €1,039,346.
Location
The SIMFp is located within the In Vivo Experimentation Unit of the Bellvitge Medicine Campus.