Cardiomics

Cardiomics Mouse Imaging

Capturing anatomical, functional and molecular data from a moving target

By combining unprecedented high temporal and spatial resolution on a hexamodal-imaging platform, MILabs’ VECTor4CT systems enable to visualize and study new areas of mouse cardio-vascular disease previously not possible. For the first time, one can acquire in vivo anatomical, functional and molecular images of the mouse heart with organ definition and fluidity of contraction comparable or better to what can be achieved in humans. Among the VECTor4CT unique cardiomics capabilities are:

1. Dynamic SPECT and dynamic PET myocardial innervation, viability and absolute blood flow (MBF) quantification.
2. Concurrent PET/SPECT imaging of a co-injected 99mTc perfusion tracer and e.g. 82Rb or 18F-FDG.
3. Contrast-enhanced hybrid nuclear/CT multi-gated imaging combining 4D angiography and 4D perfusion imaging.
4. Computation of global cardiac functional metrics from 4D micro-CT data sets using short, quantitative, low-radiation-dose protocols.

Featuring high-performance hexamodal imaging technologies, i.e. SPECT, PET, CT, Bioluminescence, Fluorescence and Cherenkov imaging, MILabs VECTor4CT makes it now possible to extract with just one imaging study, a wide range of functional and morphological/kinetic data to better delineate heart disease with more proven efficacy than separately used modalities.

 

MILabs’ VECTor4CT system makes anatomical, functional and molecular cardiomics evaluation possible in a completely non-invasive way.

 

Multiple Dynamic Cardiac Functions and Morphology in a Single Scan

Equipped with retrospective respiratory- and cardiac gating for high-end PET, SPECT and CT, VECTor4CT further enhances the utility of hybrid PET/CT and SPECT/CT for comprehensive cardiac function imaging. Unlike rotational gantry SPECT scanners, the U-SPECT technology as implemented on the VECTor4CT platform enables for the first time high temporal sampling of high-resolution SPECT and PET tracer kinetics making monitoring dynamic cardiac functional changes including absolute cardiac blood flow feasible.

Virtually any combination of SPECT and PET tracers can be used allowing 4D dynamic PET/SPECT quantitative multi-isotope cardiac acquisitions. This allows for acquisition of complementary information – like innervation, viability, metabolism and perfusion – or translational evaluation using similar tracers labeled with either a SPECT or PET isotope simultaneously. With VECTor’s concurrent PET/SPECT capabilities, common cardiac SPECT tracers such as 99mTc-teboroxime, 99mTc-tetrofosmin, 99mTc-sestamibi, 123I-mIBG or 201Tl can be used in conjunction with PET perfusion or metabolic tracers such as 82Rb and FDG by co-injection of tracers in the same animal.


 

Myocardial Perfusion and Coronary Angiography in a Single Scan

While myocardial perfusion imaging can be performed with either the SPECT or PET modalities, the excellent performance of the integrated high-end CT system enables to complement perfusion information with coronary angiography, thus improving the specificity and overall diagnostic accuracy of detecting the hemodynamic significance of coronary artery stenosis.

For perfusion studies, both PET and SPECT tracers are available. In small animal imaging, SPECT tracers such as 99mTc-tetrofosmin are better suited as they provide the resolution necessary for delineating small regions within the mouse heart. Translation to the clinic with a switch to PET tracers such as 82Rb or 18F-flurpiridaz is streamlined by using the VECTor4CT simultaneous PET and SPECT acquisition capability of co-injected tracers enabling a direct comparison of tracers.

Despite the challenges associated with these studies such as the fast motion of the heart (up to 600 beats per minute) and the microscopic dimensions of the coronary vessels (diameter of less than 100 μm) plus in addition the low blood flow within these vessels, the autonomous CT gantry design enables fast and low-dose imaging at resolutions down to 10 μm. While several in vivo techniques using contrast agents exist for imaging vasculature, few are able to visualize the vascular network as a whole while extending to a resolution that includes the smaller vessels. One method, which enables imaging the smaller vessels, is to fill the excised heart with microfil MV120, a radiopaque silicone rubber, in the cardiac arteries. This ultra-high resolution ex vivo option on the VECTor4CT platform can be used to complement MILabs’ Exirad-3D autoradiography method.


 

Myocardial Viability

While the concurrent PET/SPECT functionality of VECTor4CT enables to image myocardial viability at sub-mm resolution with FDG-PET, the system can simultaneously and quantitatively assess perfusion with any of the established SPECT tracers. Single-step comparison of the SPECT perfusion images with 18F-FDG PET images will allow for therapy response stratification including differentiation of scar tissue from normal myocardium and progression to scar tissue in response to therapy.


 

Cardiac Cell Therapy

Cardiac stem cell therapy holds promise for the treatment of ischemic heart disease. the complementary imaging techniques available on the VECTor4CT including fluorescence imaging (FI), bioluminescence imaging (BLI), PET, SPECT and CT have all been validated for tracking stem cells.

With VECTor4CT, researchers can exploit the synergy between the various modalities on a single platform, and select a given modality best suited for the intended application. For example, when selecting an appropriate cell marker, the researcher can decide to use direct labeling with a fluorescent probe, or PET tracers such as FDG or 89Zr-oxine, or SPECT tracers such as 99mTc-HMPAO or 111In-oxine. Alternatively, if the researcher is interested in longitudinal studies over long periods and/or measuring cell viability, it is possible to trace cells using reporter genes e.g. a fluorescent protein (GFP) or bioluminescence (Luciferase) for optical imaging, the HSV-tk reporter (together with 18F-FHBG) for PET, or the NIS reporter (together with 99mTc-pertechnetate or 123I) for SPECT imaging.

While the choices are manifold, and the optimal strategy may vary depending on the research question at hand, the ability of VECTor4CT to acquire multimodal acquisitions under identical physical and physiological conditions makes concurrent use of complementary tracers and co-registration of datasets easy. Moreover, with concurrent PET/SPECT translation to PET for the clinical imaging (e.g. from 111In-oxine to 89Zr-oxine) can be done in a single step.


 

Autonomic Myocardial Function and Molecular Applications

Since the autonomic nervous system is the primary extrinsic control of heart rate and contractility, noninvasive imaging of myocardial innervation using SPECT or PET is a valuable additional methodology in cardiac imaging. The use of the FDA-approved 123I-mIBG for sympathetic nerve imaging is well established while ligands for autonomic PET imaging have mostly been labeled with short-lived, cyclotron-supported tracers (e.g. 11C-mHED). Since VECTor4CT can detect a wide-variety of PET tracers including 11C, 18F, 64Cu, 68Ga, etc. and a one-step direct comparison of new autonomic PET tracers with the established 123I-mIBG SPECT tracer is enabled with concurrent PET/SPECT imaging, the platform is considered an invaluable tool for cardiovascular applications of the autonomic nervous system.

Meet Us At

Scroll to Top