Description of facility
The imaging unit consists of an imaging suite of both functional and anatomical imaging for the purpose of in vivo imaging in mice. The systems available in the imaging unit are small animal versions of similar devices available in the clinic for the purpose of translational research.
Bruker Biospec 7T MRI
Magnetic resonance imaging (MRI) is a powerful medical imaging modality that can provide anatomical and physiological information using strong magnetic fields and radiofrequency waves to manipulate the nuclear spin. Anatomical images can be formed through T1 and T2 weighted imaging, and contrast agents can be used to distinguish tumors from surrounding tissue. Physiological information can also be determined with techniques such as diffusion, perfusion, and angiography. Moreover, relative metabolite concentrations can be determined through spectroscopy. For these reasons, MRI is one of the most useful cancer imaging modalities.
T1-weighted MRI of a brain tumor after injection of a gadolinium contrast agent.
Single positron emission tomography (SPECT) is another type of nuclear imaging, which generates images via the detection of gamma-emitting radiotracers. The most commonly used SPECT isotope is 99mTc, which is often labelled with methylene diphosphonate in order to detect bone metastases. There are numerous SPECT radiotracers available, which can be used for a variety of techniques, such as bone scans, myocardial perfusion, and radiotherapy.
99mTc-MAG3 SPECT/CT of a mouse showing high uptake in the liver and kidney.
Positron emission tomography (PET) is a type of nuclear imaging where functional information is ascertained via the injection of positron-emitting radiotracers. PET is often combined with computed tomography (CT), which provides a 3D anatomical correlation using x-rays. Together, PET/CT can be used to accurately and precisely locate tumors through the detection of high uptake of the injected radiotracer. The most commonly used tracer is 18F-fluorodeoxyglucose (FDG), which is taken up by highly energetic tissues, such as tumors. Other commonly used tracers include 68Ga-DOTATATE, which aids in the detection of neuroendocrine tumors by binding to somatostatin receptors, and 18F-choline, which can detect quickly proliferating cells such as tumors that take up choline for the generation of phospholipids in the cell membrane. Due to the abundance of radiotracers available, PET/CT is a primary detection method for several types of tumors and metastases.
18F-FDG PET (in color) fused with CT data showing high uptake in the heart, bladder, and brown fat.
High resolution CT of a mouse.
Bruker ICON 1T MRI
Low field Magnetic resonance imaging (MRI) is useful for basic anatomical correlation of nuclear medicine. CT is already incorporated into the PET and SPECT systems, but has limited soft tissue contrast. A multimodal bed is available to provide registered PET/CT and MRI data.
18F-FDG PET (in color) fused with 1T MRI data
PerkinElmer IVIS Spectrum
Optical imaging is a highly useful imaging modality for cancer research, which is used for bioluminescence and fluorescence imaging. Bioluminescence imaging is often performed via the incorporation of the luciferase protein into tumor cells that are subsequently injected into a laboratory mouse. By injecting D-luciferin, light is produced and tumor growth can be tracked by the intensity of the light. Fluorescence imaging can be likewise useful in tumor monitoring via the incorporation of fluorescent markers in the tumor cells or the injection of fluorescent dyes.
IVIS bioluminescence imaging of a mammary tumor