Magnetic Resonance Imaging (MRI)

It really depends on the type of scan (e.g. anatomical, diffusion, magnetization transfer). A typical scanning session to acquire an anatomical MRI scan for brain atrophy analysis is ~1 hour. This session includes animal positioning, scout scans, shimming, and a high-resolution anatomical scan.

The spatial resolution depends on the type of scan. For anatomical scans that we use for brain volume and cortical thickness analysis to measure brain atrophy, we typically acquire 3D whole brain scans with an isotropic resolution of 140 µm.

We perform our studies using a 7 Tesla small animal MRI scanner (Bruker BioSpec 70/30 USR). We have all of the RF coils, gradient inserts, and physiological monitoring systems to perform multi-modality MRI studies in mice and rats.

Our team has developed a proprietary software platform called NIGHTWING™. NIGHTWING™ is modeled on our human brain image processing platform. It is unique in that it allows for fully-automated measures, such as neuroanatomical volumes and regional cortical thickness, from the entire mouse brain. The fully-automated nature of NIGHTWING™ eliminates unwanted intra- and inter-rater variability and allows us to rapidly process a large number of scans from our rodent model studies.

While MRI is more expensive than some of our other tests, it can be very cost-effective for several reasons:

• Allows assessment of drug efficacy as part of the in-life phase of the study
• Allows longitudinal measures from the same animal
• Can provide go-/no-go decision making for post-mortem studies (e.g. immunohistochemistry)
• Provides the best measures of brain atrophy