Mouse Imaging with Whole-Body MRI Scanners

Magnetic Resonance Imaging has been used in clinical applications for several decades. It offers a physician excellent anatomic detail and tissue characterization. Within the past decade, advances in MRI allowed us to image with a sub-millimetre in-plane resolution. Achieving such reduction in voxel volume require novel technological developments in every aspect of the MRI acquisition process: RF and gradient hardware and pulse sequence software. At the same time there is growing interest in Magnetic Resonance Microscopy studies of small animal models of human disease. In general MR microscopy studies can be done exclusively on a specialized imager equipped with a small bore gradient coil. We have developed new techniques for inserting a custom designed and built, high-strength gradient coil into an existing clinical MR imager. Such inserts can produce strong gradient fields that lead to maximum spatial resolution and excellent signal sensitivity. We describe the interfacing and calibration methods that we developed for our custom inserts in both 1.5T and 3T General Electric MR scanners. We show that all tests have met the specifications of the clinical gradient coil. The implemetation of our method allow for switching between clinical and research modes without having to purchase and maintain another MR system.