A practical prescription for magnetic resonance microscopy in a horizontal bore magnet

Magnetic resonance microscopy (MRM) produces high spatial resolution proton images of biological tissues, plants, and porous media, revealing microstructural details and contrast unattainable by other means. A major challenge in MRM is the low signal-to-noise ratio at high spatial resolutions, as smaller voxels produce smaller MR signals. This necessitates the use of highly sensitive microcoils, high-performance gradient systems, and high magnetic fields. Here, we present a step-by-step prescription for fabricating a cost-effective, flexible microimaging probe system compatible with horizontal bore high-field MRI systems. We demonstrate performance at 15.2 T by acquiring high-resolution (15 μm isotropic voxels) images of ex vivo mouse spinal cord (gray matter SNR 38; 46 h scan) and hippocampus (SNR 67; 45 h scan), clearly resolving microstructural features. Shorter imaging times are possible using compressed sampling. The flexible probe design supports solenoid diameters ranging from < 1 mm up to 10 mm in diameter, offering flexibility for imaging a variety of biological samples at high resolution.