3-D imaging in living samples: apparatus and techniques

A microwave bridge and magnetic field gradient generating assembly for use in reconstructing the spatial distribution of spin labels in living samples of the size of mice and other small rodents are presented. The cylindrically symmetric 16-pole magnet can generate the main field and two of the three field gradients necessary for image reconstruction. The microwave bridge has been tested at 662 MHz, making possible the observation of a 3.3*10/sup -6/ mol. physiological solution labeled with a signal-to-noise ratio of two. >