A modified quadrupole gradient set for use in high resolution MRI tagging.

A special purpose gradient set with a Cos(2 theta) current distribution has been constructed for high resolution MR imaging of small samples in a clinical Signa 1.5 T scanner using the existing gradient amplifiers. The X, Y, and Z gradient coils can attain gradient field strengths of 11.3, 4.7, and 15.2 G/cm at 100 amps current, respectively, with a slew rate of 20 G/cm/ms and usable ramp time of 150 microseconds. Field distortions are less than 2% over the central 8 cm of the bore, suitable for high resolution tagging of isolated canine hearts.