Rapid three-dimensional MR imaging: Method for tracking a bolus of contrast agent through the brain

A gradient-echo three-dimensional magnetic resonance imaging technique (principles of echo shifting train of observations, or PRESTO) is presented for use in tracking bolus of paramagnetic contrast agent through the brain. The approach combines a segmented echo-planar type of acquisition with echo shifting, which leads to echo times that are longer than the repetition time. Unlike echo-planar imaging, the method maintains image resolution despite drastic T2* changes and frequency shifts.