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 (pri nciples of echo shifting train of observations, or PRESTO) is presented for use in tracking bolus of paramagnetic contrast agent through the brain. Th e approach combines a segmented echo-planar type of acquisition with echo s hifting, 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.