Clinical evaluation of a motion compensated double echo sequence in MRI of the brain.

This study is a clinical evaluation on 5 volunteers and 20 patients of an improved sequence using rephasing gradients for motion compensation, applied to MR imaging of the brain at 1.5 T. The sequence is a double spin echo sequence with a normal first echo at TE = 15 ms and a second echo at TE = 90 ms with first and second order motion compensation in the readout gradient direction; the band width of the second echo is halved for improved S/N. Results demonstrate a dramatic improvement in image quality. Vascular and CSF flow are rephased, ghosting is reduced and signal voids no longer exist. Most remarkable is the substantial suppression of artifacts from voluntary movements such as from swallowing or rotation of the eyes. ECG triggering does not further improve image quality and is thus no longer needed.