Radiology, Vol 155, 159-162, Copyright © 1985 by Radiological Society of North America
Multi-section multi-echo pulse magnetic resonance techniques: optimization in a clinical setting
JB Kneeland, RJ Knowles and PT Cahill
The user-selectable magnetic resonance imaging parameters involved in a
multi-section multi-echo pulse sequence are described and their
interrelationships explained. These parameters include repetition time
(TR), echo delay time (TE), the number of sections (S), the number of
echoes (E'), the time from the center of the last echo to the end of data
acquisition (15 msec on the authors' system), and the time for T1 recovery.
A simple mathematical relationship among these quantities, permitting easy
calculation of the remaining parameters once a sufficient number have been
specified, is given. In addition, a nomogram that permits rapid visual
estimation of these parameters is presented. The effects of these choices
and others is explained with respect to imaging time, region covered, and
image contrast. Finally, the inherent trade-offs are illustrated in a
clinical example involving the pelvis.
