NEW TECHNIQUE FOR OBTAINING NMR LINEWIDTH IMAGES OF LUNG AND OTHER INHOMOGENEOUSLY BROADENED SYSTEMS

A new imaging technique is presented which displays the regional variation of the local NMR linewidth (rather than the spin density). The linewidth in a localized region is obtained from measuring the height of the spin echo as a function of asymmetry time (τa) in an asymmetric spin-echo imaging sequence. This technique has been used to obtain linewidth images from a phantom consisting of closely packed spherical glass beads (100 μm diameter) in water, normal excised unperfused rat lungs, and a thorax phantom consisting of sponges surrounding by water. The NMR linewidths determined using the new imaging technique are comparable to those obtained from nonimaging measurements. © 1993 Academic Press, Inc.