T2 Relaxation of peripheral nerve measured in vivo

It is demonstrated that multi-exponential transverse (T2) relaxation components can be estimated from multi-echo images of peripheral nerve. Three T2-relaxation components with T2 values ± standard deviations (populations ± standard deviations) of 19 ± 7 ms (26 ± 9%), 63 ± 31 ms (29 ± 11%) and 241 ± 24 ms (45 ± 7%) have been identified in vivo in the sciatic nerve of the amphibian Xenopus laevis. The longer-lived component, not identified previously in vivo, provides a significant contrast-to-noise ratio (CNR) between nerve and muscle in the latter-echo images. It is shown that the CNR can be further improved by the averaging of selected images from the multi-echo set.