MRI-Changes of Skeletal Muscle after Denervation and LIB Elec- trical Stimulation

In the present animal study, MRI (Magnetic Resonance Imaging) evaluation of fast rabbit muscles revealed a distinct increase of signal intensity and T2 relaxation time following chronic denervation. These changes were less pronounced after treatment with LIB (long impulse bidirectional) electrical stimulation, a type of stimulation which is extremely effec-tive in avoiding muscle atrophy. One month after denervation, there was a slight increase of signal intensity as well in the stimulated as in the untreated animals. After two months, however, there was a further increase only in the non-stimulated muscles, which was statis-tically significant. T2 relaxation time showed a slight increase after one month of therapy, while there was a significant increase after one and two months without therapy. After 3-6 months of electrical stimulation, there was no increase of T2 at all.- The results indicate 1), that MRI can be used when monitoring stimulation effects on denervated muscle, and 2), that, for this purpose, T2 relaxation time is more useful than signal intensity