Introduction: The purpose of this study was to assess the clinical feasibility of diffusion tensor imaging (DTI) for the evaluation of peripheral nerves in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).
Methods: Using a 3-T magnetic resonance imaging scanner, we obtained DTI scans of the tibial nerves of 10 CIDP patients and 10 sex- and age-matched healthy volunteers. We prepared fractional anisotropy (FA) maps, measured the FA values of tibial nerves, and compared these values in the two study groups. In nine patients, we also performed tibial nerve conduction studies and analyzed the correlation between the FA values and parameters of the nerve conduction study.
Results: The tibial nerve FA values in CIDP patients (median 0.401, range 0.312-0.510) were significantly lower than those in healthy volunteers (median 0.530, range 0.469-0.647) (Mann-Whitney test, p < 0.01). They were significantly correlated with the amplitude of action potential (Spearman correlation coefficient, p = 0.04, r = 0.86) but not with nerve conduction velocity (p = 0.79, r = 0.11).
Conclusion: Our preliminary data suggest that the noninvasive DTI assessment of peripheral nerves may provide useful information in patients with CIDP.