Microstructure assessment of the thalamus in Wilson's disease using diffusion tensor imaging

Aim: To assess diffusion changes of the thalamus in Wilson's disease using diffusion tensor imaging (DTI).

Materials and methods: Fifteen patients with Wilson's disease and an abnormal signal in the thalamus (designated as group 1) and 18 patients with Wilson's disease with a normal-appearing thalamus (designated as group 2) at conventional magnetic resonance imaging (MRI) were recruited. Fifteen age-matched and sex-matched healthy volunteers were also enrolled as the control group (designated as group 3). The fractional anisotropy (FA), primary eigenvalue (λ1), second eigenvalue (λ2), and third eigenvalue (λ3) of the thalamus were measured and the differences were compared.

Results: The FA values of the thalamus were different in the three groups (group 1: 0.36 ± 0.02; group 2: 0.38 ± 0.02; group 3: 0.43 ± 0.02; F = 54.51, p < 0.001). A statistically significant difference was observed between group 1 and group 2 (p = 0.003), group 1 and group 3 (p = 0.001), and group 2 and group 3 (p < 0.001). The λ1, λ2, and λ3 values of the thalamus were different in the three groups (1.11 ± 0.06 mm(2)/s, 1.11 ± 0.06 mm(2)/s, and 1.10 ± 0.04 mm(2)/s of λ1 in group 1, group 2, and group 3, respectively; 0.82 ± 0.08 mm(2)/s, 0.78 ± 0.05 mm(2)/s, and 0.72 ± 0.02 mm(2)/s of λ2 in group 1, group 2, and group 3, respectively; 0.52 ± 0.05 mm(2)/s, 0.49 ± 0.06 mm(2)/s, and 0.42 ± 0.06 mm(2)/s of λ3 in group 1, group 2, and group 3, respectively; F = 1.65, p = 0.203 of λ1; F = 10.55, p < 0.001 of λ2; F = 4.21, p = 0.021 of λ3; respectively). A statistically significant difference in the λ2 value was observed between group 1 and group 3 (p < 0.001) and group 2 and group 3 (p = 0.005). A statistically significant difference in the λ3 value was also observed between group 1 and group 3 (p = 0.007). No significant difference in the λ1 value was noted between each of the two groups.

Conclusions: Damage of the thalamus in Wilson's disease patients can be detected using DTI. DTI may provide information regarding thalamus damage in patients with Wilson's disease before abnormal signals on conventional MRI.