Purpose: To define various cranial MR appearances in Wilson's disease (WD).
Material and methods: MR examinations of 30 patients (9-44 years old) with WD were retrospectively reviewed. Six patients were asymptomatic siblings. Three other patients had isolated hepatic involvement, one with no symptoms. The remaining 21 patients had neurological involvement, 7 of whom had the mixed form of the disease. Nine patients had hepatic dysfunction, the 3 with isolated hepatic involvement and 6 of the 7 with the mixed form.
Results: All symptomatic patients (n = 23) had abnormal MR examinations, Atrophy was present in the majority of them. The most frequently involved sites were putamen (18/21) and pons (18/21) in patients with neurological abnormality. The putaminal lesions showed a consistent pattern of symmetric, bilateral, concentric-laminar T2 hyperintensity. Putaminal lesions were lacking in only 3 patients with neurological involvement, all of whom were relatively old and had had the disease for a longer duration. Most of the patients with hepatic dysfunction (8/9) had increased T1 signal intensity in the basal ganglia, particularly in the globus pallidus. Pontine involvement always included the dorsal aspect of the pons, however, in some cases the central portion of pons was also affected but ventrolateral longitudinal fibers were spared. Midbrain (16/21), thalamic (10/21) and caudate nucleus lesions (9/21) were also encountered. In a few patients cortical and subcortical white matter lesions were present with a predilection to the frontal lobe, particularly the precentral region. In one patient, a hemorrhagic focus was identified within the white matter lesion.
Conclusion: On T2-weighted images, WD is suggested by: atrophy; putaminal lesions with a pattern of symmetric, bilateral, concentric-laminar T2 hyperintensity; and the involvement of the pars compacta of the substantia nigra, periaqueductal gray matter, the pontine tegmentum and the thalamus. The hepatic component of WD may cause increased T1 signal intensity in basal ganglia. In the adult age group, the basal ganglia lesions may be different from those in the pediatric group; the putaminal lesions may not be present; the globus pallidus and substantia nigra may show increased hypointensity on T2-weighted images. Cortical and subcortical lesions may also be present with a predilection to the frontal lobe.