Multiparametric Quantitative Brain MRI in Neurological and Hepatic Forms of Wilson's Disease

Background In Wilson's disease (WD), demyelination, rarefaction, gliosis, and iron accumulation in the deep gray matter cause opposing effects on T 2 ‐weighted MR signal. However, the degree and interplay of these changes in chronically treated WD patients has not been quantitatively studied. Purpose To compare differences in brain multiparametric mapping between controls and chronically treated WD patients with neurological (neuro‐WD) and hepatic (hep‐WD) forms to infer the nature of residual WD neuropathology. Study Type Cross‐sectional. Population/Subjects Thirty‐eight WD patients (28 neuro‐WD, 10 hep‐WD); 26 healthy controls. Field Strength/Sequence 3.0T: susceptibility, T 2 *, T 2 , T 1 relaxometry; 1.5T: T 2 , T 1 relaxometry. Assessment The following 3D regions of interest (ROIs) were manually segmented: globus pallidus, putamen, caudate nucleus, and thalamus. Mean bulk magnetic susceptibility, T 2 *, T 2 , and T 1 relaxation times were calculated for each ROI. Statistical Tests The effect of group (neuro‐WD, hep‐WD, controls) and age was assessed using a generalized least squares model with different variance for each ROI and quantitative parameter. A general linear hypothesis test with Tukey adjustment was used for post‐hoc between‐group analysis; P < 0.05 was considered significant. Results Susceptibility values were higher in all ROIs in neuro‐WD compared to controls and hep‐WD ( P < 0.001). In basal ganglia, lower T 2 and T 2 * were found in neuro‐WD compared to controls ( P < 0.01) and hep‐WD ( P < 0.05) at 3.0T. Much smaller intergroup differences for T 2 in basal ganglia were observed at 1.5T compared to 3.0T. In the thalamus, increased susceptibility in neuro‐WD was accompanied by increased T 1 at both field strengths ( P < 0.001 to both groups), and an increased T 2 at 1.5T only ( P < 0.001 to both groups). Data Conclusion We observed significant residual brain MRI abnormalities in neuro‐WD but not in hep‐WD patients on chronic anticopper treatment. Patterns of changes were suggestive of iron accumulation in the basal ganglia and demyelination in the thalamus; 3.0T was more sensitive for detection of the former and 1.5T of the latter abnormality. Level of Evidence: 2 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:1829–1835.