Structural and neurochemical evaluation of the brain and pons in patients with Wilson's disease.
ABSTRACT The aim of this study was to examine the structural-neurochemical abnormalities of the frontal white matter (FWM), deep gray matter nuclei, and pons in patients with Wilson's disease (WD) using proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI).
Nine patients with WD and 14 age-matched controls were examined with MRS. N-Acetylaspartate (NAA), choline (Cho), and creatine (Cr) peaks were calculated. DWI scans from six WD patients and six controls were also obtained. The relative metabolite ratios and apparent diffusion coefficient (ADC) values of the WD patients were compared to those of the control subjects by using statistical measures.
Measurements in the thalamus and pons showed significantly lower NAA/Cho and NAA/Cr ratios in the WD group than in the control group (P < 0.05). Thalamic and pontine Cho/Cr ratios in the patient group were significantly higher than those of the control group (P < 0.05). No statistically significant relation was found between the patient and control groups as a result of the MRS examinations of FWM and all ADC measurements (P > 0.05).
MRS is a noninvasive, valuable modality for detecting structural-neurochemical changes of the brain stem and deep gray matter in patients with WD. The contribution of DWI in these patients is limited.
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ABSTRACT: To assess diffusion changes of the thalamus in Wilson's disease using diffusion tensor imaging (DTI). 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. 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. 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.Clinical Radiology 12/2013; 69(3). DOI:10.1016/j.crad.2013.10.016 · 1.66 Impact Factor
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ABSTRACT: To evaluate neurochemical and structural changes in the patients with newly diagnosed obstructive sleep apnea syndrome (OSAS) by MR spectroscopy (MRS), T2 relaxometry, and diffusion weighted imaging (DWI). Following the acquisition of routine cranial MR, MRS, T2 relaxometry, and DWI images; spectroscopic metabolite ratios and DWI-T2 relaxometry findings of the thalami, hippocampi, frontal white matter (FWM) and frontal cortex of 24 OSAS patients and 9 controls were statistically compared. The relationship between two groups was evaluated with Mann-Whitney test. Spectroscopic measurements in the frontal cortex and frontal white matter of the OSAS patients revealed significantly lower NAA/Cr ratios than those of the control group (P=0.004 and P=0.006, respectively). The measurements in the frontal white matter of the OSAS patients exhibited significantly lower NAA/Cho ratios compared with those of the control group (P=0.005). Thalamic Cho/Cr ratios of the patient group were significantly higher than those of the control group (P=0.002). In terms of the ADC-T2 relaxometry values, there was no significant relationship between the patient and the control groups (P>0.05). MRS is a useful and non-invasive modality in showing neurochemical changes in various regions of the brain but our data does not show any change on diffusion weighting or T2 quantification in the OSAS group. DWI and T2 relaxometry appear to be not effective techniques to evaluate the brain structural changes of the patients with newly diagnosed OSAS.European journal of radiology 02/2011; 81(3):491-5. DOI:10.1016/j.ejrad.2010.12.092 · 2.16 Impact Factor