MRI Texture Analysis Reveals Deep Gray Nuclei Damage in Amyotrophic Lateral Sclerosis.

BACKGROUND AND PURPOSE: Amyotrophic Lateral Sclerosis (ALS) is characterized by extensive corticospinal damage, but extrapyramidal involvement is suggested in pathological studies. Texture analysis (TA) is an image processing technique that evaluates the distribution of gray levels between pixels in a given region of interest (ROI). It provides quantitative data and has been employed in several neurodegenerative disorders. Here, we used TA to investigate possible deep gray nuclei (DGN) abnormalities in a cohort of ALS patients. METHODS: Thirty-two ALS patients and 32 healthy controls underwent MRI in a 3T scanner. The T1 volumetric sequence was used for DGN segmentation and extraction of 11 texture parameters using the MaZda software. Statistical analyses were performed using the Mann-Whitney non-parametric test, with a significance level set at α = 0.025 (FDR-corrected) for TA. RESULTS: Patients had significantly higher values for the parameter correlation (CO) in both thalami and in the right caudate nucleus compared to healthy controls. Also, the parameter Inverse Difference Moment or Homogeneity (IDM) presented significantly smaller values in the ALS group in both thalami. CONCLUSIONS: TA of T1 weighted images revealed DGN alterations in patients with ALS, namely in the thalami and caudate nuclei.

MRI-texture analysis of corpus callosum, thalamus, putamen, and caudate in Machado-Joseph disease.

BACKGROUND/PURPOSE: Texture analysis (TA) is a branch of image processing, which attempts to convey "texture" information from digital images, such as magnetic resonance images (MRI). Machado-Joseph disease (MJD) affects mainly cerebellum and brainstem, but recent studies have shown that other cerebral structures may also be affected. OBJECTIVE: To investigate subtle structural abnormalities in corpus callosum (CC), thalami, putamen, and caudate nuclei of patients with MJD using TA. METHODS: Eighteen healthy volunteers and 18 patients with MJD were studied (mean age at disease onset = 34.7 years; disease duration = 9.6 years; mean expanded CAG in the MJD1 gene = 73). A TA approach based on the gray-level cooccurrence matrix was applied to T1-MRI. Regions of interest were manually segmented for each subject, and texture parameters were computed for each of the aforementioned anatomical structures. RESULTS: TA parameters showed differences between the 2 groups for the caudate nuclei, thalami, and putamen. No differences were found for the CC. CONCLUSIONS: TA was capable of detecting tissue alterations in MRI of patients with MJD. These alterations were in areas already shown to be affected by histopathological studies. In addition, we confirmed the thalamic involvement in patients with MJD, which had only been demonstrated in volumetric studies.