Table 2.
Main Neuroimaging Modalities Available for Spinocerebellar Ataxias Evaluation
| Modality | Information Afforded | Clinical Utility | Current Availability |
|---|---|---|---|
| CT | Identification of gross brain abnormalities. | Useful to characterize the main partners of atrophy, but not specifically. | Widely available. |
| MRI | Identification of abnormalities with accuracy to gray matter, white matter, and cerebrospinal fluid. | Useful to characterize the main partners of atrophy and signal changes, specifically; more sensitive to subtle alterations. | Available in developed geographic regions. Limited availability in underdeveloped areas. |
| Three-dimensional (3D) true volumetric methods and voxel-based morphometry allow automated segmentation and comparison between groups, in both cross-sectional and longitudinal studies. | Limited to specialized research centers. | ||
| MRS | Identification and interpretation of altered metabolites concentration in specific areas. | Assess physiological function of the observable metabolites and their concentration changes. Specific areas should be assessed. | Limited to specialized centers. |
| fMRI | Analyses of perfusion-induced changes in image contrast, during performance of a task. | Color maps superimposed on morphological images allows visualizing both positive correlation (greater activation during task) and negative correlation (reduced activation during task). | Limited to specialized research centers. |
| FDG-PET | Regional brain glucose metabolism | Downstream marker of neuronal injury and neurodegeneration. Important for presymptomatic evaluation. | Limited to specialized centers. |