Tract-by-tract morphometric and diffusivity analyses in vivo of spinocerebellar degeneration.

BACKGROUND AND PURPOSE

Three-dimensional anisotropy contrast (3DAC) based on a periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) sequence on a 3.0 T system is a new magnetic resonance imaging technique capable of providing images with significantly high anatomical resolution. The purpose of this study was to confirm whether this technique can characterize the degenerative processes in the brainstem of patients with spinocerebellar degeneration (SCD).

METHODS

3DAC images of 13 patients with multiple system atrophy with predominant cerebellar symptoms (MSA-C) and seven International Cooperative Ataxia Rating Scale (ICARS) score-matched patients with Machado-Joseph disease (MJD) were created using a diffusion-weighted PROPELLER sequence on a 3.0T system. The section of the middle pons was chosen for morphometric and diffusivity analyses.

RESULTS

The above analyses showed that atrophy and increased diffusivity of the ventral portion of the pons indicated MSA-C, whereas atrophy and increased diffusivity of the pontine tegmentum indicated MJD. Furthermore, ICARS scores significantly correlated with both the severities of the pontine atrophy and the mean diffusivity values of the ventral pontocerebellar tracts.

CONCLUSIONS

This study demonstrated that 3DAC PROPELLER on a 3.0T system enables in vivo "tract by tract" quantitative analysis of pontine degeneration in SCD.