Magnetization transfer ratio in early period of Parkinson disease

The aim of this study is to determine the role of magnetization transfer ratio (MTR) in the early period of Parkinson disease (PD).

Clinically diagnosed 33 patients with PD in the first year of diagnosis, and 30 healthy volunteers were assessed. Magnetic resonance imaging (MRI) was performed without and with magnetization transfer (MT) imaging. Signal intensity measurements were obtained from 15 anatomic regions (substantia nigra pars compacta [SNPC], substantia nigra pars reticulate [SNPR], red nucleus, dentate nucleus, cerebellum, pons, globus pallidus, putamen, caudate nucleus, thalamus, internal capsule posterior horn, forceps major, forceps minor, and genu and splenium of corpus callosum) and MTR was calculated. Comparisons of the findings between each anatomic location of the patients with PD and normal subjects were performed.

Most prominent decrease of MTR was found in SNPC (p < 0.001). A significant decrease of MTR was also found in the SNPR (p = 0.006), red nucleus (p = 0.037), and pons (p = 0.046). The other regions lack significance.

MTR analysis is a useful technique for initial PD assessment. Even in the first year of diagnosis, significant reduction of MTR is found in substantia nigra, red nucleus, and pons compared with that of the control group.