Neuromelanin magnetic resonance imaging of locus ceruleus and substantia nigra in Parkinson's disease

Abstract

We carried out an investigation to identify neuromelanin-containing noradrenergic and dopaminergic neurons in the locus ceruleus and substantia nigra pars compacta of healthy volunteers and patients with Parkinson's disease using a newly developed magnetic resonance imaging technique that can demonstrate neuromelanin-related contrast. The high-resolution neuromelanin images obtained by a 3-T scanner revealed high signal areas in the brain stem and these corresponded well with the location of the locus ceruleus and substantia nigra pars compacta in gross specimens. In Parkinson's disease patients, the signal intensity in the locus ceruleus and substantia nigra pars compacta was greatly reduced, suggesting depletion of neuromelanin-containing neurons. We conclude that neuromelanin magnetic resonance imaging can be used for direct visualization of the locus ceruleus and substantia nigra pars compacta, and may help in detecting pathological changes in Parkinson's disease and related disorders.

3D neuromelanin-sensitive magnetic resonance imaging with semi-automated volume measurement of the substantia nigra pars compacta for diagnosis of Parkinson’s disease

“…Although our method could not discriminate 2 groups perfectly (i.e., there were overlaps in SNc volumes), it could discriminate PD patients from control subjects with almost equal or better performance compared with other imaging methods, such as contrast ratio method using neuromelanin images [7,8], and diffusion-kurtosis imaging [16]. Therefore, our method can be potentially used for clinical diagnosis of PD patients, especially for early stage.…”

“…In contrast to 3D, 2D FSE acquisition has been used for most neuromelanin-sensitive MRI [7,12]. 2D FSE uses many refocusing pulses, which has a 13 MT effect.…”

“…There are several studies which report investigation of the SNc using neuromelanin-sensitive MRI [6][7][8]. However, most of the previous reports used a 2 5 dimensional (2D) fast spin echo (FSE) sequence, which provides subjective measurements of signal or volume using user-defined region-of-interest (ROI).…”

A Neural Model of Mind Wandering

“…Using structural magnetic resonance imaging, the LC cannot be seen on standard structural scans [54]; LCtailored MRI structural sequences are required to accurately localize the LC. Recently, the first in vivo anatomical map of the human LC in standard space was created [55] using a T1-TSE sequence [54] that exploited the increased contrast that the presence of neuromelanin in the LC offers. This method was later validated with post-mortem scans and histology ( [56], see Figure I).…”

Imaging in Parkinson's Disease

“…T1-weighted "neuromelanin-sensitive" MRI sequences have been developed to identify and characterize the substantia nigra pars compacta and locus coeruleus in vivo in PD (Ohtsuka et al, 2013;Sasaki et al, 2006). Loss of neuromelanin-related signal intensity in the substantia nigra pars compacta was observed in PD patients and correlated H&Y stages (Kashihara, Shinya, & Higaki, 2011;Matsuura et al, 2013;Schwarz et al, 2011).…”