Fast 3 T nigral hyperintensity magnetic resonance imaging in Parkinson’s disease

Abstract

The absence of nigral hyperintensity is a promising MR marker for Parkinson’s disease (PD), but its small size imposes limitations on its routine use. Our aim was to compare Multi Echo Data Image Combination (MEDIC), segmented echo-planar imaging (EPISEG) and fluid-attenuated inversion recovery (FLAIR) sequences, as well as both magnitude (MAG) and susceptibility-weighted imaging (SWI) reconstructions of single-echo gradient echo for nigral hyperintensity imaging. Twenty-five healthy and twenty PD subjects were included. Sensitivity to motion artefacts, confidence of the radiologist in interpretation, rate of nondiagnostic scans and diagnostic accuracy were assessed. EPISEG was less motion-sensitive than MEDIC, MAG, and SWI, while FLAIR was less motion-sensitive than MAG and SWI. The reviewers were more confident when using EPISEG compared to any other techniques and MEDIC was superior to FLAIR. The proportions of nondiagnostic scans were lower for EPISEG than for other sequences. The best diagnostic performance was achieved for EPISEG (sensitivity = 65%, specificity = 96%). Using EPISEG, the absence of nigral hyperintensity in PD was associated with higher Hoehn-Yahr stage and MDS-UPDRS II + III. Nigral hyperintensity may be intact at the very early stages of PD. The promising properties of EPISEG may help the transfer of nigral hyperintensity imaging into daily clinical practice.

Neuroimaging in Parkinson’s Disease: necessity or exaggeration?

“…According to a recent meta-analysis, the overall sensitivity and specificity of N-1 imaging on 3T MRI was comparable to that of 7T MRI, and both exceeded 94% [30]. However, poor visualisation of N-1 may also be caused by inappropriate scanning techniques (acquisition plane, slice thickness, parameters and the type of iron-sensitive sequence used) and/or technical artifacts, especially those caused by movement or magnetic field distortions [32]. Visual rating of DNH is subjective and observer-dependent, and in this regard the experience of the radiologist is essential.…”