Quantitative T 1 mapping of the substantia nigra using phase-sensitive inversion recovery sequence at 3.0-T: a healthy volunteer study

Abstract

Background

Quantitative evaluation of degeneration of the substantia nigra (SN) is important for early, pre-symptomatic diagnosis of Parkinson’s disease (PD). Accordingly, a clinically feasible imaging and quantification technique are needed.

Purpose

To investigate the T₁ value of the SN in healthy individuals from phase-sensitive inversion recovery (PSIR) images and to clarify its correlation with the SN characteristics on neuromelanin (NM) images to identify an imaging biomarker for early diagnosis of PD.

Material and Methods

T₁-weighted and NM images of the SN from 32 healthy volunteers were obtained using PSIR and turbo spin-echo sequences. The contrast between the SN and cerebral peduncle (CP) and area of the SN were measured; the T₁ values of the SN from PSIR images and relationships between the T₁ value and age/SN area were evaluated.

Results

There was a significant negative correlation between age and the SN area obtained using PSIR imaging. The SN area on PSIR images (104.9 ± 20.9 mm²) was significantly larger than that on NM images (72.1 ± 14.9 mm²). There was a significant negative correlation between the SN area and the T₁ value of the SN obtained from PSIR images.

Conclusion

In healthy adults, the area and T₁ value of the SN measured on PSIR images were different from those obtained from NM images. This suggests that PSIR imaging may help in the assessment of SN degeneration.