Human subthalamic nucleus: evaluation with high-resolution MR imaging at 3.0 T.

INTRODUCTION

The purpose of this study was to compare the visibility of the normal subthalamic nucleus (STN) between fast spin-echo T2-weighted (FSE T2-W) images and fast short inversion time inversion-recovery (FSTIR) images, and to assess the age-related changes of the STN at 3.0 T.

METHODS

We evaluated high-resolution FSE T2-W and FSTIR images in 24 neurologically normal subjects. Using both sequences, we assessed the visibility of the margins of the STN, and calculated the difference in signal intensity between the STN and structures adjacent to the STN. Then, to assess the age-related changes of the STN, we calculated the contrast-to-noise ratio between the STN and the white matter, and measured the position, length, and height of the STN. All data were statistically evaluated.

RESULTS

The visibility of the lower margin of the STN was significantly better on the FSTIR images than on the FSE T2-W images (P = 0.0001), while the visibility of other margins was significantly better on the FSE T2-W images than on the FSTIR mages (P = 0.002). The difference in signal intensity between the STN and substantia nigra was significantly greater on the FSTIR images than on the FSE T2-W images (P < 0.0001). The distance from the midline to the lateral border of the STN increased with age (FSE T2-W images: left r = 0.4916, P = 0.015; right r = 0.4442, P = 0.030).

CONCLUSION

The combined reading of both FSE T2-W and FSTIR images at 3 T will improve the identification of the STN. The age-related positional change of the STN should be considered in target determination for deep brain stimulation procedures.