Reconstruction of the corticorubral tract in the human brain using diffusion tensor tractography.

The corticorubral tract (CRT) facilitates fine motor coordination. However, no diffusion tensor tractography (DTT) study has been conducted although a few studies have reported on the cortical connection of the red nucleus. In this study, we investigated the DTT reconstruction method and DTT characteristics of the CRT in normal subjects. Thirty-six right-handed normal subjects were recruited. Diffusion tensor images were scanned using a 1.5 T MRI scanner. For analysis of the CRT, the seed region of interest (ROI) was placed on the red nucleus of the midbrain, and the target ROI was placed on the primary sensorimotor cortex. Values of fractional anisotropy (FA), mean diffusivity (MD), and tract volume (TV) of the CRT were obtained for both hemispheres. Among the 72 cerebral hemispheres of the 36 normal subjects, the neural tract between the red nucleus and the primary sensorimotor cortex was reconstructed in 66 hemispheres (92%). The reconstructed CRT, which originated from the primary sensorimotor cortex, descended through the posterior portion of the centrum semiovale, the corona radiata and posterior limb of the internal capsule, and terminated at the red nucleus. Analysis of the FA, MD, and TV values revealed no significant differences between the right and left hemispheres (p > 0.05). We describe the method of DTT reconstruction and the imaging parameters of the CRT in the brain of normal subjects. We believe that the DTT method and associated parameter results for the CRT in normal subjects will be useful in future neuroscience studies.