Optimization of Brain MRI Images

    A major problem in current Image-Guided Minimally Invasive Neurosurgical procedures, such as the Thalamotomy and Pallidotomy, is that the target area is not directly visible in the pre-operative MRI images.
    The thalamotomy involves the resection or ablation of a specific area within the Thalamus, the Ventralis intermedius nucleus, or Vim nucleus. (shown in blue in the histological image, Figure(1)) However, as can be seen in the pre-operative MRI image (Figure(2)), the Thalamus is shown as a single grey structure. As a result, the surgeon must use electrical stimulation to determine the target areas exact location.
    We are working on new image analysis techniques which allow us to combine several images from different regions of the MR spectrum, ie. Spin-Lattice (T₁), Spin-Spin (T₂), Proton Density, Magnetization Transfer, and Diffussion to help delineate the various functional sub-structures of the Thalamus.
    Using these results, we hope to develop new and fast imaging methods which exploit the spectral differences and provide the surgeon with pre-operative images with the different functional Thalamic sub-structures clearly defined. It is hoped these images will decrease the amount of time the patient spends in surgery, and increase the procedure success rate.
 

Figure(1): Histological image of the Thalamus and Deep Brain. The Vim nucleus is shown in blue, as is the Globus Pallidus internus, GPi, the main target area in a Pallidotomy.

Figure(2): Typical Pre-Operative image, the thalamus is outlined in red.