Segmentation of the thalamus in MRI based on T1 and T2

Generation of Individualized Thalamus Target Maps by Using Statistical Shape Models and Thalamocortical Tractography

“…[4][5][6][7][8] In parallel to the effort of providing stereotactic atlases that incorporate clinical imaging-based anatomic correspondences, 9 it is desirable to optimize MR imaging sequences and image-processing techniques for the direct identification of thalamic nuclei. [10][11][12] A promising technique to noninvasively chart the human thalamus is diffusion tensor imaging 13 and subsequent probabilistic tractography, which can be applied to map the networks of thalamocortical connectivity. [14][15][16] Such methods are based on the fact that various thalamic nuclei present differential interconnections; therefore, this information can be used to subdivide the thalamus into domains that have different dominant connections with preselected cortical domains.…”

Treatment of Chronic Pain: Diffusion Tensor Imaging Identification of the Ventroposterolateral Nucleus Confirmed with Successful Deep Brain Stimulation

“…Although the same algorithm and similar FA threshold values were used for FT, slight differences were observed in the images regarding the localization and shape of the VPL nucleus between subjects and even nuclei in the same subject. We think that this observation may be due to the anatomical variability of the thalamic nuclei as pointed out above [4,5,16], although it is impossible to rule out some inherent technical problems of FT and MR echo-planar imaging, which might be the cause of this observation.…”

“…Conventional MR imaging is not yet capable of directly visualizing these thalamic nuclei [4,5,21]. On the other hand, probabilistic tractography obtained through post-processing of DTI data has been able to successfully segment the thalamus on the basis of its connectivity to various regions of the cerebral cortex [4,6,11,22,23].…”

“…Since conventional MRI is not able to identify thalamic nuclei in detail yet, DBS treatment of pain usually relies on indirect targeting based on atlas-derived coordinates. Although indirect targeting of the thalamus is generally robust, variability in anatomy and function of thalamic nuclei across individuals and across disease states would suggest that methods to identify patient-specific targets could enhance the safety and efficacy of DBS surgery [4,5,6]. …”

Direct Visualization of Anatomic Subfields within the Superior Aspect of the Human Lateral Thalamus by MRI at 7T

“…However, as long as differences in contrast-relevant tissue properties exist, their delineation by an appropriate MR imaging technique is mainly a question of SNR. Several years ago, the wide availability of 3T MR imaging scanners triggered a series of studies aiming to visualize internal substructures of the thalamus, [4][5][6][7][8][9][10][11] extending the research done at 1.5T. [12][13][14][15][16] Although noticeable progress was made, the visualization of thalamic nuclei with 3T MR imaging for DBS surgery is not a clinical routine to date.…”