Diffusion Tensor Tractography of the Corticospinal and Medial Lemniscus Pathways in Healthy Adults

Year 2025, Volume: 15 Issue: 4, 405 - 415, 20.12.2025

Zeynep Fırat , Gazanfer Ekinci

https://doi.org/10.31832/smj.1761230

Abstract

Objective: This study aims to visualize major brainstem white matter pathways in vivo through MR tractography, with a specific focus on the corticospinal tract (CST) and medial lemniscus (ML), which are essential motor and sensory tracts in healthy individuals.
Methods: Twenty right-handed healthy adults (10 females, 10 males; mean age: 29.95 ± 8.77 years) with normal brain MRI findings were included. DTI was acquired using a 3T MRI scanner. For each participant, CST and ML tracts were reconstructed bilaterally by placing regions of interest (ROIs) at anatomically defined points within the internal capsule and brainstem. Tracts fractional anisotropy (FA) values were calculated for quantitative assessment, and tract visual quality was scored independently by two observers using a 5-point scale.
Results: Tract reconstruction was successful in all participants. CSTs demonstrated consistently higher FA values and clearer anatomical delineation compared to ML tracts. Visual quality was independently rated by two experts using a 5-point scale. Mean CST scores were significantly higher than ML scores (p < 0.001), and inter-observer consistency was strong.
Conclusion: This study demonstrated that the CST and ML pathways can be reliably and anatomically accurately visualized in healthy individuals using ROI-based tractography. Establishing normative data for these vital brainstem tracts may serve as a valuable reference, particularly for neurological disorders or neurosurgical planning in which these pathways are likely to be affected.

Keywords

Diffusion tensor imaging (DTI) , Tractography , Corticospinal tract (CST) , Medial lemniscus (ML)

Ethical Statement

This study involved only human data; no animal experiments were conducted. Written informed consent was obtained from all participants prior to their inclusion. The study protocol was approved by the Yeditepe University Non-Interventional Clinical Research Ethics Committee (Approval No: 202507Y0883) and conducted in accordance with the principles outlined in the Declaration of Helsinki.

References

• Le Bihan D, Mangin JF, Poupon C, et al. Diffusion tensor imaging: Concepts and applications. J Magn Reson Imaging. 2001 Apr;13(4):534–46. doi:10.1002/jmri.1076
• Setsu Wakana, Hangyi Jiang, Lidia M Nagae-Poetscher, Peter C M van Zijl SM. Fiber tract-based atlas of human white matter anatomy. Radiology. 2004;230(1):77–87.
• Beaulieu C. The basis of anisotropic water diffusion in the nervous system - A technical review. NMR Biomed. 2002;15(7–8):435–55.
• Mori S, van Zijl PCM. Fiber tracking: Principles and strategies - a technical review. NMR Biomed. 2002 [cited 2014 Jul 26];15(7–8):468–80. doi:10.1002/nbm.781
• Jbabdi S, Johansen-Berg H. Tractography: Where do we go from here? Brain Connect. 2011 Jan [cited 2014 Nov 17];1(3):169–83. doi:10.1089/brain.2011.0033
• Catani M, Thiebaut de Schotten M. A diffusion tensor imaging tractography atlas for virtual in vivo dissections. Cortex. 2008 Sep [cited 2014 Jul 9];44(8):1105–32. doi:10.1016/j.cortex.2008.05.004
• Stieltjes B, Kaufmann WE, van Zijl PC, et al. Diffusion tensor imaging and axonal tracking in the human brainstem. Neuroimage. 2001 Sep [cited 2014 Dec 2];14(3):723–35. doi:10.1006/nimg.2001.0861
• Salamon N, Sicotte N, Alger J, et al. Analysis of the brain-stem white-matter tracts with diffusion tensor imaging. Neuroradiology. 2005;47:895–902.
• Sarsılmaz A, Fırat Z, Uluğ AM, et al. Diffusion tensor imaging in early amyotrophic lateral sclerosis using 3T magnetic resonance imaging. Neurol Sci Neurophysiol. 2018;35(2):102–7.
• Nucifora PGP, Verma R, Lee S-K, Melhem ER. Diffusion-tensor MR imaging and tractography: Exploring brain microstructure and connectivity. Radiology. 2007;245(2):367–84.
• Andrews DW. Functional neuroimaging: A clinical approach. In: Holodny AI, ed. Functional Neuroimaging. Vol. 37. New York, NY: Informa Healthcare USA, Inc; 1995:1227-1228
• Kovanlikaya I, Firat Z, Kovanlikaya A, et al. Assessment of the corticospinal tract alterations before and after resection of brainstem lesions using Diffusion Tensor Imaging (DTI) and tractography at 3T. Eur J Radiol. 2011 Mar [cited 2014 Dec 17];77(3):383–91. doi:10.1016/j.ejrad.2009.08.012
• Topcuoglu OM, Yaltirik CK, Firat Z, et al. Limited positive predictive value of diffusion tensor tractography in determining clinically relevant white matter damage in brain stem cavernous malformations: A retrospective study in a single center surgical cohort. J Neuroradiol. 2019.
• Rueda-Lopes FC, Hygino Da Cruz LC, Doring TM, Gasparetto EL. Diffusion-weighted imaging and demyelinating diseases: New aspects of an old advanced sequence. Am J Roentgenol. 2014;202(1):34–42.
• Zhylka A, Sollmann N, Kofler F, et al. Reconstruction of the corticospinal tract in patients with motor-eloquent high-grade gliomas using multilevel fiber tractography combined with functional motor cortex mapping. Am J Neuroradiol. 2023;44(3):283–90.
• Serra C, Türe H, Fırat Z, et al. Microsurgical management of midbrain gliomas: Surgical results and long-term outcome in a large, single-surgeon, consecutive series. J Neurosurg. 2024;140:104–115.
• Chen X, Weigel D, Ganslandt O, Buchfelder M, Nimsky C. Diffusion tensor imaging and white matter tractography in patients with brainstem lesions. Acta Neurochir (Wien). 2007 Nov [cited 2014 Dec 2];149(11):1117–31; discussion 1131. doi:10.1007/s00701-007-1282-2
• Ugurlu D, Firat Z, Türe U, Unal G. Neighborhood resolved fiber orientation distributions (NRFOD) in automatic labeling of white matter fiber pathways. Med Image Anal. 2018;46:130–45.
• Laundre BJ, Jellison BJ, Badie B, Alexander AL, Field AS. Diffusion tensor imaging of the corticospinal tract before and after mass resection as correlated with clinical motor findings: Preliminary data. AJNR Am J Neuroradiol. 2005;26(April):791–6.
• Kucukboyaci N, Leyden K, Kemmotsu K, et al. Better executive function associated with higher frontoparietal functional connectivity in the spared hemisphere in left Mesial Tle. Epilepsy Curr. 2015;15:183.
• Peng H, Cirstea CM, Kaufman CL, Frey SH. Microstructural integrity of corticospinal and medial lemniscus tracts: Insights from diffusion tensor tractography of right-hand amputees. J Neurophysiol. 2019;122(1):316–24.
• Jellison BJ, Field AS, Medow J, Lazar M, Salamat MS, Alexander AL. Diffusion tensor ımaging of cerebral white matter: A pictorial review of physics, fiber tract anatomy, and tumor imaging patterns. AJNR Am J Neuroradiol. 2004;25(March):356–69.
• Seo JP, Jang SH. Different characteristics of the corticospinal tract according to the cerebral origin: DTI study. Am J Neuroradiol. 2013;34(7):1359–63.
• Bennett IJ, Madden DJ. Disconnected aging: Cerebral white matter integrity and age-related differences in cognition. Neuroscience. 2014;276:187–205. doi:10.1016/j.neuroscience.2013.11.026
• Westlye LT, Walhovd KB, Dale AM, Bjørnerud A, Due-Tønnessen P, Engvig A, et al. Differentiating maturational and aging-related changes of the cerebral cortex by use of thickness and signal intensity. Neuroimage. 2010;52(1):172–85. doi:10.1016/j.neuroimage.2010.03.056
• Inano S, Takao H, Hayashi N, Abe O, Ohtomo K. Effects of age and gender on white matter integrity. Am J Neuroradiol. 2011;32(11):2103–9.
• Hsu JL, Van Hecke W, Bai CH, et al. Microstructural white matter changes in normal aging: A diffusion tensor imaging study with higher-order polynomial regression models. Neuroimage. 2010;49(1):32–43. doi:10.1016/j.neuroimage.2009.08.031
• Lebel C, Beaulieu C. Longitudinal development of human brain wiring continues from childhood into adulthood. J Neurosci. 2011;31(30):10937–47.
• Dubois J, Dehaene-Lambertz G, Perrin M, et al. Asynchrony of the early maturation of white matter bundles in healthy infants: Quantitative landmarks revealed noninvasively by diffusion tensor imaging. Hum Brain Mapp. 2008;29(1):14–27.
• Takao H, Hayashi N, Ohtomo K. White matter asymmetry in healthy individuals: A diffusion tensor imaging study using tract-based spatial statistics. Neuroscience. 2011;193:291–9. doi:10.1016/j.neuroscience.2011.07.041
• Besseling RMH, Jansen JFA, Overvliet GM, et al. Tract specific reproducibility of tractography based morphology and diffusion metrics. PLoS One. 2012;7(4).
• Yamada K, Sakai K, Akazawa K, Yuen S, Nishimura T. MR tractography: A review of its clinical applications. Magn Reson Med Sci. 2009;8(4):165–74.
• Yeh FC, Zaydan IM, Suski VR, et al. Differential tractography as a track-based biomarker for neuronal injury. Neuroimage. 2019;202(August):116131. doi:10.1016/j.neuroimage.2019.116131
• Wasserthal J, Neher P, Maier-Hein KH. TractSeg - Fast and accurate white matter tract segmentation. Neuroimage. 2018;183(March):239–53. doi:10.1016/j.neuroimage.2018.07.070