Clinical applications of brain diffusion-tensor imaging and fiber tractography

Background
Diffusion-tensor imaging (DTI) and fiber tractography are relatively recent MRI techniques that have opened an entirely new noninvasive window on the white matter (WM) connectivity of the human brain. Since their introduction, they have rapidly evolved and found application in essentially every disorder involving the WM.


Aim
The aim of this work was to study the clinical applications of DTI and fiber tractography in various neoplastic and nonneoplastic brain lesions, as well as to demonstrate their role in preoperative mapping of WM tracts in relation to brain lesions.


Patients and methods
A prospective study was conducted for 2 years on 40 patients presenting to Alexandria University with variable intracranial lesions related to WM tracts who underwent DTI and fiber tractography. The study included 25 males and 15 females. The age of the patients ranged from 6 to 76 years (mean age, 40.7 years). Qualitative analysis of DTI data was performed using directionally encoded color maps and three-dimensional tractography reconstruction.


Results
According to visual analysis multiple projection, association and/or commissural WM fiber tracts were involved; the most common was the corticospinal tract in 25 (62.5%) cases. WM tract involvement patterns were deviated/splayed tracts in 31 (64.6%) cases, infiltrated in nine (18.8%) cases, edematous in five (10.4%) cases, and interrupted in three (6.3%) cases.


Conclusion
DTI and fiber tractography are valuable noninvasive techniques providing qualitative information aiding in lesion characterization, determining WM integrity, and essential in the surgical planning for patients with intrinsic brain lesions.