Diffusion-tensor Imaging and Tractography Application in Pre-operative Planning of Intra-axial Brain Lesions.

Neetu Soni,Sanjay Behari,Anant Mehrotra,Sunil Kumar,Nishant Gupta

doi:10.7759/cureus.1739

Abstract

Gliomas are the most common brain tumors that diffusely infiltrate the surrounding white matter (WM) tracts. Conventional MRI is commonly used for tumor localization and characterization. However, this does not give precise information about the WM infiltration surrounding the tumor. Diffusion-tensor imaging (DTI) is a non-invasive magnetic resonance (MR) technique that measures WM tissue integrity and tractography (fiber tracking) used to investigate the preferential directionality of diffusion. DTI allows visualization of WM tracts in the immediate vicinity of brain tumors that permit maximum tumor resection while also preserving the eloquent brain areas. The relation of tumors with the white matter tracts (deviation, infiltration, and disruption) has been one the most important initial applications of DTI. The fibers can be infiltrated in normal-appearing areas, and abnormal-appearing areas of the brain can show anatomically intact fibers. In the surgical planning of brain tumors, surgery is aided by knowing the proximity and relative position of the tumor to the adjacent WM tracts. The aim of the present study is to assess the role of DT tractography (DTT) in preoperative mapping of major WM tracts in relation to brain tumors.

Highlights

In brain tumor patients, pre-operative surgical planning and assessment of the surrounding white matter (WM) tracts is a very important step to allow complete resection of tumor, while at the same time avoiding recurrence and loss of vital brain functions such as motor, sensory, auditory, language, and visual fields
The aim of the present study is to assess the role of DT tractography (DTT) in preoperative mapping of major WM tracts in relation to brain tumors
Diffusion-tensor imaging (DTI) is derived from diffusion-weighted imaging (DWI), which is based on the random water diffusion in each voxel

Summary

Introduction

Pre-operative surgical planning and assessment of the surrounding white matter (WM) tracts is a very important step to allow complete resection of tumor, while at the same time avoiding recurrence and loss of vital brain functions such as motor, sensory, auditory, language, and visual fields. Conventional MRI (cMRI) routinely demonstrates the lesion without any precise information about the involvement and integrity of the white matter tracts surrounding tumors [1]. Diffusion-tensor imaging with tractography (DTI) is currently the only available tool which displays the WM tracts disruption by fractional anisotropy (FA) changes and fibers reconstruction in patients with malignant brain tumors. It is very critical to accurately localize the WM tracts for preoperative surgical planning and making the decision of whether to operate or not [2]. The DTI adds directional information and provides three maps: quantitative apparent diffusion coefficient (ADC), the FA map, and the directionally encoded color-coded map (DEC).The ADC is a voxel-by-voxel measure of the magnitude of

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