Magnetic resonance tractography based on the constrained spherical deconvolution in patients with gliomas of the optic pathway

Abstract

Background: The use of magnetic resonance (MR) tractography in neurosurgery is becoming an increasingly common practice for noninvasive imaging of white matter pathways. The most common method of tract reconstruction is the deterministic algorithm of diffusion tensor magnetic resonance imaging (MRI). However, this method of reconstructing pathways has a number of significant limitations. The most important of them are the lack of the possibility of visualizing the intersecting fibers, the complexity of building tracts in the area of perifocal edema and in the immediate vicinity of the tumor borders. The method of MR tractography, based on obtaining a diffusion image with a high angular resolution (High Angular Resolution Diffusion Imaging, HARDI), using the constrained spherical deconvolution (CSD) algorithm for post-processing of data, makes it possible to avoid these disadvantages. Relatively recently, a new algorithm, Single-Shell 3-Tissue CSD (SS3TCSD), has been proposed for processing HARDI data, which has the potential to improve the reconstructing of pathways in the area of perifocal edema or edema-infiltration.Aim: To evaluate the potential of the new SS3TCSD algorithm compared to ST-CSD (Single-Tissue CSD) in the imaging of the optic radiation and visual tracts in patients with gliomas.Materials and methods: Diffusion and routine brain MRI was performed in 10 patients with newly diagnosed cerebral gliomas, followed by reconstruction of the optic radiation and visual tracts. We compared new algorithms for postprocessing MR tractography (ST-CSD and SS3TCSD) in imaging of the optic tract and visual radiation in patients with brain gliomas affecting various parts of the visual system.Results: The SS3T-CSD method showed a lower mean percentage of false positive tracts compared to the ST-CSD method: 19.75% for the SS3T-CSD method and 80.32% for the ST-CSD method in cases of proximity of the tumor to the tracts, 5.27% for the SS3T-CSD method and 25.27% for the STCSD method in cases of reconstructing tracts in healthy white matter.Conclusion: The SS3T-CSD method has a number of advantages over ST-CSD and allows for successful imaging of the optic pathways that have a complex structure and repeatedly change direction along their course.

Significance of the Corpus Callosum and Inferior Fronto-Occipital Fasciculus in Recovery after Traumatic Brain Injury

“…According to K. Schilling and coauthors (Schilling et al 2019), a similar number of fibers were false positive in HARDI CSD tractography with the settings similar to those used in our work. Our previous experience in fiber tracking demonstrated that false-positive fibers usually did not form thick bundles (Baev et al 2021) and that the brightness of the tractogram voxels for falsepositive fibers tended to be low.…”

Diffusion-tensor and Diffusion-kurtosis Magnetic Resonance Imaging in the Assessment of Diffuse Axonal Injury (Literature Review)

“…Алгоритм FACT получил распространение вследствие высокой информативности, простоты проведения и постобработки. С помощью этой модели в каждом вокселе возможно оценить только одно направление волокна [1]. Однако ранее было доказано, что до 90 % вокселей белого вещества в головном мозге содержат пересекающиеся волокна [13].…”