Clinical Applications for Diffusion MRI and Tractography of Cranial Nerves Within the Posterior Fossa: A Systematic Review

Frontiers in Neuroscience

Robert Bradford¹  Sjoerd B. Vos²  Sotirios Bisdas³  Sebastien Ourselin⁴  Jonathan Shapey⁴  Tom Vercauteren⁴  Shakeel R. Saeed⁶ 

[1] Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, United Kingdom;Epilepsy Society MRI Unit, Chalfont St Peter, United Kingdom;Neuroimaging Analysis Centre, London, United Kingdom;School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom;The Ear Institute, University College London, London, United Kingdom;The Royal National Throat, Nose and Ear Hospital, London, United Kingdom;Translational Imaging Group—Centre for Medical Image Computing, University College London, London, United Kingdom;Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom;

关键词: MRI—magnetic resonance imaging;    diffusion MRI (dMRI);    tractography;    cranial nerves;    brain tumors;    trigeminal neuralgia (TN);   

DOI  :  10.3389/fnins.2019.00023

来源: DOAJ

【 摘 要 】

Objective: This paper presents a systematic review of diffusion MRI (dMRI) and tractography of cranial nerves within the posterior fossa. We assess the effectiveness of the diffusion imaging methods used and examine their clinical applications.Methods: The Pubmed, Web of Science and EMBASE databases were searched from January 1st 1997 to December 11th 2017 to identify relevant publications. Any study reporting the use of diffusion imaging and/or tractography in patients with confirmed cranial nerve pathology was eligible for selection. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) tool.Results: We included 41 studies comprising 16 studies of patients with trigeminal neuralgia (TN), 22 studies of patients with a posterior fossa tumor and three studies of patients with other pathologies. Most acquisition protocols used single-shot echo planar imaging (88%) with a single b-value of 1,000 s/mm2 (78%) but there was significant variation in the number of gradient directions, in-plane resolution, and slice thickness between studies. dMRI of the trigeminal nerve generated interpretable data in all cases. Analysis of diffusivity measurements found significantly lower fractional anisotropy (FA) values within the root entry zone of nerves affected by TN and FA values were significantly lower in patients with multiple sclerosis. Diffusivity values within the trigeminal nerve correlate with the effectiveness of surgical treatment and there is some evidence that pre-operative measurements may be predictive of treatment outcome. Fiber tractography was performed in 30 studies (73%). Most studies evaluating fiber tractography involved patients with a vestibular schwannoma (82%) and focused on generating tractography of the facial nerve to assist with surgical planning. Deterministic tractography using diffusion tensor imaging was performed in 93% of cases but the reported success rate and accuracy of generating fiber tracts from the acquired diffusion data varied considerably.Conclusions: dMRI has the potential to inform our understanding of the microstructural changes that occur within the cranial nerves in various pathologies. Cranial nerve tractography is a promising technique but new avenues of using dMRI should be explored to optimize and improve its reliability.

【 授权许可】

Unknown