Diffusion tensor based forearm nerve tractography in 1.5 T MRI

Abstract

Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) method for efficient nerve pathways visualization. DTI, particularly of peripheral nerves, is commonly performed in 3 T scanners. An often more accessible 1.5 T scanners are less likely to be chosen for DTI examinations due to generally lower image quality. Novel radiofrequency (RF) coils can help improve the signal to noise ratio in MRI and thus improve image quality. This study preliminary results of the feasibility and outcomes assessment of DTI-based tractography of the forearm nerves employing a novel coil design in 1.5 T scanners. The proposed scanning protocol includes the use of a metamaterial-inspired RF coil, a common DTI pulse sequence and a 3D T1-weighted morphological reference pulse sequence. The protocol is tested on three healthy volunteers. Two tract bundles corresponding to median and ulnar nerves of the forearm are reliably reconstructed in all subjects. The results show that with an appropriate choice of RF coil and pulse sequence parameters forearm DTI studies can be performed in 1.5 T scanners with sufficient quality making such examination more accessible for clinical use.