The value of magnetic resonance imaging of the mandibular nerve using a micro surface coil and three-dimensional double-echo steady-state with water excitation sequence

Abstract

Objective To explore the value of small surface coil combined with three-dimensional double-echo steady-state with water excitation (3D-DESS-WE) sequence in displaying mandibular nerves and their branches. Methods The maxillofacial regions of 52 volunteers were scanned unilaterally by a small surface coil combined with 3D-DESS-WE sequence. According to the Gray's anatomy atlas, MPR and CPR was done according to the anatomic position of mandibular nerve and the branches, the signal characteristics of the nerves and neighboring structures were analyzed. The displaying rate of the mandibular nerves and their branches were evaluated.The image quality and display of the nerve were subjectively scored. The signal intensity(SI) of the nerve and adjacent lateral pterygoid muscle were measured. The signal intensity ratio(SIR) of mandibular nerve/lateral pterygoid muscle (SIRN/M) was calculated. Results Compared with the muscles, the nerve showed iso-signal intensity. The subjective scores for all small coil 3D-DESS-WE images were 3.02±0.82. The displaying rates of V3 trunk, anterior trunk, buccal nerve, posterior trunk, inferior alveolar nerve and lingual nerve were all 100%. V3 posterior trunk, inferior alveolar nerve and lingual nerve showed the best quality scores, which were all about 3 points, and the SIRN/M were about 1. The auricular temporal nerve and masseter muscle nerve were also basically satisfied. The displaying rate of mylohyoid muscle nerve, medial pterygoid nerve and lateral pterygoid nerve was low. Conclusion Small surface coil combine with 3D-DESS-WE sequence performed high-quality in mandibular nerves and their branches MR imaging using MPR, CPR post-processing technology, which are suitable for clinical application. Key words: Mandibular nerve; Magnetic resonance imaging; Small surface coil