May-June 2017
Introduction

MR Neurography: State of the Art

Chhabra pic

Avneesh Chhabra

It is my pleasure to write an editorial for this exciting AJNR News Digest on the topic of MR neurography (MRN). MRN has come a long way since its introduction in 1992 by Howe et al.1 Several technical developments have occurred in this domain over the last decade,2–6 and the increasing use of MRN has impacted and considerably changed the practice of neurology, neurosurgery, and plastic surgery as it pertains to the diagnostic evaluation and treatment of peripheral neuropathy and plexopathy.7–11

High-resolution isotropic 3D imaging with thick-slab isotropic MIPs delineates the brachial plexus nerves in multiple arbitrary planes, as shown by Vargas et al12 and our group.13 3D variable turbo factor spin-echo imaging partially mitigates vascular signal contamination in the vicinity of the nerves. Near-complete vascular signal suppression for MRN is successfully achieved using 1 of these methods: reversed fast imaging with steady-state free precession sequence, high-b-value diffusion imaging, and addition of motion sensitive driven equilibrium to 3D Dixon or 3D spectral-attenuated inversion recovery imaging.14 Such nerve-selective images reconstructed along the long axis of the nerve lead to increased conspicuity of nerve abnormalities, such as intraneural signal and fascicular and/or caliber alterations.15 The extents of the neuroma and nerve gap are also well-delineated and characterized. The accuracy of MRN for both small and large nerves has been well-established in multiple scientific studies.16–19

Lumbosacral (LS) plexus anatomy is complicated, and the branch nerves course obliquely from their origins to innervate the extremities. Cho Sims et al20 recently showed that 3D isotropic vascular and fat signal-suppressed imaging selectively demonstrates LS plexus anatomy when the images are reconstructed in specific angular planes in sagittal and coronal orientations. Plexus and peripheral nerves can be affected by several diffuse … more »

Head & Neck

Visualization of the Peripheral Branches of the Mandibular Division of the Trigeminal Nerve on 3D Double-Echo Steady-State with Water Excitation Sequence

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Hiroyuki Fujii

Cranial nerve impairments can significantly compromise functionality and quality of life. Knowledge of the anatomic course of each cranial nerve and its relationship with surrounding structures is important for diagnosing various cranial pathologies and preventing complications from surgical interventions.

Despite recent advances … more »

Spine

Characterization of Peripheral Nerve Sheath Tumors with 3T Proton MR Spectroscopy

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Laura M. Fayad

My research has focused on advancing MR imaging techniques, especially noncontrast techniques, for various applications in musculoskeletal tumor imaging, including the detection, characterization, and assessment of treatment response and the differentiation of postsurgical nodular scar from recurrence. A particular challenge … more »