Magnetic resonance neurography appearance and diagnostic evaluation of peripheral nerve sheath tumors

Heng Zhai,Xi Liu,Yinzhang Lv,Xiangquan Kong,Dingxi Liu

doi:10.1038/s41598-019-43450-w

Abstract

Imaging appearances of peripheral nerve sheath tumors by MRI are difficult distinguish from soft-tissue tumors. The objective of this study was to evaluate the feasibility and imaging appearance of high-resolution 3-T magnetic resonance neurography (MRN) of the diagnosis of peripheral nerve sheath tumors (PNSTs) using sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences. We retrospectively evaluated the MRI and 3D Short tau inversion recovery sampling perfection with application-optimized contrasts using varying flip-angle evolutions (3D-STIR SPACE) sequences of 30 patients with PNSTs diagnosed by surgery and pathology. The contrast-enhanced 3D-STIR SPACE images were retrospectively analyzed and evaluated for the visualization of PNSTs. The tumors were evaluated by their number, location, morphology, size, signal intensity and enhancement characteristics. The imaging findings and characteristic signs of conventional MRI scanning and contrast-enhanced 3D-STIR SPACE sequences were compared. In these cases, conventional MRI images display the location, number, shape, size and signal characteristics of the lesions. These tumors were mostly solitary and had a well-defined boundary. Compared to conventional MRI images, imaging appearances including neurogenic origin, length of the peripheral nerves and relation to the nerve of PNSTs on 3D-STIR SPACE images were more accuracy (P < 0.05). Compared to 3D-STIR SPACE images, contrast-enhanced images can more clearly display background suppression of the peripheral nerves. The “split fat” sign and “target” sign were seen in some patients. 3D STIR SPACE sequences demonstrate its significant capacity to diagnostic evaluate and location of PNSTs. This article comprehensively reviews radiologic findings and illustrates the MRN features of PNSTs. 3D-STIR SPACE sequences be used for preoperative evaluation of PNSTs.

Highlights

Nerve sheath tumors are relatively common neurogenic tumors arising from nerve sheath cells
The peripheral nerve sheath tumors (PNSTs) were mainly located in the intermuscular space of the neck, extremities, paraspinal region, and retroperitoneal region
Among the 29 patients with benign peripheral nerve sheath tumors (BPNSTs), 12 patients had a tumor in the brachial plexus and its branches (Fig. 1), 9 patients had a tumor in the lumbar plexus and its branches (Fig. 2A–E), and 8 patients had a tumor in the sacral plexus and its branches (Fig. 3A–C)

Summary

Introduction

Nerve sheath tumors are relatively common neurogenic tumors arising from nerve sheath cells. The common types of peripheral nerve sheath tumors (PNSTs) include schwannomas, neurofibromas and malignant peripheral nerve sheath tumors (MPNSTs). Most of these tumors, such as schwannomas and neurofibromas, are benign upon histological examination[1,2,4]. Schwannomas and neurofibromas have more complete epineurium around them because they arise from nerve sheath cells and are separated from the involved nerves These two types of tumors share some magnetic resonance imaging (MRI) features. MRI has many advantages, such as being multidimensional, providing multiple sequences and having good soft-tissue resolution. It allows non-invasive and early identification of PNSTs10–12. It has unique advantages in the diagnosis of PNSTs and be used for presurgical localization

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Conclusion