Diffusion-weighted imaging and diffusion tensor imaging as adjuncts toconventional MRI for the diagnosis and management of peripheral nerve sheath tumors: current perspectives and future directions

Peripheral nerve sheath tumors (PNSTs) account for 5% of soft tissue neoplasms and are responsible for a wide spectrum of morbidities ranging from localized neuropathy to fulminant metastatic spread and death. MR imaging represents the gold standard for identification of these neoplasms, however, current anatomic MR imaging markers do not reliably detect or differentiate benign and malignant lesions, and therefore, biopsy or excision is required for definitive diagnosis. Diffusion-weighted MR imaging (DWI) serves as a useful tool in the evaluation and management of PNSTs by providing functional information regarding the degree of diffusion, while diffusion tensor imaging (DTI) aids in determining the directional information of predominant diffusion and has been shown to be particularly useful for pre-operative planning of these tumors by delineating healthy and pathologic fascicles. The article focuses on these important neurogenic lesions, highlighting the current utility of diffusion MR imaging and future directions including computerized radiomic analysis.Key Points center dot Anatomic MRI is moderately accurate in differentiating benign from malignant PNST.center dot Diffusion tensor imaging facilitates pre-operative planning of PNSTs by depicting neuropathy and tractography.center dot Radiomics will likely augment current observer-based diagnostic criteria for PNSTs.