Exploring the diagnostic performances of CISS and DESS in visualizing extracranial nerves and localizing parotid tumors

Motivation: Identification of the spatial relationship between the parotid tumor and the extracranial segment of the facial nerve can facilitate preoperative planning. Goal(s): We compared image quality and diagnostic efficacy between double-echo steady-state with water (DESS) and constructive interference in steady-state (CISS) sequences. Approach: DESS and CISS sequences were used to determine the visibility of the extracranial segment of the facial nerve in healthy volunteers, then locate parotid tumors and facilitate patient diagnosis. Results: Compared with DESS images, CISS images more reliably showed the location of the facial nerve relative to the lesion in patients with parotid tumorsImpact: CISS demonstrates good visualization of the parotid branches (temporofacial and cervicofacial trunks) compared with DESS. Moreover, CISS is a reliable and direct method for identifying the locations of parotid tumors.