Dynamic MRI of the vocal cords using phased-array coils: A feasibility study

Abstract

Objective:Endoscopy for evaluation of hoarseness is an invasive procedure and the result depends, to a large extent, on the patient's cooperation. Successful laryngoscopy can also be hampered by unfavourable anatomic conditions, a severely impaired general condition, or severe coagulopathy. We evaluated the feasibility of doing ultra-fast magnetic resonance imaging (MRI), using a recent dedicated coil design and a sequence with inherently high signal-to-noise ratios (SNR), for the detection of motility disorders of the vocal cords.Materials and Methods:Twelve consecutive patients (eight males and four females) in the age range of 24–80 years (mean age 60 years) with persistent hoarseness and presumed vocal cord palsy were included in this blinded prospective study. Two two-element phased-array carotid coils were used for signal reception. The first coronal real-time steady-state free precession (SSFP) sequence was performed during silence (i.e., with no vocal cord motion) and the second while phonating ‘heee.’ Qualitative MRI findings were compared with the results of the endoscopic examination.Results:The examination time for setup, patient instruction and positioning, localization scans, and real-time SSFP scans was less than 10 min. Seven patients with laryngoscopically-confirmed unilateral palsy of the vocal cord were correctly identified with MRI. The five remaining patients had hoarseness due to causes other than vocal cord palsy; they showed normal motion of the vocal cords on MRI and endoscopy.Conclusion:Compared to preceding studies, the image quality in this study is supported by excellent SNR (carotid phased-array coils and SSFP sequence with higher SNR if compared to a spoiled gradient-echo sequence or an EPI sequence). Further studies, with larger groups of patients, are necessary to show if this protocol can serve as an alternative to endoscopy in selected cases.