Feasibility of vocal fold abduction and adduction assessment using cine-MRI

Marina Mat Baki,Shonit Punwani,David Atkinson,Nicola Stevenson,Georgekutty Naduvilethil,Alex Menys,Martin A Birchall,Simon Morley,Timothy Beale,Paul Bassett,Guri Sandhu

doi:10.1007/s00330-016-4341-3

Abstract

ObjectiveDetermine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI)MethodsCine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC).ResultsVF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44).ConclusionCine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability.Key points• Cine-MRI is used to assess vocal folds (VFs) mobility: abduction and adduction.• New quantitative metrics are derived from VF position and abduction potential.• Cine-MRI able to depict the difference between normal and abnormal VF mobility.• Cine-MRI derived quantitative metrics have good repeatability.

Highlights

IntroductionThe larynx has a pair vocal folds (VFs) that open (abduct) during respiration and close (adduct) during speech or phonation
The larynx has a pair vocal folds (VFs) that open during respiration and close during speech or phonation
VF phonation asymmetry (VFPa) and VF respiration asymmetry (VFRa) were significantly higher for unilateral VF paralysis (UVFP) patients compared with healthy volunteers (p

Summary

Introduction

The larynx has a pair vocal folds (VFs) that open (abduct) during respiration and close (adduct) during speech or phonation. VF immobility caused by nerve injury or paralysis is detected during this routine scope examination. Injury to the vagus nerve or its branch of the recurrent laryngeal nerve (RLN) causes vocal fold paralysis. Eur Radiol (2017) 27:598–606 aetiologies of vocal fold paralysis include iatrogenic (36 %), neoplastic (18 %), and idiopathic (18 %) in which unilateral is more common than bilateral paralysis (78 % and 22 %, respectively) [1]. Other less common causes are trauma, aortic aneurysm, radiation induced, and cardiovascular pathology. Risk of permanent RLN palsy following thyroidectomy has been estimated at 1-2 % [5], but this may be a considerable underestimate due to problems of follow-up and reporting

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Conclusion