Ultrasound Elastography Detects Age-Related Changes in Adult False Vocal Folds

Objectives: The purpose of this study was to investigate if ultrasound elastography could be used to noninvasively assess the stiffness, function, and symmetry of adult false vocal folds (FVF). To our knowledge, this is the first report of ultrasound elastography to quantify changes in the false vocal folds stiffness (in adduction and abduction) and symmetry associated with aging. Results of this pilot study may be used as a reference in future clinical patient care to assess age-related vocal cord changes and diagnose laryngeal pathologies.

Methods: After IRB approval and written informed consent obtained, we measured ultrasound strain and shear wave velocity (SWV) of the bilateral FVF in vocal fold abduction and adduction in 30 participants using a linear array transducer (4-10 MHz). Twenty-eight participants met inclusion criteria as healthy subjects for analysis. Mean strain of FVF produced by FVF movement from abduction to adduction was analyzed using 2-D speckle tracking software offline. A SWV ratio (SWVadduction – SWVabduction)/SWVabduction) was developed to test contractibility of FVF. Statistical analysis included one-way ANOVA to test the difference in mean strain, SWV in adduction and abduction, and SWV ratio among the three age groups; linear regression to analyze correlations of stiffness and motion between the right and left FVF; and intraclass correlation coefficient (ICC) to examine intra- and inter-observer reliability in performing SWE of FVF.

Results : The 28 healthy participants were divided into three age groups (10 of young 20-44y; 9 of mid-age 45-64y; and 9 of senior ≥65y). The SWV in FVF abduction was higher and SWV ratio was lower in seniors compared to young participants (p < 0.05). Good to excellent correlation of mean strain and SWV between both FVFs (R2 > 0.89). The reliability of performing SWE of FVF was moderate to excellent.

Conclusions: Ultrasound elastography is feasible to assess the stiffness, dynamic movement, and symmetry of adult FVF through a transcutaneous approach. Additionally, we detected age-related changes in an increase of FVF stiffness and decrease of FVF contractibility in seniors compared with young age participants in this healthy population without known vocal fold disorders. Additional study using ultrasound elastography to further assess age-related and pathologic changes in true vocal folds and false vocal folds disorders is warranted.