MRI imaging versus histologic volumetric estimation of residual injection laryngoplasty material

Andrew Jay Bowen; Serban San-Marina; Danielle Hunter; Stephen Voss; Kathleen Bartemes; Slobodan Macura; Ryan Meloche; Andrew Mearns Spragg; Christine Lohse; Michael S Oldenburg; Dale C Ekbom

doi:10.1002/lio2.744

MRI imaging versus histologic volumetric estimation of residual injection laryngoplasty material

Laryngoscope Investig Otolaryngol. 2022 Feb 2;7(2):454-459. doi: 10.1002/lio2.744. eCollection 2022 Apr.

Affiliations

¹ Department of Otorhinolaryngology Mayo Clinic Rochester Minnesota USA.
² Department of Biochemistry and Molecular Biology & Metabolomics Core Mayo Clinic Rochester Minnesota USA.
³ Jellagen Pty Ltd St Mellons Cardiff UK.
⁴ Department of Health Sciences Research Mayo Clinic Rochester Minnesota USA.
⁵ Prevea Health Services Green Bay Wisconsin USA.

Abstract

Objectives: To examine the degree of agreement between MRI and histologically generated volumetric measurements of residual injection laryngoplasty material.

Methods: Following left recurrent laryngeal nerve transection, rabbit vocal cords were injected with jellyfish collagen, Cymetra®, or Restylane®. Laryngeal tissue was harvested 4 or 12 weeks post injection followed by MRI imaging and histologic cross-sectioning. Two raters estimated the volume of remaining injection material in specimens within MRI and histologic axial cross sections. Wilcoxon signed rank tests were employed to detect gross differences between inter-rater measurements and between imaging modalities across time. Agreement between rater measurements and imaging (histology and MRI) was assessed using intra-class correlation coefficients.

Results: Data was available from 16 rabbits sacrificed at 4 weeks (n = 8) and 12 weeks (n = 8). Inter-rater testing of MRI imaging revealed no significant differences (p > .05) between rater measurements across time points, and excellent agreement (0.93; 95% confidence interval 0.80-0.98) while histologically estimated volumes demonstrated a significant difference at 4 weeks (p < .05) and overall good agreement (0.89; 95% confidence interval 0.59-0.97). Comparison of MRI and histologically estimated volume measurements revealed significant differences at the 4-week time point (p < .05) but not at 12 weeks (p > .05). Overall, there is only moderate agreement between MRI and histology estimates (0.72; 95% confidence interval 0.22-0.90).

Conclusions: MRI imaging demonstrates good reliability and similar estimates of volume to histologically estimated measurements of residual injection laryngoplasty material at time points clinically relevant for future injection laryngoplasty experiments.

Level of evidence: NA.

Keywords: Cymetra®; Jellagen®; MRI; Restylane®; histology; injection laryngoplasty; jellyfish collagen; micronized acellular dermis.