1.5-T MR imaging of organic laryngotracheal stenosis in a pediatric cohort predominantly younger than 7 years: protocol optimization and diagnostic performance.

OBJECTIVE

To develop a 1.5-T MR imaging protocol tailored for organic laryngotracheal stenosis (LTS) and to assess its performance in visualizing anatomy and pathologies.

MATERIALS AND METHODS

Presurgical laryngotracheal 1.5-T MR imaging was prospectively conducted in a cohort of 78 children with organic LTS from September 2021 to July 2023. Dedicated sequences were employed to acquire anatomical images of the laryngotracheal region. Image quality was assessed both qualitatively and quantitatively. Using intraoperative findings from laryngotracheal reconstruction (LTR) as the gold standard, the accuracy of preoperative MR imaging measurements of the cricoid cartilage and pathological diagnoses was evaluated.

RESULTS

The average age of seventy-eight children was 3.38 ± 2.95 years. Image quality of the larynx and cervical trachea was rated fair or good in 94.9% (74/78) and 96.2% (75/78) of cases, respectively. Interobserver agreement was high (Kappa ≥ 0.81). For 59 children with a score of 3, RTr-FSE-T2WI images presented significantly better signal-to-noise and contrast-to-noise ratios (p < 0.001). Compared with the surgical findings, MR imaging revealed no significant differences in the cricoid plate height, cricoid arch thickness, or short diameter of the narrowest laryngotracheal lumen (p > 0.05), except for the cricoid plate thickness (p = 0.002). Diagnostic accuracies of MR imaging for glottic, subglottic, and tracheal scars were 89.7%, 89.7% and 94.9%, respectively. For tracheomalacia and tracheoesophageal fistula, the accuracies were 85.9% and 97.4%, respectively.

CONCLUSIONS

Optimized 1.5-T MR imaging provides high-quality anatomical images, serving as a valuable imaging modality for preoperative evaluation of pediatric organic LTS.

KEY POINTS

Question The current imaging techniques used for preoperatively evaluating laryngotracheal conditions in children have notable limitations. Accurate evaluation primarily depends on intraoperative laryngoscopy. Findings The optimized 1.5-T MR sequence provides good contrast between normal and abnormal laryngotracheal tissues, facilitating precise presurgical evaluation of anatomical and structural abnormalities. Clinical relevance The 1.5-T MR sequence package is suitable for the preoperative evaluation of pediatric LTS. It provides detailed information on the cause and severity of stenosis and enables precise measurement of cricoid cartilage dimensions, aiding accurate surgical planning.