超高精細CTを用いた喉頭軟骨の骨化についての検討

Abstract

Purpose : Ossification of the laryngeal cartilage has been investigated, including the pattern of ossification, age-related changes, and sex differences. This study aimed to examine the beginning, the processes, and sex differences of ossification of the laryngeal cartilage in Japanese patients using ultra-high-resolution computed tomography (UHRCT).Materials and methods : A total of 47 cases were included in the present study (male, n=34 ; female, n=13). UHRCT was performed, and ossification of the laryngeal cartilage was visualized in three-dimensional (3D) images. Reconstructed images were evaluated the degree and process of ossification of laryngeal cartilage was compared between males and females in various age groups.Results : In both sexes, ossification of the thyroid cartilage started at less than 20 years of age. The pattern of thyroid cartilage began in the inferior horn, and spread upward in the superior horn and extended toward the midline along the inferior borders, ending at the lamina. The beginning part in cricoid cartilage was the cricoarytenoid joints, and that in arytenoid was muscular processes. On UHRCT, ossification of the laryngeal cartilage characteristically showed a “figure 8 of thyroid laminae” sign that was constructed by the paramedian bar and two rounded non-ossified areas.Conclusion : Ossification of the thyroid cartilage began at <20 years of age. The degree of ossification of the thyroid cartilage will increase with age ; however, the degree and frequency of the ossification in males greater in comparison to females. Three-dimensional images allowed the evaluation of ossification of the laryngeal cartilage.