KISEP Head and Neck Korean J Otolaryngol 2000;43:1241-6 후두 전산화단층촬영을 이용한 정상성인의 후두연골 골화에 관한 연구 박형진 공수근 서철주 김기태 이일우 이병주 노환중 고의경 전경명 왕수건 Ossification Patterns of Laryngeal Cartilage Using CT Scan Hyoung-Jin Park, MD, Soo-Keun Kong, MD, Chul-Ju Seo, MD, Ki-Tae Kim, MD, Il-Woo Lee, MD, Byung-Joo Lee, MD, Hwan-Jung Roh, MD, Eui-Kyung Goh, MD, Kyong-Myong Chon MD and Soo-Geun Wang, MD Department of Otolaryngology, College of Medicine, Pusan National University, Pusan, Korea ABSTRACT Background and ObjectivesCancer invasion of the laryngeal cartilage is mainly found in the ossified portion of cartilage and contraindication for conservation surgery of laryngopharyngeal cancer. Thus, it is an important factor to consider in planning the management of laryngopharyngeal cancer. Computed tomographic CT scan is an useful tool for the evaluation of laryngopharyngeal cancer, but it is difficult to distinguish cancer invasion from non-ossified cartilage regions by the CT scan. Knowledge of the precise ossification pattern will be useful to determine the cancer invasion of laryngeal cartilage. The purposes of this study include ossification pattern according to age, symmetry of ossification and incidence of bone marrow formation. Materials and MethodsFifty-three cases of normal laryngeal CT scans which were reviewed by two radiologists. They were all males, ranging in the ages from 40 to 69 mean age 53. Ossification degree was measured from the inferior cornu in the thyroid cartilage and the superior border of the posterior lamina in the cricoid cartilage. Age relation and symmetry of ossification and incidence of bone marrow formation were evaluated. ResultsThere were no correlation between age and degree of laryngeal cartilage ossification p0.05. But there was symmetry and definite pattern of ossification. Symmetry of ossification was 84.9 in the thyroid cartilage. Incidence of bone marrow formation was 60.6 in the thyroid cartilage and 82.8 in the cricoid cartilage. ConclusionThis study reveals that there is no ossification-age relationship, but the symmetry and the definite pattern of ossification in the laryngeal cartilage are useful clues in determining the cancer invasion on CT scan. Korean J Otolaryngol 2000;43:1241-6 KEY WORDSLaryngeal cartilage Ossification Computed tomography. 1241
골화범위의 측정 Fig. 1. Schematic illustration for division of thyroid lamina and calculation of ossification height in thyroid cartilage. Ossification height mmossified slices from inferior cornuslice interval Fig. 2. Ossification patterns of thyroid cartilage. Grade ossification of posterior margin including sup. and inf. cornua Grade additional ossification in lower half of thyroid lamina Grade additional ossification in upper half of thyroid lamina Grade ossification is done in whole thyroid lamina 1242 Korean J Otolaryngol 2000;43:1241-6
골화 양상에 따른 분류 골화의 대칭성 Fig. 3. Calculation of ossification height in cricoid cartilage. Ossification height mmossified slices from sup. border of post. laminaslice interval Table 1. Area of ossification in thyroid cartilage lamina Age Rt. Thyroid group D C B A Midline Lt. Thyroid A B C D Cricoid % 4049 1000 4811 6818 4622 5722 4622 6818 4811 1000 8222 5059 1000 5017 6422 5125 5724 5124 6323 5018 1000 7427 6069 995 4817 6418 4326 5625 4326 6418 4817 995 7519 1243
Table 2. Incidence of each ossification Grades Grade\Age 4049 5059 6069 % 7.6 8.3 12.4 46.2 25.0 37.5 46.2 50.0 31.3 0 16.7 18.8 Table 3. Incidence of bone marrow formation in thyroid and cricoid cartilage Age group Thyroid Cricoid % 4049 41.7 75.0 5059 66.7 86.9 6069 73.3 86.7 Table 4. Incidence of ossification of arytenoid cartilages Age group Incidence % 4049 84.6 5059 87.5 6069 68.8 1244 Korean J Otolaryngol 2000;43:1241-6
REFERENCES 1) Lee KD, Lee JD, Kim TH, Lee HK, Lee JS, Seo MS, et al. Pathologic findings of cartilage invasion in laryngeal cancer and correlation with computed tomography. Korean J Otolaryngol 1995; 38:424-36. 2) Castelijns JA, Becker M, Hermans R. Impact of cartilage invasion on treatment and prognosis of laryngeal cancer. Eur Radiol 1996; 6:156-69. 3) Kirchner JA. Invasion of the framework by laryngeal cancer. Acta Otolaryngol 1984;97:392-7. 4) Gregor RT, Lloyd GAS, Michaels L. Computed tomography of the larynx: A clinical and pathologic study. Head Neck Surg 1981;3: 284-96. 5) Kavanagh KT, Salazar JE, Babin RW. Bone marrow expasion of the thyroid cartilage: a source of confusion with malignant invasion in CT studies. J Comput Assist Tomogr 1985;9:177-9. 6) Chon KM, Wang SG, Goh EK, Roh HJ, Kim SG, Shim WY, et al. Cancer invasion to laryngeal cartilage after radiation therapy in salvaged laryngectomy specimen. Korean J Otolaryngol 1997;40: 1571-7. 1245
7) Yeager VL, Lawson C, Archer CR. Ossification of the laryngeal cartilages as it relates to computed tomography. Invest Radiol 1982; 17:11-9. 8) An WM, Kim BW. Ossification of the cartilages of the larynx, hyoid bone and trachea. The J of Catholic Medical College 1979; 32:441-7. 9) Keen JA, Wainwright J. Ossification of the thyroid, cricoid and arytenoid cartilages. South Afr J Lab Clin Med 1958;4:83-108. 10) Harrison DFN, Denny S. Ossification within the primate larynx. Acta Otolaryngol (stockh) 1983;95:440-6. 11) Hately W, Evison G, Samuel E. The pattern of ossification in the laryngeal cartilages-a radiological study. Brit J Radiol 1965;38: 585-91. 12) Archer CR, Yearger VL, Herbold DR. Computed tomography vs. histology of laryngeal cancer: Their value in predicting laryngeal cartilage invasion. Laryngoscope 1983;93:140-7. 13) Yeager VL, Archer CR. Anatomical routes for cancer invasion of laryngeal cartilages. Laryngoscope 1982;92:449-52. 14) Worning B. Roentgen examination of laryngeal and hypopharyngeal tumor. Acta Radiol (Stockh) 1934;15:8-14. 1246 Korean J Otolaryngol 2000;43:1241-6