Anatomical reference values of tracheal bifurcation and age related evaluation of lung volumes

Aim: To reveal the age-related measurements of lung volumes by determining the anatomical reference points of the Bifurcatio tracheae in normal healthy individuals. In this way, it is to provide clinicians with the opportunity to make diagnosis and treatment easier by offering a chance to compare with healthy individuals in diseases involving these organs. In addition, it is to contribute to the anatomical structures that can be used for sex determination in terms of new data. Materials and Methods: A total of 20-60 (mean age 39.49±11.38) years of age, who underwent thorax CT with a Toshiba Aquilion 64 system device between January 1, 2015 and January 1, 2019, to Adıyaman University Training and Research Hospital Radiology Department and reported as healthy images of 200 cases (100 men and 100 women) were evaluated retrospectively. Age category was divided according to decades. The 1.1.7 version Horos application Bifurcatio tracheae angle and posterior projection of the cases were examined. At the same time, lung volumes of these cases were measured with Horos application. The volumes were grouped by considering the gender and age of the cases. Statistical analyzes were performed with the statistical package program in SPSS version 25.0 (IBM Inc., Chicago, IL, United States). Results: Out of a total of 200 cases ranging in age from 20-60 (mean age 39.49±11.38), 100 were male (mean age 39.22±11.65) and 100 were female (mean age 39.77± 11.11). The mean value of the right lung volume is 3113±342 ml in men and 2139±397 ml in women. The mean value of left lung volume is 2828±329 ml in men and 1898±388 ml in women. The projection of the bifurcatio tracheae was determined to be at the level of the T4 trunk in the majority of cases (52%), and most of them were found to be in the 30-39 age range. Considering the relationship between lung volumes and bifurcatio tracheae angle according to age category, no significance was observed. The bifurcatio tracheae angle was measured as 72 degrees in healthy men and 70 degrees in women, and the result was found to be statistically significant. Conclusion: It is a study in which the angle and volume measurements of the trachea and lungs, which are an important anatomical structure in the respiratory system, of healthy individuals are evaluated based on gender and age. It was determined that the reference point of the posterior projection of the bifurcatio tracheae was at the T4 level and this could be presented as a booklet. The bifurcatio tracheae angle with gender was found to be 72 degrees in healthy males and 70 degrees in females, and as a result of these measurements, it was determined that a new field could be created for the data to be used in sex determination. With the age-related evaluation of lung volumes, it may be easier to determine the pathological conditions that may occur in these organs. At the same time, the difference in lung volumes between men and women indicates that this measurement can be used based on gender. Keywords: Bifurcatio tracheae angle, bifurcatio tracheae posterior projection, lung volume, CT, horos application