Determination of subcarinal angle of trachea using computed tomography

Abstract

Background: Change in tracheal bifurcation angle (subcarinal angle) is an indirect marker of various cardiac, pulmonary and mediastinal pathologies. Helical computed tomography (CT) allows acquisition of volumetric set of data of the chest and can be used for accurate measurements of subcarinal angle using reconstructed images on a workstation using minimum intensity projection (MinIP).The objective of this study was to estimate normal subcarinal angle (SCA) of trachea by computed tomography and to assess its relationship with gender.Methods: This was an observational study comprising a study cohort of 552 patients comprising of 312 males and 240 females who were subjected to CT chest for various indications in our department. Patients with no underlying cardiac, mediastinal or pulmonary disease were included in the study. Spiral CT scan of chest was performed on 64-slice seimens CT SOMATOM and images were reconstructed with thickness of 1.5mm and the images were viewed in coronal reformatted minimum intensity projection (MinIP) for determination of subcarinal angle using the angle measuring tool provided in the workstationResults: The mean subcarinal angle (SCA) in males was (67.60±14.55). The mean subcarinal angle (SCA) in females was (78.90±11.04). Females had a higher mean SCA compared to males with a statistically significant difference (p-value <0.05).Conclusions: The mean SCA in females was higher compared to males with a statistically significant difference between the two. This study holds practical relevance with regard to the performance of invasive trachea-bronchial procedures like bronchoscopy and tracheal/bronchial intubation.

Detection of tracheal branching with computerized tomography: The relationship between the angles and age-gender

“…Parry et al [ 5 ] in the measurements made with thorax CT and MinIP technique on 552 patients aged 9-85 years in 2019, they found the mean subcarinal angle to be statistically significantly greater in women than in men, similar to our study (78.90° ± 11.04° vs 67.60° ± 14.55°, P < 0.05).…”

“…Examination of the tracheobronchial tree can be done with invasive and noninvasive methods such as bronchoscopy, bronchograms, computed tomography (CT), magnetic resonance imaging[ 2 , 3 , 5 ]. Most previous studies measured the subcarinal angle on chest radiographs using a goniometer[ 6 , 7 ].…”

“…In 2018, Fernandes et al [ 3 ] found the mean subcarinal angle of 69.75° ± 3.38° (range 66.37°-73.13°) in the measurements made with thorax CT and MinIP technique on 193 patients aged 20-60 years. Parry et al [ 5 ] in the measurements made with thorax CT and MinIP technique on 552 patients aged 9-85 years in 2019, they found the mean subcarinal angle to be statistically significantly larger in women than in men (78.90° ± 11.04° vs 67.60° ± 14.55°, P < 0.05). In 2018, Fernandes et al [ 3 ] and Parry et al [ 5 ] although the measurement methods are similar in his studies in 2019, the number of patients and measurement parameters are limited.…”

“…Parry et al [ 5 ] in the measurements made with thorax CT and MinIP technique on 552 patients aged 9-85 years in 2019, they found the mean subcarinal angle to be statistically significantly larger in women than in men (78.90° ± 11.04° vs 67.60° ± 14.55°, P < 0.05). In 2018, Fernandes et al [ 3 ] and Parry et al [ 5 ] although the measurement methods are similar in his studies in 2019, the number of patients and measurement parameters are limited. In addition, the relationship between age and gender and the subcarinal angle was not clarified.…”

Dysphagia Secondary to Esophageal Compression in a Patient with Decompensated Heart Failure

“…Because the carina is a dynamic structure, if the chest radiograph was taken in the patient's maximal inspiratory state, the carinal angle may have been narrowly measured compared to those in expiratory state. 15 The degree of inspiration might not be equally controlled for each chest radiograph because of difference in cooperation. Despite these limitations, chest radiography is readily obtainable, inexpensive, not technically difficult, and is widely performed.…”