Assessment of Subcarinal Angle and Factors Determining it by using CT Scan

The present study entitled "Assessment of subcarinal angle and factors determining it by using CT scan" was done at General Municipal Hospital, Mumbai.

The present study entitled "CT assessment of subcarinal angle and its determinants" was done at General Municipal Hospital, Mumbai.

Subcarinal angle is the angle between first few centimeters of the lines drawn along inferior margins of two main bronchi8. carcinoma of the subcarinal lymph nodes is a challenge for the radiologist and pulmonologist as the subcarinal lymph nodes are among the most difficult to detect on chest radiographs6. Presence of a widened and distorted subcarinal angle enables the detection of subcarinal mass.

In the present study 64 adult individuals in the age group of 18–60 years of age of either sex (34 males and 30 females) attending the department of Radio diagnosis at General municipal Hospital, Mumbai for chest CT scan in whom CT scan images were normal as diagnosed by senior radiologist were studied. Subcarinal angle was measured and correlated with age, sex, body mass index, Presternal fat thickness, retro vertebral fat thickness, anteroposterior diameter and transverse diameter of thorax separately.

Normal range of subcarinal angle was 47 to 98 degrees (Mean ± standard deviation = 78.54 ± 12.07 degrees)

Subcarinal angle in male (Mean ± standard deviation = 72.69 ± 12.16 degrees, range=47–90 degrees), female (Mean ± standard deviation = 84.96 ± 7.72 degrees, range=61–98 degrees), in obese (Mean ± standard deviation = 84.9 ± 7.76 degrees, range=62–98 degrees) and in persons with normal body mass index (Mean ± standard deviation = 72.63 ± 12.60 degrees, range=47–92 degrees) were obtained. It was wider in females and in obese.

Fat deposited in subcarinal space enlarges the subcarinal angle. This is supported by strong positive correlation of subcarinal angle with body mass index.

Subcarinal angle shows significant positive correlation with presternal fat thickness and retro vertebral fat thickness and has no correlation with age, anteroposterior diameter of thorax and transverse diameter of thorax.

This set of standards can be used to determine the pathology in mediastinum.