Assessment of normal subcarinal angle on chest radiographs in adult Thai population.

Objective: The aim of this study is to determine the normal value of the subcarinal angle in the adult Thai population and whether there is a relationship between the subcarinal angle and the patient’s age, gender, and thoracic shape. Methods: The chest radiographs of 163 healthy patients were retrospectively reviewed. The subcarinal angle was analyzed with consensus by two radiologists. Quantitative variables are expressed as the mean ± standard deviation of the mean. The relationship of the subcarinal angle with the patient’s age, gender, and thoracic index were analysed using the Pearson correlation method. Results: A total of 163 patients (75 men and 88 women; age range 21-63 years; mean age 44 years) were enrolled. The mean subcarinal angle was 62°. There was no relationship between subcarinal angle and age, gender, and height or width of the thoracic cage. Conclusion: There is wide range of normal values for the subcarinal angle. The mean subcarinal angle was 62°. There was no relationship of the subcarinal angle to age, gender, or thoracic shape.

Progressive systemic sclerosis: Using high-resolution CT to detect and characterize interstitial lung disease in Siriraj Hospital.

Objective: To detect and characterize interstitial lung disease in patients with progressive systemic sclerosis in siriraj hospital using high-resolution computed tomography (HRCT) and to detect other associated findings in the chest. Methods: Retrospective reviewed chest radiography and HRCT of twenty patients with progressive systemic sclerosis during January 2000- January 2005. The HRCT scans were reviewed by two radiologists for reticular opacities (interlobular septal thickening, traction bronchiectasis, honeycombing and bronchovascular interstitial thickening), nodular pattern (miliary, centrilobular and perilymphatic nodule), consolidation and ground-glass opacities. The associated findings in the chest such as esophageal dilatation, mediastinal lymphadenopathy and main pulmonary artery enlargement were also evaluated. Results: Chest radiography detect interstitial lung disease in eighteen patients (90%). The findings are reticular opacities and fibrosis at both lower lobes. The HRCT shows interstitial lung disease in twenty patients (100%) with the greatest proportion of interlobular septal thickening (85%), followed by traction bronchiectasis (75%), honeycombing (40%) and ground-glass opacities (25%). The distribution of disease is peripheral and lower lung predominant. The associated findings: esophageal dilatation and mediastinal lymphadenopathy were presented in 55% of patients and main pulmonary artery enlargement was presented in 90% of patients. Conclusion: HRCT is more sensitive than chest radiography for detecting and characterize interstitial lung disease in patients with progressive systemic sclerosis. Our study has evidences of interstitial lung disease in all patients with greatest proportion of interlobular septal thickening, followed by traction bronchiectasis, honeycombing and ground-glass opacities. Moreover HRCT can recognize cases with predominance of inflammatory process and direct clinician into more aggressive treatment, may be benificial in preventing irreversible disease. HRCT was useful for detecting other associated findings in the chest such as esophageal dilatation, mediastinal lymphadenopathy and main pulmonary artery enlargement.