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.

Pulmonary sarcoidosis: Classic radiographic finding.

We present the classic image findings of pulmonary sarcoidosis which is a rare disease in our country. A 31-year-old woman presents with an abnormal annual check up chest radiograph, which showed bilateral, symmetrical hilar nodes and a right paratracheal node enlargement without abnormal lung parenchyma. The physical examination, complete blood count, and blood chemistry, were unremarkable. Although many diseases can present with this abnormal image finding, but the combination of the nodal group involvement, the presence of intranodal calcification and nodal enhancement pattern, along with other pertinent positive findings on the chest CT scan, the diagnosis could be made.

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.

Chest radiographic evolution in fat embolism syndrome.

OBJECTIVE: To characterize the temporal chest radiographic findings of fat embolism syndrome. MATERIAL AND METHOD: Twenty-nine patients with clinically diagnosed fat embolism syndrome between 1988-1999 were retrospectively identified from the Trauma Registry of Haborview Medical Center, University of Washington. In twenty-two patients, complete medical records and serial chest radiographs were available. All images were reviewed by a dedicated thoracic radiologist. RESULTS: Two of 22 patients had normal radiographs throughout hospitalization, while 20/22 developed abnormal chest radiographs. The radiographic findings were consistent with non-specific diffuse pulmonary edema in all abnormal cases. The time to appearance of evident radiographic lung injury was < 24 hours of initial trauma in 10/20 (50%), between 24-48 hours in 4/20 (20%), between 48-72 hours in 5/20 (25%), and 1 patient (1/20, 5%) developed an abnormal chest radiograph after 72 hours. Ten of 20 patients (50%) with abnormal radiographs had complete resolution of the edema pattern within 1 week of development of opacities, 3/20 (15%) cases showed complete radiographic resolution between 1-2 weeks, 2/20 (10%) cases showed complete radiographic resolution between 2-3 weeks, 1/20 (5%) showed complete radiographic resolution between 3-4 weeks, and 4/20 (20%) died without resolution of the radiographic finding. CONCLUSION: The chest radiographic appearance of fat embolism syndrome is non-specific. Normal radiographs can also be seen. Most patients presenting with a normal initial radiograph develop radiographic evident abnormalities within 72 hours of injury and most cases showed radiographic resolution within 2 weeks of hospitalization. Although chest imaging play a little role in the clinical management of fat embolism syndrome, understanding of temporal presentation and evolution of the otherwise non-specific pulmonary opacities may help to avoid unnecessary evaluation in selected patients.