High-resolution computed tomography in silicosis: correlation with chest radiography and pulmonary function tests.
OBJECTIVE
To correlate tomographic findings with pulmonary function findings, as well as to compare chest X-ray findings with high resolution computed tomography (HRCT) findings, in patients with silicosis.


METHODS
A cross-sectional study was conducted in 44 non-smoking patients without a history of tuberculosis. Chest X-ray findings were classified according to the International Labour Organization recommendations. Using a semiquantitative system, the following HRCT findings were measured: the full extent of pulmonary involvement; parenchymal opacities; and emphysema. Spirometry and forced oscillation were performed. Pulmonary volumes were evaluated using the helium dilution method, and diffusing capacity of the lung for carbon monoxide (DLCO) was assessed.


RESULTS
Of the 44 patients studied, 41 were male. The mean age was 48.4 years. There were 4 patients who were classified as category 0 based on X-ray findings and as category 1 based on HRCT findings. Using HRCT scans, we identified progressive massive fibrosis in 33 patients, compared with only 23 patients when X-rays were used. Opacity score was found to correlate most closely with airflow, DLCO and compliance. Emphysema score correlated inversely with volume, DLCO and airflow. In this sample of patients presenting a predominance of large opacities (75% of the individuals), the deterioration of pulmonary function was associated with the extent of structural changes.


CONCLUSIONS
In the early detection of silicosis and the identification of progressive massive fibrosis, HRCT scans are superior to X-rays.
Department of Respiratory Function, Rio de Janeiro State University - Pedro Ernesto University Hospital, Rio de Janeiro, Brazil. phel.lop@uol.com.br
Agnaldo José
AJ
Lopes
Roberto
R
Mogami
Domenico
D
Capone
Bernardo
B
Tessarollo
Pedro Lopes
PL
de Melo
José Manoel
JM
Jansen
D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011653:Pulmonary Diffusing Capacity; D012129:Respiratory Function Tests; D012829:Silicosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012907:Smoking / Q000009:adverse effects; D013147:Spirometry; D014057:Tomography, X-Ray Computed / Q000379:methods*