Monday, October 11, 2004

COPD X-RAY changes

Radiographic Findings

A posteroanterior and lateral chest film should be obtained primarily to exclude competing diagnoses. They may be entirely normal in mild disease. As COPD progresses, abnormalities reflect emphysema, hyperinflation, and pulmonary hypertension. Emphysema is manifested by an increased lucency of the lungs. In smokers, these changes are more prominent in the upper lobes, while in a1AT deficiency, they are more likely in basal zones. Local radiolucencies >1 cm in diameter and surrounded by hairline arcuate shadows indicate the presence of bullae and are highly specific for emphysema. With hyperinflation, the chest becomes vertically elongated with low flattened diaphragms. The heart shadow is also vertical and narrow. The retrosternal airspace is increased on the lateral view, and the sternal-diaphragmatic angle exceeds 90°. In the presence of pulmonary hypertension, the pulmonary arteries become enlarged and taper rapidly. The right heart border may become prominent and impinge on the retrosternal airspace. The presence of "dirty lung fields" may reflect the presence of bronchiolitis.

Computed tomography has greater sensitivity and specificity for emphysema than the plain film but is rarely necessary except for the diagnosis of bronchiectasis and evaluation of bullous disease. Nonhomogeneous distribution of emphysema is thought by some to be an indicator of suitability for lung volume reduction surgery (LVRS).

No comments:

Blog Archive