Emphysema can be detected on chest X-rays. When it is severe, the total volume of the lungs in increased and the lungs appear darker than normal because less of the radiation is stopped by tissue. Computed tomography is a newer technique that shows emphysema in more detail than plain X-rays.


This cross-sectional computed tomogram (CT) near the top of the lungs shows the lungs and trachea (rounded, black, air-containing spot in the middle of the tissue that separates the two lungs). The anterior portion of the chest is at the top of the picture, and the triangular white, radiodense space at the bottom is the spinal column.

The lungs here show multiple, large, black, radiolucent, emphysematous spaces. The small, rounded, radiodense (white) circles and adjacent circles with black centers represent arteries and airways, respectively. They may best be seen in the mid left lung near the midline.

The spiky, radiodense, white nodule in the anterior (upper) portion of the left lung was removed because it was believed to be a cancer. Fortunately for the patient, it turned out to represent an infection with a mold, aspergillus, which has a tendency to grow in emphysematous lungs.

Normal CT

Compare this normal CT with that above. The lung tissue has a uniform radiodensity that is traversed by the vessels (solid circles or lines) and airways (open circles).

Emphysema on Microscopy

This is the microscopic appearance of one type of emphysema. A bronchiole once occupied the center of this emphysematous hole. Now, the bronchiole and its surrounding alveolar walls have been destroyed, but the other alveoli are spared. This type of emphysema is strongly related to smoking.

Find and outline the emphysema.

Find an area with normal alveolar walls and spaces.

What does emphysema do to gas exchange in the lung?
































Gas exchange is decreased as alveolar walls with their capillaries are destroyed. Both oxygen uptake and carbon dioxide elimination are decreased.





























































Normal lung