It has been estimated that over 25 million people have been exposed to asbestos in the past 40 years. Unfortunately, asbestos fibers in the lung can have serious consequences. It is convenient to divide these effects into those that involve primarily the pleural envelope and those that affect the substance of the lung itself.
Pleural plaques are abnormal collections of collagen that are attached to the parietal pleura.
They are usually bilateral and commonly involve the posterolateral aspect of the thorax. Asbestos fibers that exist within the plaques are submicroscopic and are concentrated in the areas of calcification. The finding of bilateral calcified plaques on chest x-ray is a relatively specific marker for asbestos exposure. The utility of CT or HRCT in these cases is relatively low . In this situation, HRCT is clearly superior.