Increased lung attenuation

Abstract

The increased lung attenuation pattern develops when the amount of air in the airspaces and in the lumen of the airways decreases (resulting from lung volume decrease or from partial or total filling of the airspaces) and when the soft tissue structures increase in size and/or amount, two phenomena that often occur simultaneously. When the changes are limited, the increased lung opacity is described as being a “ground-glass opacity” referring to the presence on CT of a hazy increase in lung opacity that does not obscure the underlying vessels. When more pronounced, i.e. when the vessels are obscured, the term “lung consolidation” or “consolidation” is used. This chapter explains the different causes of these two types of increased lung attenuation patterns and describes the elements that can be helpful to make a differential diagnosis.