Mosaic attenuation

Mosaic attenuation is the presence of regions of differing attenuation appearing as patchy areas of black and white lung on HRCT. These correspond to affected and non-affected lung areas, respectively.

Different attenuation is a result of alterations in lung parenchymal perfusion that creates hyperperfused as well as hypoperfused lung areas.2,9,11

HRCT at the level of the upper lobes exhibits a “mosaic attenuation pattern” with patchy areas of increased attenuation (Courtesy of A. Oikonomou, ref.12)Mosaic attenuation