When evaluating a series of HRCT scans, it is important to take note of both the dominant pattern or patterns and their distribution within the lungs. Honeycombing, reticulation, traction bronchiectasis, and volume loss are hallmark features of fibrosis,5,8 but scans from patients with fibrotic lung disease will often have signs of opacities such as ground glass opacity. The pattern of distribution will also give clues to the underlying disorder, as reviewed in the following section.