Subpleural bands are linear opacities seen on high-resolution CT
(HRCT) scans that appear close to the pleura, the membrane lining
the lungs. These bands are often located near the lung edges,
particularly in the lower lobes, and can be indicative of fibrosis,
scarring, or atelectasis (partial lung collapse). Subpleural bands are
frequently associated with conditions like interstitial lung disease
(ILD), chronic pulmonary fibrosis, and resolving pneumonia. The
pathogenesis involves localized scarring or fibrotic changes near
the pleural surface, leading to thickening and retraction, which
manifests as linear bands on imaging. While they may be seen as
part of benign, age-related changes in the lungs, the presence of
subpleural bands in conjunction with other findings (like
honeycombing or ground-glass opacities) can help in diagnosing
underlying chronic lung diseases.