Radiation exposure 6–12 months later is most often associated with which change?

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Multiple Choice

Radiation exposure 6–12 months later is most often associated with which change?

Radiation exposure causes two phases of lung injury: an early inflammatory pneumonitis and a later fibrotic phase. Six to twelve months after exposure, the fibrotic remodeling tends to predominate, leading to scarring, stiffness, and a restrictive pattern rather than ongoing active inflammation. Fibrosis results from ongoing fibroblast activation and collagen deposition, with imaging showing reticulation and volume loss that can progress toward honeycombing. Hypersensitivity pneumonitis and pneumoconiosis are not typical delayed effects of radiation: hypersensitivity pneumonitis is an immune reaction to inhaled antigens, and pneumoconiosis comes from chronic inhalation of mineral dust. Pneumonitis itself is more likely to occur earlier, within weeks to a few months after exposure.

Radiation exposure causes two phases of lung injury: an early inflammatory pneumonitis and a later fibrotic phase. Six to twelve months after exposure, the fibrotic remodeling tends to predominate, leading to scarring, stiffness, and a restrictive pattern rather than ongoing active inflammation. Fibrosis results from ongoing fibroblast activation and collagen deposition, with imaging showing reticulation and volume loss that can progress toward honeycombing. Hypersensitivity pneumonitis and pneumoconiosis are not typical delayed effects of radiation: hypersensitivity pneumonitis is an immune reaction to inhaled antigens, and pneumoconiosis comes from chronic inhalation of mineral dust. Pneumonitis itself is more likely to occur earlier, within weeks to a few months after exposure.

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