My husband went for a HRCT as a mandatory pre  test for Covid 19 for his eye surgery. While it was negative for Covid there was comment like small subpleural fibrotic densities found in right lower and middle lobe most likely of post infection etiology. He seems fine other wise , has good saturation and is able blow all 3 balls of spirometer. He did have pneumonia 15 years back. Is this something worrisome like progressive fibrosis.