The presentation of a dense shadow on chest radiograph is of clinical significance. It is mainly considered as tracheal foreign body, inflammation, tuberculous lesion, tumor disease and so on.
When in the process of taking the film, the ray will penetrate through the human tissue, in the image according to the different density and thickness of the tissue, showing different absorption phenomenon, so as to form a black and white contrast image. In chest radiographs, high-density tissues are usually found in bones or calcifications, etc., which show a white image, or high-density shadow, on the chest radiograph.
Generally, normal inflated lung tissue is uniformly transparent on chest radiographs. When there are lesions in the lungs, such as foreign bodies in the airways, inflammation, tuberculous lesions, and neoplastic diseases, they will appear in different patterns on chest radiographs. Abnormal signal shadows of different shapes, sizes, numbers and densities will be presented on the chest film.
Therefore, when the chest film presents high density shadow, should complete the relevant examination and follow the doctor’s instructions for further treatment.