Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding similar examination of ___ . Moderate cardiac enlargement as before . Somewhat widened and elongated thoracic aorta unchanged . The pulmonary vasculature again somewhat congested , but no acute interstitial or alveolar edema is identified , nor is there evidence of pleural effusion in lateral or posterior pleural sinuses . As already identified on the preceding chest examination , there is a sizable triangular density in the mediastinal contours of the left hemithorax blending and obscuring the central half of the left - sided diaphragm . In the left basal periphery , a thin plate additional atelectasis can be seen . No pneumothorax is identified . In comparison with the next preceding examination of yesterday , the findings are stable . Review of the next preceding chest examination of ___ demonstrates beginning changes that herald this atelectasis but still the major portion of the left lower lobe pulmonary parenchyma was aerated . Older chest examinations include that of ___ , in which some beginning atelectasis could be seen on the left base but by no means as massive as it exists now .
    OUTPUT:
    
Progressing sizable left lower lobe atelectasis as seen on PA and lateral chest examinations . Cause of this lesion is unclear . If evaluation is required , the next step would be a chest CT . As before , patient has a marked kyphotic curvature on the lateral view and typical endplate sclerosis as a characteristic for chronic renal osteopathy .