Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest has been obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . Marked cardiomegaly as before . No typical configurational abnormality is seen . Findings are therefore compatible with a diffuse enlargement of all heart chambers . No change in appearance of thoracic aorta . The pulmonary vasculature again demonstrates a typical upper zone re-distribution pattern and considerable perivascular haze in the lung bases . These findings may have regressed slightly . The previously identified and suspected density on the right base has resolved . On the other hand , one observes now a crowded pulmonary vasculature on the left base in the retrocardiac space , a finding which coincides with partial obliteration of the diaphragmatic contour and thus suggestive of an atelectasis in the left lower lobe posterior segment . As the lateral pleural sinus is still visible , the radiograph can not make the diagnosis of pleural effusions . No pneumothorax is present in the apical area .
    OUTPUT:
    
Mild regression of pulmonary congestive pattern , appearance of left lower lobe atelectasis . If the atelectasis may ___ elements of pneumonia , this will be decided on clinical findings .