Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . The heart size is within normal limits . No configurational abnormality is identified . Unremarkable appearance of thoracic aorta and mediastinal structures . The pulmonary vasculature is not congested . There exists a small area of poorly delineated parenchymal infiltrates projecting partially over the left heart border identified on the lateral view to occupy the posterior segment of the left lower lobe . No other acute pulmonary parenchymal infiltrates are present and the lateral and posterior pleural sinuses are free of any fluid accumulation . No pneumothorax seen in the apical area . Skeletal structures of the thorax grossly unremarkable . Our records do not include a previous chest examination available for comparison .
    OUTPUT:
    
Small poorly delineated patchy infiltrate in the left lower lobe posterior segment consistent with peribronchial pneumonia . No other pulmonary abnormalities are seen . Followup after successful treatment is recommended .