Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest . No prior . There is retrocardiac opacity , which silhouettes the hemidiaphragm . This is compatible with pneumonia in the proper clinical setting . Superiorly , the left lung is clear as is the right lung . There is no effusion noting that the inferior most aspect of the costophrenic angle is excluded from the field of view . Cardiomediastinal silhouette is within normal limits for technique , positioning and relatively low lung volumes . Atherosclerotic calcifications are noted at the arch . Osseous and soft tissue structures are grossly unremarkable .
    OUTPUT:
    
Retrocardiac opacity compatible with pneumonia in the proper clinical setting . Repeat exam after treatment is suggested to document resolution .