Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: An opacity overlying the right lower lobe could be pneumonia or rib sclerosis , best differentiated by oblique projections . Lungs are otherwise clear . Cardiomediastinal silhouette is normal . A small left pleural effusion may be present . There is no pneumothorax . Known T12 vertebral body compression fracture is not fully evaluated on this study . The ribs appear sclerotic and consistent with patient 's history of prostate cancer .
    OUTPUT:
    
Oblique radiographs recommended to distinguish possible right lower lobe pneumonia from sclerotic rib metastases .