Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . Cardiomediastinal silhouette is normal . No large effusion or pneumothorax . No convincing evidence for pneumonia . A subtle 2 .5 x 1 .8 cm nodular opacity projecting in the left perihilar region not clearly present on prior chest radiograph , possibly the result of AP technique . No signs of edema or congestion . Bony structures are intact .
    OUTPUT:
    
Nodular left perihilar opacity , could represent overlapping structures though difficult to exclude a new nodule . Dedicated PA and lateral views of the chest recommended to resolve this finding .