Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal contours are normal . On the frontal radiograph , lungs and pleural surfaces are clear . On the lateral view , a subtle rounded opacity projects in the retrosternal region , measuring approximately 3 cm in craniocaudad dimension . Considering the slightly obliqued positioning on the lateral view , this could potentially represent superimposition of the patient 's breast prosthesis rather than a true lung or mediastinal abnormality . There are no pleural effusions or acute skeletal findings .
    OUTPUT:
    
1 . No evidence of pneumonia . 2 . Questionable retrosternal opacity on lateral view , for which repeat lateral view with improved positioning is recommended for initial further evaluation .