Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A neural stimulator device projects over the left chest . The cardiac , mediastinal and hilar contours appear stable . There is no pleural effusion or pneumothorax . The lateral view depicts a possible nodular opacity , which is newly apparent over posterior costophrenic sulci , possibly a summation shadow of normal vascular structures . Otherwise , the lungs appear clear .
    OUTPUT:
    
No evidence of acute cardiopulmonary disease . Possible posterior basilar nodule versus summation artifact . When clinically appropriate follow - up chest CT is recommended .