Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: This study is rather limited owing to poor positioning and underpenetration secondary to the patient 's body habitus . Allowing for these limitations : Metallic hardware from posterior fixation of the thoracic spine is present . The lungs are well expanded , without focal opacities although assessment of the left lung is limited . The cardiac size can not be evaluated due to rotation and AP projection but the patient has known cardiomegaly . There is no pneumothorax .
    OUTPUT:
    
No focal consolidation to suggest pneumonia . Not significantly changed compared with ___ .