Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A cardiac device generator overlies the left hemi thorax . Leads terminate in the right atrium , right ventricle , and coronary sinus . There is a left pneumothorax . There is no significant mediastinal shift . Layering density overlying the mid and lower left lung may represent contrast material within the thoracic cavity . There is no consolidation .
    OUTPUT:
    
Left pneumothorax without evidence of mediastinal shift .