Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable view of the chest compared to prior chest x-ray from ___ and PET - CT from ___ . Hazy opacity overlying the left upper lung is unchanged and is compatible with left upper lobe mass and upper lobe collapse . There is elevation of left hemidiaphragm . The right lung remains clear . No acute osseous abnormality detected .
    OUTPUT:
    
No significant interval change . Known left upper lobe mass with complete atelectasis of the left upper lobe , better seen by prior CT scan . No definite superimposed acute cardiopulmonary process .