Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is interval progression of the multifocal airspace opacification which previously involved the right middle and lower lung zones as well as the left lower lung zone , which now also involves the mid and upper lung zones . The heart size is unchanged . No significant cephalization of pulmonary blood vessels . No widening of the vascular pedicle . No large pleural effusions .
    OUTPUT:
    
Nonspecific multifocal airspace opacification which shows interval progression in distribution . No interval change in the heart size , pulmonary cephalization or pleural effusions to suggest pulmonary edema .