Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral geographic foci of interstitial abnormality is present , most conspicuous in the left greater than right upper lobes . There is no pleural effusion , or pneumothorax . The cardiac silhouette is normal in size , the mediastinal contours are normal , although calcification of the aortic knob is present . There is partial visualization of lumbar fixation hardware , which appears uncomplicated ; anterolisthesis of L3 on L4 is mild .
    OUTPUT:
    
New bilateral interstitial abnormality , likely reflecting a viral or atypical pneumonia rather than heart failure given the normal cardiac size .