Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . Since the prior study , there has been interval increase in perihilar opacities , right greater than left , which may be due to infectious process with possible superimposed edema . The cardiac silhouette remains mildly enlarged with left ventricular configuration . The aortic knob is calcified . No large pleural effusion is seen , although trace effusions are difficult to exclude . No pneumothorax .
    OUTPUT:
    
Interval development of right perihilar opacity while could relate to asymmetric edema , infectious process is also in the differential . No large pleural effusion ; however , trace bilateral pleural effusions difficult to exclude .