Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild cardiomegaly has been stable compared to exams dating back to at least ___ . Aortic knob calcifications are redemonstrated , otherwise the hilar and mediastinal contours demonstrate mild pulmonary vascular engorgement . Diffuse hazy opacities overlying the lung fields bilaterally , as well as interstitial thickening is secondary to moderate pulmonary edema . There is an additional opacity in the left retrocardiac region . Small bilateral pleural effusions appear new compared to the CT from ___ .
    OUTPUT:
    
1 . Moderate pulmonary edema . 2 . Retrocardiac opacity may be secondary to a summation effect of the patient 's pulmonary edema , however an acute infectious process can not be excluded . 3 . New small bilateral pleural effusions .