Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: When compared to prior , there has been improved aeration particularly at the left lung base . The lungs are grossly clear with some residual retrocardiac opacity , potentially atelectasis . There is no large effusion or pulmonary edema . Chin does obscure visualization of the lung apices . Moderate cardiomegaly is again noted . No acute osseous abnormalities . Right PICC is no longer visualized .
    OUTPUT:
    
Cardiomegaly . Improved but some persistent retrocardiac opacity which could be atelectasis . If clinical concern for infection , consider PA and lateral if patient is amenable . No pulmonary edema .