Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest . Improved inspiratory effort seen on the current exam . Although , on the lateral view , lung volumes are slightly low and there is an opacity projecting in the region of the costophrenic sulcus posteriorly . There is decrease in findings suggesting pulmonary edema compared to prior . There is no effusion or consolidation . Moderate cardiomegaly is seen . Left chest wall pacing device is again seen with leads in unchanged position . No acute osseous abnormality is identified .
    OUTPUT:
    
Opacity projecting in the region of the costophrenic sulcus posteriorly , potentially atelectasis given low lung volumes on the lateral but infection is also possible . Cardiomegaly without other superimposed acute cardiopulmonary process .