Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Two frontal images of the chest demonstrate well - expanded lungs . There is blunting of the left costophrenic angle due to some pleural thickening and likely small pleural effusion . Chest radiograph is otherwise essentially unchanged from prior imaging . There is some slight atelectasis at the right base . Cardiomediastinal silhouette is unchanged . Persistent elevation of the left hemidiaphragm is again seen . There is mild cardiomegaly which is stable .
    OUTPUT:
    
Small left pleural effusion , otherwise unchanged chest radiograph .