Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs again demonstrate a small left apical pneumothorax which is decreased in size . The remainder of the exam is unchanged , demonstrating a normal cardiomediastinal silhouette and lungs which are well aerated and clear . There is no pleural effusion .
    OUTPUT:
    
Small left apical pneumothorax , which is persistent but decreased . A preliminary read was provided via telephone by Dr . ___ to Dr . ___ at ___ on ___ .