Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates moderate improvement in degree of pulmonary vascular indistinctness , consistent with improving edema . Lung volumes continue to be low . No focal consolidation is definitively identified . There is a possible left pleural effusion . No large pneumothorax is identified .
    OUTPUT:
    
Improvement in pulmonary edema .