Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . The pulmonary vasculature shows upper zone redistribution with indistinct margins suggesting mild vascular congestion . There is also more focal but vague patchy opacification at the left lung base , the latter possibly atelectasis . There is no definite pleural effusion . There is no pneumothorax . Moderate right - sided diaphragmatic elevation appears similar .
    OUTPUT:
    
Findings suggest mild vascular congestion . Patchy left basilar opacification , which is probably compatible with atelectasis but the possibility of infection could be considered in the appropriate clinical setting . In that event short - term follow - up radiographs may be helpful to reassess .