Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable chest . Compared to the prior study , there has been further retraction of the left ribcage with increased displacement of the multiple rib fractures . The lung volume is lower than on the prior study . There is now denser opacity in the lower lung , demonstrated to be pulmonary contusions based on the prior CT . There is more extensive soft tissue air now tracking superiorly into the left neck and inferiorly into the abdomen . The chest tube is unchanged in position . There is no pneumothorax . No pleural effusion is present . The heart and mediastinum are unchanged in appearance . The right lung is clear .
    OUTPUT:
    
Compared to the prior study , there is a decrease in the left lung volume with retraction of the left ribcage causing increased displacement of the multiple rib fractures .