Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left - sided PICC line is seen doubling back on itself within the left brachiocephalic vein at the origin of the SVC . The tip is not visualized as it is likely superimposed upon itself . An oblique view could confirm this or another revision could be attempted . Replacement by a fluoroscopic guidance should be considered . Inspiratory lung volumes are low . The lungs are clear without pleural effusion or pneumothorax . The cardiomediastinal silhouette is prominent in the setting of low lung volumes but unchanged from the preceding radiograph . A calcified mass in the left paratracheal region represents a known thyroid abnormality seen on chest CT of ___ .
    OUTPUT:
    
Left - sided PICC line with tip doubling back on itself in the left brachiocephalic vein should be repositioned .