Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest has been obtained with patient in semi-erect position . Comparison is made with the next preceding similar study of ___ . Unchanged position of tracheostomy cannula . PICC line has been pulled back by about 3 cm and terminates , now overlying the superior mediastinal structures , 2 cm above the carina . This is close to the expected junction with the subclavian vein , but appears acceptable . Other extensive right - sided pleural effusion is unchanged . Evidence of multiple sternotomy wires in midline as before . Within the heart shadow , the metallic components of a porcine aortic valve prosthesis is identified . Heart size can not be assessed on this single view chest examination because of other overlying structures .
    OUTPUT:
    
Grossly unchanged chest findings during the latest four days examination interval . PICC line has been withdrawn by a few centimeters .