Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Due to difficulty in patient positioning , only a supine portable radiograph was obtained . Multiple intact sternal wires and mediastinal clips denote prior cardiac surgery . There has been interval placement of a right IJ catheter terminating at the low SVC . The lung volumes are low , resulting in bronchovascular crowding . No pneumothorax is detected , although the right costophrenic angle is excluded on this study and the patient is supine .
    OUTPUT:
    
1 . Right IJ catheter terminating at the low SVC . 2 . No pneumothorax detected ; however , the technique was suboptimal for such evaluation . A repeat study can be considered if there remains a high clinical concern for pneumothorax .