The location of the SjVO2 catheter depends on the diagnosis, the type and location of the brain lesions, and the technical feasibility. The SjVO2 catheter is placed retrograde in the dominant internal jugular vein, usually the right internal jugular vein. The dominant jugular foramen is larger on a computed tomography (CT) scan. The catheter tip is positioned at the jugular bulb of the internal jugular vein (the mastoid process, approximately at the C1-C2 interspace). An ultrasound scan device may be used to locate the jugular bulb to ease bedside placement. Catheter placement should be confirmed with a lateral skull or cervical spine x-ray. The catheter should be located at the level of and medial to the mastoid bone, above the lower C1 border.