Performing the Scan

Positioning and probe selection. Place the patient in the supine position. The degree of elevation of the head of the bed has not been shown to make a significant difference in measurements (see References section). A low-frequency probe (3.5-5 MHz), such as a phased array or curvilinear probe, should be selected.

Landmarks. Two approaches may be used. The first is to obtain a subxiphoid view of the heart by placing the probe on the patient’s abdomen just below the xiphoid bone with the marker facing to the right of the patient. Once an appropriate subxiphoid view of the heart is obtained, the probe is rotated 90 degrees until the marker is pointing toward the head of the patient.

At this point, the IVC should be visualized in the longitudinal plane as it enters the right atrium.

The second approach is to scan using the liver as an acoustic window by placing the probe in the right anterior midaxillary line, similar to the placement for evaluating Morison’s pouch in the focused assessment with sonography for trauma (FAST) examination. The marker should be pointing to the head of the patient. By scanning more anteriorly and cephalad than the Morison’s pouch view, the IVC can be visualized running longitudinally adjacent to the liver and crossing the diaphragm. Following the vessel along until it enters the right atrium allows confirmation that the IVC is being visualized and not the aorta running parallel to it.