Hippocrates, Galen, and a host of classical physicians wrote extensively on the spleen and its maladies. As I’m sure you recall, the spleen is tasked with the metabolism of black bile. Failure of the spleen to clear this fluid leads to melancholia.
Fast forward to now, and we also seek black fluid near the spleen. Using ultrasound.
It can be challenging to visualize the spleen due to the standard obstacles of patient habitus, bowel gas, rib shadows, or suboptimal positioning. If you become frustrated, just think back to your physical examination class where I’m sure you were taught to palpate the spleen tip. How did that work out for you?
Here are a few tips on better visualization of the spleen, useful for the perisplenic view of the FAST exam.
- The spleen is best imaged near the posterior axillary line above the ribs- the operator’s knuckles will brush the stretcher when holding the probe
- When the patient takes a breath in, the spleen moves inferiorly with the diaphragm
- When lung blocks the upper portion of spleen/diaphragm, start inferiorly and angle up through spleen, using the inferior aspect of the spleen as a window to superior aspect
- Instead of a ‘pure’ sagittal probe orientation, try to angle angle the probe obliquely to increase amount of probe between ribs. This will reduce the negative impact of rib shadows in the left upper quadrant view.
Here’s a schematic to illustrate that last point. Not that probe rotation increases the amount of window obtained between the ribs.
In the first ultrasound below, the rib shadows (arrows) obscure the view.
By rotating the probe, the spleen (S) is better visualized.
Like everything else, this requires a bit of practice. Remember, fluid can accumulate anywhere around the spleen and therefore it must be imaged in its entirety. It is NOT sufficient to view the interface between the spleen and right kidney, as if this view was just a mirror image of Morison’s Pouch.
