IT Quiz Answer – Jan 23, 2025

Here is the answer to our weekly Intelligent Thursday quiz!

Franz Wiesbauer, MD MPH
Franz Wiesbauer, MD MPH
10th Dec 2024 • 1m read

Pop Quiz: January 9, 2025

While performing a FAST exam on a trauma patient, you observe a black, anechoic stripe between the spleen and left kidney. What does this finding most likely indicate?


A. Normal variation of spleen parenchyma 
B. Artifact from bowel gas 
C. Hematoma in the renal cortex 
D. Free fluid in the space between the spleen and kidney

 

Check your answer!

The correct answer is D. Free fluid in the space between the spleen and kidney

Explanation:

During a FAST exam, free fluid in the left upper quadrant often first appears between the spleen and the diaphragm, then can course around the spleen and trickle down between the spleen and the kidney

Observing an anechoic black stripe in this region is indicative of free fluid, which is a critical finding in trauma patients.

Note that gas appears bright white on ultrasound. It creates a highly reflective surface, so ultrasound waves bounce back intensely, resulting in a bright, white hyperechoic line at the gas interface.


Since the kidneys are retroperitoneal structures and not the primary focus of this exam, bleeding in the renal cortex is unlikely to be observed during a FAST exam.
 

efAST
In addition to the standard FAST views (right upper quadrant, left upper quadrant, subxiphoid, and suprapubic views), eFAST includes views for evaluating the thoracic cavity. This typically involves examining the anterior chest to detect fluid or air around the lungs.

For more, check out our eFAST Essentials course.