What is Normal

On ultrasound, the appendix appears as a blind-ended tubular structure in the long axis and a target-like or oval structure in the short axis.

A normal appendix has the following sonographic features:
–	Thin (≤ 6mm)
–	Layered appearance (gut signature). The lumen may contain air, fluid or debris
–	Compressible with gentle probe pressure
–	Minimal vascularity
–	No peristalsis
–	Difficult to locate (due to variable tip position)

 

Figure 5  Long-axis view of the appendix tip, demonstrating a normal appearance

 

Figure 7 Normal appendix in short axis

 

Figure 8: Normal appendix in cross-section (yellow arrow) off the colon (pink arrow) medially. Video courtesy of Dave Kirschner, used with permission.