11.07: Zone P5 – Between Nose & Lips
YOUR ASSIGNMENT FOR THIS LESSON
✅ Step #1: Review all content below.
✅ Step #2: Image the P5 zone on your own with your ultrasound, and using the checklist provided on this page, check off all key structures to be identified in this location.
TRANSDUCER POSITION AT P5
STANDARD P5 ORIENTATION:
TRANSVERSE
Midway between the lip and nares on the midline is the location of P5
- Identify the hyperechoic teeth deep in the P5 region, and adjust your depth of penetration to position this at the bottom of your screen.
- The hypoechoic linear band seen within the mid portion of the tissue imaged is the pars peripheralis portion of the orbicularis oris muscle - see diagram below
EXAMPLE OF TRANSVERSE IMAGE ACQUIRED AT P5
ANATOMICAL LEGEND FOR P5 LOCATION IN TRANSVERSE
DOPPLER IMAGES ACQUIRED AT P5 OF KEY VESSELS
- It can be very challenging in some patients to detect the main vessels in this region which are branches of the columellar arteries.
- Using power doppler can be useful here due to slower blood flow associated with these small vessels.
- Use lots of gel, it is easy to compress these vessels with the transducer which makes them harder to detect. The gel acts as a buffer alleviating pressure placed on these tissues.
- The branches will be superficial to the orbicularis oris muscle in most cases.